Updated 20 July 2000- Holger Grahn
This document provides information about the new features and improvements in the different releases of Contact. It also describes some known limitations and difficulties.
Per default BS Contact computes a 3D representation for VRML Text nodes by getting True-Type outlines for each character and tesselates these into a set of triangles. This gives high quality text, but performance suffers due to the tesselation step and the high amount of triangles produced. VRML authors expressed the need for more flexible Font performance handling.
In Contact 4.3 there is the new option of creating a textured rectangle for each character. The user first must supply a special Font texture in a ImageTexture node and sets the fontstyle family attribute to "TEXTURE".
Shape {
appearance Appearance {
texture DEF FONTT ImageTexture { url "font512tr.gif" repeatS FALSE repeatT FALSE }
material Material { diffuseColor 1 1 1 }
}
geometry
Text { string [ "ABCDEFGHIJKLMNOPQRSTUVWXYZ" ]
fontStyle FontStyle { family ["TEXTURE"] justify "LEFT"
} } }
The Text attributes length and maxExtent, the FontStyle attributes size, spacing, leftToRight, topToBottom, justify and style = PLANE or ITALIC are implemented for TEXTURE text. The square texture map is divided into 16*16 cells for 256 different characters, the character 0 start in the upper left corner of the pixel image. The character width is scaled by 0.8. The Appearance node or Texture node should be reused between different text strings for speed. For special effects or fonts the texture map can be tuned. Using textures with alpha (or a transparent GIF) can give a transparent background. Using grayscale or black & white textures allows color changes using the Material diffuseColor.
Test Examples:
To further optimize the Text texture resolution and layout custom layout settings can be specified with up to 7 numbers after the family "TEXTURE" string. The format is "TEXTURE minChar maxChar cols rows aspect extraSpace shift"
| minChar | minimal character code - default 0 |
| maxChar | maximal character code - default 255 |
| cols | number of characters per texture horizontal - 16 |
| rows | number of character rows vertical - 16 |
| aspect | float, default 0.8 - width scaling factor |
| extraSpace | float, default 0.0 extra spacing between characters |
| shift | float default 0, italic shift factor for top of character box |
If an application only needs a certain continous range of characters, the texture can be optimized for higher resolution characters (or sprites).
The standard polygonal Text has been changed in the following ways: The default resolution for Text size 1.0 has been reduced. Text size 0.1 produces a coarse Font contour approximation, 10.0 a higher approximation.
The FontStyle attribute "OUTLINE" produces only fast lineset outline characters. This option can be only enabled for Contact 4.3 and might cause an exception in Versions prior to Contact 4.3.
The FontStyle attribute "EXTRUDE" produces extruded 3D Text with a depth of 1.0. Please beware of the high Triangle count possibly produced. (e.g. use the size 0.1 option for a coarser outline tesselation.)
It is also possible to provide a Windows True Type font name in the family setting.
In Contact 4.4 the following Windows specific language codes are recognized : ANSI, DEFAULT, SYMBOL, SHIFTJIS, HANGEUL, HANGUL, GB2312, CHINESEBIG, OEM, JOHAB, HEBREW, ARABIC, GREEK, TURKISH, VIETNAMESE, THAI, EASTEUROPE, RUSSIAN, MAC, BALTIC
The FontStyle attribute "WEIGHT#number" allows to fine tune the font weight, typical values are 0.. 1000 where bold is 700.
In the Direct3D version BS Contact 3D supports fullscreen mode rendering.
This capability has been improved to work with low-cost 3D Stereo glasses like the ELSA Revelator. The fullscreen mode can be choosen in the Preferences->Settings->Direct3D dialog.
To set up stereo viewing the graphics board and stereo driver must first configured, and the stereo width need to be adopted to the monitor size.
After clicking in the 3D window the key F5 switches to fullscreen, ESC switches back to window mode.
Here are some nice scenes with a good stereo effect:
Recent ELSA Driver version are also supporting stereo in windowed mode .
Layer3D enables to render subscene in a rectangular area. The background can be a solid color or transparent.
Layer3D is usefull for scene composition and VRML user interfaces. Many problems with the current HUD practice are solved with Layer3D.
More discussion and examples are provided here.
Material transparency now blended with transparent textures or transparent gif's. This is not VRML compliant, but was a demand from content developers.
The new Preferences->Performance dialog allows user fine tunining of rendering
performance. User of sites like www.cybertown.com with not so good CPU/3D performance
can set visibility scale to 0.5 to scale down the visibility distance and so
the amount of 3D data displayed.
The option visibilty scale scales any given explicit visibilityLimit in the
Navigation info and always scales LOD rangesl. For LOD without range the level
is choosen using the formula exp(distance from center to viewer / visibilityLimt
) * (level.length -1), priort to 4.3 the first level was choosen.
Trimmed NURBS extension nodes : Contour, Polyline2D, NurbsCurve2D, TrimmedSurface, Conversion utility from OpenIventor NURBS format to VRML, see NURBS project page for details.
The Browser.getCap(mode) call was extended to return memory statistic data like total & free physical memory as well as free texture memory in the Direct3D Version.
The are some more EMBED & OBJECT tag parameters available.
The Real Video module now displays status information.
As part of our development efforts for Pentium® III support, we have implemented NURBS technology in BS Contact 4.1. With NURBS, complex 3D curves can be represented with a minimum of data, allowing a new level of visual display and animation quality for Internet-delivered 3D graphics.
To learn about Contact's NURBS development, including NURBS-related settings in BS Contact, sample content, project results and our proposed NURBS extension for VRML97, see the NURBS project overview and the VRML NURBS proposal.
Intel Pentium III ISSE Instruction support
To take advantage of BS Contact's Pentium III support, you'll need a Pentium III PC running Windows 95/98 and Microsoft DirectX 6 or higher. You'll also need Microsoft Internet Explorer (version 3 or higher) or Netscape Navigator (version 3 or higher). Graphics cards with Intel i740, Matrox G200 or Riva TNT are recommended; best results can be seen with the latter.
Edit the settings in the Preferences dialog. To get there, right-click in the 3D window of BS Contact, then select Settings and Preferences. Or simply press Ctrl-F9. The settings of interest for Pentium III acceleration are described below; these settings can be made in the "Direct3D - more options" and "General" tabs.
Direct3D - more options
You can make the following settings:
Software-Lighting enables the software lighting, disabling the Direct3D lighting,
i.e. BS Contact computes lighting using the VRML specification's formulas. In
this mode the Pentium III acceleration can be activated by checking the "Use
Pentium III instructions" box. Enabling the "Use Direct3D Culling" option gives
a further performance boost if your graphics board supports this feature.
General
You can make the following settings in the General tab:
Enable the "run fullspeed setting" and in the DirectX section the HAL Driver.
Enabling "dither" and "smooth textures" usually yields a better visual appearance and shouldn't cause a reduction of frame rate with today's graphics boards. Generally, we recommend a high setting, e.g. 150, for "Amount of disk space to use" (set in "Cache Settings").
Some advanced features can only be set directly in the registry:
Direct3D.dxlevel - number (3 for Direct X 3, 5 for Direct X 5, 6 for Direct X 6, default 0)
Direct3D.maxverts - maximum number of vertices passed in a block to Direct3D (default setting is 1020)
Transform and Lighting as well as matrix operations are done with the ISSEi New Instruction set The VRML light model has been implemented. Supported lights are DirectionalLight, PointLight and SpotLight. The number of lights is limited to 64.
The performance gain depends enormously on the VRML scene. In scenes with a low number of polygons where transform and lighting require only a marginal amount of computation time, the acceleration of these computations can't result in an appreciable boost in system performance. However, the KNI can speed up BS Contact by as much as 50% if the CPU gets a heavy load.
Have a look at our benchmark page with various
complex scenes in order to see the performance boost of your PIII system.
Ideal content should contain larger meshes with full vertex sharing. Full
vertex sharing can be achieved by setting the following fields in an IndexedFaceSet
node:
creaseAngle 3.14
coordIndex ... as usual with coordinates referenced several times
coord Coordinate {... }
(optional)
texCoord
normal
(With the other fields at their defaults, ie. normalPerVertex TRUE solid TRUE )
As soon as a node contains normalIndex / texCoordIndex / colorIndex
or the default creaseAngle 0, sharing can get lost because each separate
instance of the tuple (colorIndex, normalIndex, texCoordIndex,
colorIndex) forms an internal vertex.
There is no limit on the number of vertices.
Two-sided lighting has been implemented (solid FALSE flag in IndexedFaceSet).
Of course this setting affects performance, because no backface culling can
be applied and the vertex normals are oriented toward the viewer for correct
lighting.
The following aspects of lighting are currently not implemented :
With small datasets and depending on the graphics driver, frame rate will not increase over some limit like 100 FPS using the i740 because the display.drv waits for display sync. This problem doesn't occur with the Matrox G200.
Using the Intel PIII-optimized Microsoft DirectX 6.1 release, we have seen some speed-up using the standard Direct3D transform/light code path in blaxxun Contact.
Beginning with Contact 4.1, raw mouse and keyboard input can be intercepted from javascript or an EAI eventOutObserver.
Events are reported via an SFNode Event node.
Event
{
eventOut SFString type
eventOut SFBool cancelBubble
eventOut SFBool returnValue
eventOut SFVec2f screen
eventOut SFVec2f client
eventOut SFVec2f position
eventOut SFBool altKey
eventOut SFBool ctrlKey
eventOut SFBool shiftKey
eventOut SFInt32 keyCode
eventOut SFInt32 button
}
type type property represents the event name as a string
property. cancelBubble cancelBubble property is used to control the bubbling
phase of event flow. If the property is set to true, the event will cease
bubbling at the current level. If the property is set to false, the event
will bubble up to its parent. The default value of this property is determined
by the event type. returnValue returnValue property is
checked by the DOM implementation after the event has been processed by
its event handlers. If the returnValue is false, the DOM
implementation does not execute any default actions associated with the
event. screen
screen.x indicates the horizontal coordinate at which
the event occurred relative to the origin of the screen coordinate system.
screen.y indicates the vertical coordinate at which the event
occurred relative to the origin of the screen coordinate system. client client.x indicates the horizontal coordinate at which the
event occurred relative to the DOM implementation's client area. client.y indicates the vertical coordinate at which the event
occurred relative to the DOM implementation's client area. positionposition.x indicates
the horizontal coordinate at which the event occurred relative to the
DOM implementation's normalized client area. position.y indicates the
vertical coordinate at which the event occurred relative to the DOM implementation's
normalized client area. altKey altKey indicates whether the 'Alt' key was depressed during
the firing of the event. ctrlKey ctrlKey indicates whether the 'Ctrl' key was depressed
during the firing of the event. shiftKey shiftKey indicates whether the shift key was depressed
during the firing of the event. keyCode keyCode holds the virtual key code value of
the key which was depressed if the event is a key event. Otherwise, the
value is zero. Currently the raw Win32 keycode is reported.button button is used to indicate which mouse button changed state.
This is a bitmask with the values 1 for left button, 2 for right and 4
for middle. During a buttonup event, the mask of the button causing the
event is reported.This extension is modeled after the W3C DOM Events.
Setting an observer requires the addition of a route or an eventOutObserver to the browser's SFNode eventOut event_changed. This is a code fragment for adding the event observer:
function initialize() {
// tell what events
m=Browser.eventMask;
oldMask=m;
m = m | (1<<4) | 1; // mouse up & down
Browser.eventMask = m;
// add event observer
Browser.addRoute(Browser,'event_changed',inputHandler,'onEvent');
}
The following are the supported mask values:
mousedown = 1
mousemove = 1<<1
mouseout = 1<<2
mouseover = 1<<3
mouseup = 1<<4
keydown = 1<<5
keyup = 1<<6
keypress = 1<<7
click = 1<<8,
dblclick = 1<<9
This is a code fragment for the event callback handler:
DEF inputHandler Script {
eventIn SFNode onEvent
url "javascript:
function onEvent(e,t) {
if (e.type == 'mousemove' && e.button == 0) {
return; // to many prints
}
print('Event type='+e.type+' at='+t);
print(' button='+e.button+' shiftKey='+e.shiftKey+' ctrlKey='+e.ctrlKey+' altKey='+e.altKey);
print(' position='+e.position+' keyCode='+e.keyCode+' ctrlKey='+e.ctrlKey+' altKey='+e.altKey);
if (e.type == 'mouseup' && e.button == 2) { // test we want to handle rbutton menu
e.returnValue = 0;
}
} "
}
All input event properties are reported using only one Event node. The default Browser eventHandling for that event can be turned off by setting the returnValue to 0. The event types keypress, click, mouseover, and mouseout are currently not supported.
Test Example: Mouse / Keyboard Input Test
BS Contact uses URNs (Uniform Resource Names) to reference media elements such as textures, sounds and objects according to a mechanism proposed by the Universal Media Working Group. Details of the proposal can be found here.
Laurent Gauthier of the Universail media Working Group provided incremental
installation of Universial Media files in Contact 4.3. The download location
can be edited in the CC3D cache settings. Media parts of UM residing on 4 Universal
Media mirror sites are incrementally installed.
With the default Setting "Verify once per session", VRML files are retrieved using the HTML browser's functions. All files retrieved by BS Contact are written to the cache with the server timestamp. The next time the files are needed, the current VRML server file date is compared with the VRML cache file timestamp. If the dates are identical, all referenced media files are read directly from the cache without further HTTP requests. This greatly improves loading performance if the world is revisited frequently.
In Contact 4.3 the URL's of Inline and EXTERNPROTO's are verified for change. Files considered corrupt like truncated WAV files, images or VRML with unexpected Syntax error (often resulting from interrupted downloads) are deleted from the cache.
If an author modifies an individual texture, the referring VRML file should also be touched in order to be refreshed by BS Contact. Media placed in locations containing "/cgi-bin/" or "/no_cache/" in the URL are retrieved each time.
The lastModified Date for an URL from the HTTP server is set as the creation time for the cache file; the modified date is the timestamp of last retrieval or cache storage. Applications can install VRML content directly to the Contact 3D cache with the proper timestamps, or can add a directory to the list of read-only directories. The cache is automatically cleaned from time to time.
Transparency is supported in the following forms :
Direct3D software drivers: stippled alpha (simulated alpha transparency via
pixel pattern), with DirectX 6 some support
OpenGL, Direct3D hardware: blended alpha transparency, some boards implement
dithered alpha only
Shape nodes with a fully transparent material are not drawn.
Transparent shapes are rendered after opaque objects, in order of the distance of their bounding boxes from the viewer. Currently a minor limitation is that transparent shapes are affected by global lights and top-level directional lights, but not by local directional lights. Shapes are sorted with respect to the distance of the bounding box to the viewer. In some configurations this results in unexpected rendering results. It is recommend to break up transparent objects in smaller parts, so that a better sort and drawing order can be achieved.
A transparent color index in GIF Textures or GIF MovieTexture is fully supported in all drivers. Support for textures with an alpha channel is driver-dependent: OpenGL, most Direct3D hardware drivers and the Direct3D RGB emulation driver support alpha formats; the Direct3D Ramp and MMX driver do not.
In Contact 4.4 the node DrawGroup { sortedAlpha FALSE children [...] } can be used to enforce a transparency drawing order. E.g. for a fake mirror effect with unlit shapes first the mirror is rendered (including any transparent objects in the sub scene graph), then a partly transparent mirror polygon is rendered, after that the normal scene graph (including any transparent objects.)
Tip: Creating PNG's with an Alpha channel in Adobe Photoshop:
Starting from a Gray or RGB image an Alpha channel can be created by creating a new channel.The Channel can be copied from one of the existing (GRAY, R or G OR B whichever gives the best contrast.) This channel can be globally adjusted using the Image->Apply Image operations. Using File-> Save a copy in PNG format the additional channel is exported as Alpha.
Lighting in version 4.0 is more compatible between OpenGL and Direct3D (RGB or hardware mode). The range parameter in light sources is ignored. OpenGL has a limit on the number of simultaneously active light sources. Ambient light in Direct3D is a global property and derived from the ambientIntensity of the light sources.
In third-person viewing mode, the user's avatar is displayed at the viewing position; the "rendering camera" displays an image from a new viewing position behind the avatar. The 'A' key or the context menu option "View my Avatar" toggles third-person viewing mode. The following keys (on the main keyboard, not the numeric keypad) control movement of the camera:
VRML viewpoints, navigation, ProximitySensors etc. are all relative to the position of the avatar, not to the third-person mode's camera.
The avatar VRML implementation can support certain animations on browser events like moving to a new position, begin/end of navigation action, world entering event.
The VRML ProximitySensor will report positions relative to the avatar position, not relative to the rendering camera. "Misuses" of the ProximitySensor as a helper to implement HUD displays will currently position the HUD in front of the avatar. For this reason an extra HUD node has been implemented as helper node. 3rd person viewing mode can be controlled from vrmlscript, see the Browser object extensions for details.
The navigation panel gives access to the walk navigation mode, viewpoint selection function and a slide function. The panel visibility can be toggled in the menu and in the Preferences dialog or via the embed / object parameter VRML-DASHBOARD=FALSE in the HTML page.
On some OpenGL display systems, display of the navigation panel reduces rendering performance.
Geometry objects are tested for visibility against the view frustrum. If the author specifies a bboxSize>=0 at a Group node level, a bounding box culling check is done for rendering, selection, terrain following and collision detection. Wrong bounding box values will result in wrong calculations, BS Contact currently does not update or re-compute the bounding boxes. The CullGroup Group extension node automatically computes internally a bounding box for the children scene graph.
New in version 4.0 is a geometric collision detection based on a box around
the old and new avatar positions, and the scene graph geometry. The collision
box is computed from the NavigationInfo collision distance, avatar height,
and step-over height. In the third-person mode these values are computed from
the bounding box of the avatar geometry and can also be specified in the avatar
prototype interface. The collision detection algorithm is very fast, but needs
some additional one-time preprocessing and memory the first time the avatar
approaches the object. Ground detection is done by firing a ray towards ground.
The initialize function of Scripts in EXTERNPROTO's are not always called. A workaround is to place the Script in the "traversed" scene graph part of the Proto scene graph.
Sounds are not not automatically disabled if switched off the scene graph using a Switch node. The workaround is to use the enable field of sounds to turn off sounds.
Only IndexedFaceSet supports continous crease angle values, other nodes only binary 0 or 3.14 values.
Circular node references are resulting in memory leaks. Workarounds are to
null SFNode values in the shutdown() function of a script or better restructering
the nodes to avoid loops.
"Excessive" proto structures with many fields are currently consuming to much memory.
There are limitations in ElevationGrid handling.
In Contact 4.3 Viewpoints outside of the initial scene bounding box is causing
wrong znear clipping, if the scene is animated and moves out of the border of
the initial bounding box.
BS Contact is optimized for the Microsoft Direct3D immediate mode rendering engine. Support includes DirectX 3, DirectX 5, DirectX 6, DirectSound, Direct3D Sound and DirectShow. Using low-cost Direct3D accelerator cards, exceptional VRML 3D speed and quality could be achieved. The DirectX interfaces are very close to the hardware, graphics boards and drivers are quickly evolving.
Windows 98 comes with DirectX 5 pre-installed.
Windows 2000 comes with Direct X 7 installed, but requires special new hardware
drivers from board vendors
Windows NT 4 with Service Pack 3 installed supports DirectX 3 (but without hardware
driver support).
Windows NT 4 without Service Pack 3 does not support Direct3D, only OpenGL.
In general, OpenGL software rendering runs faster on Windows NT than on Windows 95/98.
There are different Direct3D drivers available; features may vary and some drivers may not supply all rendering capabilities described in the VRML lighting model.
Direct3D hardware is installed if there is a checkmark next to the "Hardware" entry in the popup menu. BS Contact will also prompt for the use of a hardware device. If hardware works with your current desktop and graphics card configuration, it can be made the default setting by selecting it in the Direct3D tab of the Preferences dialog: press Ctrl-F9 or right-click in the 3D window, select Settings, then Preferences and, in the Direct3D tab, select "Hardware" in the Direct3D Driver drop-down box.
For a 16-bit desktop setting, enabling the Dither option in the Direct3D tab will usually improve display quality; for maximum speed, the "High speed" setting in the General tab needs to be enabled.
Most accelerators today support 3D only in a 16-bit (32000 or 65000) color setting. With this setting, the Windows dialog Settings->Control Panel->Display->Settings->Color palette would display "High Color (16-Bit)."
Mip-mapping can be activated by checking the "Mip Mapping" option in the Direct3D tab; after a resize or a reload, the hardware will automatically switch between different scaled-down versions of a texture (the mip-levels), making textures flicker less.
Trilinear mip-mapping can be enabled by selecting the settings "Smooth Textures" and "Mip Mapping". For a given pixel, the hardware first interpolates two color values in each of the two selected mip-levels and then interpolates between the two.
Newer graphics boards (e.g. those based on the Riva TNT chipset) support sort-independent scene antialiasing. This can increase visual quality along sharp edges of geometry and text.
The speed of software rendering depends on the size of the rendering window and the CPU speed.
Microsoft Direct3D Ramp Emulation Driver (Setting "High Speed")
This driver is optimized for speed, not for quality. Limitations:
Microsoft Direct3D RGB Emulation Driver (Setting "High Speed")
The Driver is optimized for quality not for speed; beginning with DirectX 6, there are many quality improvements and code paths for different CPU types.
Microsoft Direct3D MMX-Emulation driver (Setting "MMX Speed")
Limitation: internally supports only 8-Bit palette Textures, BS Contact needs to reduce all textures.
Enabling the Direct3D rendering options Dither, Mip Mapping, Smooth Textures and Anti Alias will have a negative impact on rendering speed of software drivers.
Limitations for all other Microsoft Direct3D Drivers
Specific Direct3D Hardware Driver Limitations
Some hardware drivers are have limitations depending on type of chip set or
version of the driver. In general, color per face, geometry shapes with more
then 1024 vertices are getting inefficient, especially if animated. Because
in the current implementation information is cached at the geometry level, it
is currently not possible to animate a given shape from an unlit to a lit state.
The following settings make a shape unlit:
Successful use of Direct3D hardware acceleration is directly related to the graphics card's memory, current screen mode, and size of the 3D window. Using low-resolution screen modes like 640*480*32K colors leaves more memory available for 3D buffers and textures. If Direct3D can't use the hardware because of too high memory requirements, BS Contact falls back to the Direct3D ramp software driver.
(Typical BS Contact error messages: "Create Surface for Z-Buffer failed" or "Create Surface for Window BackBuffer failed")
Recommended display settings for hardware use (Hardware == Direct3D HAL Driver):
As a rule of thumb, the required graphics board memory can be computed as
(pixel width of desktop * pixel height of desktop * 2)
+
(pixel width of 3D window * pixel height of 3D window * 2) *2
+ size of used textures in VRML scene (for non AGP boards)
(2 Bytes per pixel for a 16 bit color setting, a window backbuffer and a z-buffer need to be allocated)
If Direct3D hardware runs out of texture memory for storing all the textures, BS Contact automatically reduces texture bit formats and scales down textures, resulting in a "blockier" appearance of the images. More elegant solutions include switching to software rendering for a scene, releasing some memory on the graphics board by using a smaller window or lower desktop resolution, or upgrading to a graphics board with more memory (8 MB, 16 MB) or an AGP-based system.
Another issue is the number of different texture pixel formats a board supports and whether it only supports square textures. For example, for a board supporting only square texture formats, BS Contact scales up non-square textures. With a board that does not support palette 8 textures, BS Contact needs to expand GIF textures to a RGB format. Detailed information of a board's capabilities is provided by the DXView program part of the DirectX SDK.
On systems equipped with Intel AGP and a Direct3D AGP graphics board, much more texture memory is available. The amount of video memory is displayed in the Direct3D settings tab. This number should be much larger then the memory on the graphics board, otherwise the AGP support is not properly set up. On older Win95 systems, AGP support can be installed using the usbsup Windows update.
The default Direct3D start configuration can be specified in the "Settings->Preferences" dialog. Direct3D drivers evolve quickly, so it's a good idea to check the board vendor's website for graphics driver updates. Information about the installed driver version is available in the Windows Control Panel, Icon DirectX -> DirectDraw > Installed Drivers.
Running software modes on hardware is slow, and requires you to turn off the option "Use Video Memory" in the Direct3D settings tab of BS Contact. Rendering is then performed in the PC's main memory.
Preliminary support for Direct3D full-screen rendering is available. Ideally the VRML world should be displayed full-screen in the HTML browser with menu, tool and status bars disabled. Pressing F5 will toggle between full-screen and window mode. The full-screen display mode can be selected from the Direct3D Fullscreen Mode drop-down box in the Direct3D settings tab; the default is 640x480x16.
If there are display problems, try downloading an updated DirectX driver from the graphics board vendor's website. The drivers shipped with graphics boards are often out of date.
On systems equipped with an MMX CPU, the DirectX 3 "RGB Emulation Driver" provides MMX-specific acceleration. With DirectX 5 there is a separate "MMX speed" Direct3D driver. With DirectX 6 the "RGB Emulation Driver" automatically uses MMX specific codepaths.
Secondary Direct3D boards (3Dfx Voodoo and Voodoo2 etc.) which can only render full-screen and not inside a window are currently not supported.
Media Issues
Sound Support
BS Contact supports two different sound subsystems, Intel RSX 3D Sound
and Microsoft DirectSound.
Intel RSX 3D Sound
This sound system provides high-quality spatialized sound and does not require
the presence of Microsoft DirectX. WAV and MIDI file formats are supported,
only one MIDI sound can play at a time. Support from Intel for RSX has
been cancelled.
Microsoft DirectSound
DirectX provides basic sound support, DirectX 5 adds sound spatialization via
Direct3D sound. DirectSound depends on up-to-date sound drivers for the sound
card. Currently only uncompressed PCM WAV file formats are supported; sound
files can be gzip compressed.
Sound system configuration is done using the Sound tab in the Preferences dialog.
If the Microsoft Windows Mediaplayer is installed different Audio and Video formats are supported in the MovieTexture node. The URL information can be passed to Media Player API for streaming.
The URL protocols mms:// are treated as Window Media Media streamed URLs.
If the URL starts with the URN urn:inet:blaxxun.com:wm: then the URL string after the URN gets passed to Windows Media. The string should denote a fully qualified URL. Depending on Network connection this can be used for HTTP streaming of MP3's.
If the URL starts with the URN urn:inet:blaxxun.com:wm_cached: then the string after the URN is treated as a normal HTTP/FTP URL and the URL is downloaded first to the local hard disk and then passed to Windows Media. This method is advised if media are to be played several times or looped in order to avoid looped network streaming.
Sound is decoded and played by Windows Media, so no spatialization of the sound is currently supported. The sound is played in addition to other VRML sounds or Contact text to speeck if using the Direct Sound driver. No status message are displayed, usually the media starts playing after a while, once the the buffering phase is completed. The initial stream opening might currently block the Browser for a short while.
In oder to synchronize animations with streamed content, MovieTexture node is extended with an eventOut SFTime mediaTime, where mediaTime reports the current play position time information. Monitoring this event could be used to start animations, once the content starts playing after the buffering phase.
Test show that the following Media types are supported by Media Player 6.4
Sound formats:
MIDI, MP3, WAV, WMA, ASF
Video Formats:
MPEG, AVI, ASF, WMV
ASX files are not supported, usually an ASX files references a mms:// stream, this mms:// stream can be referenced directly in the url field of the MovieTexture.
By default the following file extensions are associated internally to Media Player : mid,midi,rmi,wav,au,snd,mp1,mp2,mpv2,mpv,mp3,mpa,mp4,avi,mpg,mpeg,mpe,ivf,asf,wma,wmv
Test Examples:
Real Player G2 Streaming Video & Sound
If RealPlayer G2 / RealPlayer Plus G2 is installed, RealAudio and RealVideo media are supported. The URL information is passed directly to the Real G2 subsystem and is played streamed.
The URL protocols pnm:// and rtsp:// are treated as Real Media URLs.
If the URL starts with the URN urn:inet:blaxxun.com:rma: then the string after the URN gets passed to Real G2 as URL. This allows media types to be passed to Real G2 instead of DirectShow.
If the URL starts with the URN urn:inet:blaxxun.com:rma_cached: then the string after the URN is treated as a normal HTTP/FTP URL and the URL is downloaded first to the local hard disk and then passed to Real G2. This method is advised if media are to be played several times or looped in order to avoid looped network streaming.
Sound is decoded and played by RealPlayer G2, so no spatialization or mixing with VRML sounds is supported. Only one Real G2 stream can play and parallel usage of Real Player is currentlly not working. No Real status message are displayed, usually the media starts playing after a while, once the the buffering phase is completed.
In oder to synchronize animations with streamed content, MovieTexture node is extended with an eventOut SFTime mediaTime, where mediaTime reports the G2 current play position time information. Monitoring this event could be used to start animations, once the content starts playing after the buffering phase.
A broad range of Audio and Video formats are supported by Real G2, if the codecs are installed. Examples include FLASH (.swf), MP3, m3u MP3 play lists etc.
By default the following file extensions are associated internally to Media Player : ra,ram,rmm,rav,rm,rmp,rv,smil,smi,m3u,pls,swf.
Test Examples:
Other options
Beside streaming from inside VRML another option is to embed the Real or Windows Media player into an HTML page. This has the benefit of additonal controls like title display, start, stop and olume controls. Even in this case two way control is possible using HTML & Contact3D scripting.
Using the Geometrek Deepwave Winamp plugin it is possible to write 3D VRML animations driven by spectrum data.
The following files should be present in the installation directory:
Even if the Netscape plug-in is being used, BS Contact references some DLLs which are only installed if a version of Microsoft Internet Explorer is being installed on the system.
If the installation fails, the recommended steps are:
BS Contact can be registered during installation as the default player for the MIME types model/vrml and x-world/x-vrml and is associated with the filename extensions .wrl, .wrz and .vrml. The registration for the .gz file extension has been removed in version 4.0.
Internet Explorer or Netscape Navigator will open a control registered for VRML with the following EMBED tag:
<EMBED SRC="test.wrl" HEIGHT=300 WIDTH=400></EMBED>
or if the user clicks on a link to a file with the .wrl extension:
<A HREF="http://www.myserver.com/test.wrl">Show VRML world</A>
In Internet Explorer the following OBJECT tag will work:
<OBJECT TYPE="model/vrml" HEIGHT=300 WIDTH=400>
<PARAM NAME="SRC" VALUE="test.wrl">
</OBJECT>
If multiple plug-ins are available for the mime type, the BS Contact 3D control can be directly specified in the Internet Explorer OBJECT tag by using BS Contact's classid.
<OBJECT CLASSID="clsid:4B6E3013-6E45-11D0-9309-0020AFE05CC8" HEIGHT=100%
WIDTH=100% ID=world>
<PARAM NAME="World" VALUE="http://www.bitmanagement.de/vrml/home/home2.wrl"
>
<EMBED src="http://www.bitmanagement.de/vrml/home/home2.wrl" height="100%"
width="100%">
</OBJECT>
BS Contact can be reregistered using the command
regsvr32 blaxxunCC3D.ocx
and unregistered using
regsvr32 /u blaxxunCC3D.ocx
Switching between the different versions of BS Contact or other VRML controls for IE is also possible using regsvr32, which usually resides in \windows\system.
For the Netscape Environment in addition the BS Contact Netscape plug-in DLL npbx3d.dll needs to be present in the Netscape/Navigator/Program/plugins directory. If there are already other plug-ins installed that handle the MIME type model/vrml, the corresponding DLLs need to be moved to another directory. Entering about:plugins in the URL input field of Navigator will list all currently installed plug-ins.
VRML-DASHBOARD 0|FALSE
turns off the navigation panel.
FULLSCREEN-MODE 1024x768x16
sets a fullscreen mode preference , built-in default is 640x480x16
TIMER-INTERVAL ulong number
Timerinterval in milliseconds
AVATAR-URL avatarUrl
Url for 3rd person mode avatar, default is avatar.wrl in the BS Contact install directory or the select Avatar in Multi-User enviroment.
AVATAR-DISPLAY 1|FALSE
turn on the 3rd person viewing mode
In Netscape browsers startup of the plugin if not Java EAI is required can be accelerated using the nojava option:
<EMBED SRC="test.wrl" HEIGHT=300 WIDTH=400 noJava></EMBED>
FORCE-HW TRUE
use the Hardware Direct3D Driver if present. There is an automatic fallback to software driver if there are no or limited hardware resources.
FORCE-RGB TRUE
In case the current driver preference does not support RGB lighting (e.g. the
default "High Speed" setting),
an Direct3D RGB mode capable driver is selected.
The option is recommended if the world-author requires best shading & texture quality with the potential drawbrack off slower rendering performance if no 3D hardware is present.
HW-PROBLEM-CHECK FALSE
This option disables the hardware problem popup dialog box.
This option is recommended if several CC3D instances are on one HTML page.
HIDE-CURSOR TRUE
hides the CC3D cursor.
Useful for applications providing their own feedback e.g. in fullscreen mode.
BS Contact supports VRML 97 and VRML 1.0 for backward compatibility.
A list of known issues is in the Tips, Known Problems and
Workarounds section.
The Script Node implements VrmlScript and a JavaScript subset as defined in Annex C of the VRML97 specification and in Proposal for a VRML Script Node Authorin by Chris Marrin, Jim Kent (Originally from Cosmo site).
Supported Script node URL strings are strings that begin with the VrmlScript identifier tag "vrmlscript:" or strings that begin with the JavaScript identifier tag "javascript:". The later is treated internally as "vrmlscript:". Also script can reside in files with the extension .vs or .js.
Java in the Script node is currently not supported.
BS Contact supports the VRML 2.0 external authoring interface proposal.
EAI for Microsoft Internet Explorer
The Java classes are installed in $(windows)\Java\classes\vrml. If there are problems compiling or running VRML EAI applets, remove any other VRML classes from the classpath. The classpath can be edited using regedit and editing the key HKEY_LOCAL_MACHINE\Software\Microsoft\Java VM\Classpath. Conflicting VRML zip-classes from other VRML browsers are removed during registration and saved to the CC3D.backup classpath.
EAI for Netscape Navigator / Communicator
The Java classes are installed in $(Netscape directory)\program\Java\classes\vrml. If there are problems compiling or running VRML EAI applets, remove any other VRML classes from the classpath.
EAI for C++ and other COM-capable languages
The EAI can be accessed via the COM-Interfaces defined in blaxxunCC3D.ocx and blaxxunVRML.tlb.
Some additional EAI calls like Browser.beginUpdate / endUpdate / saveWorld() are provided. Scripts running in the HTML page can directly send / retreive events to/from the scene graph, without the requirement of using an additional Java EAI applet.
For EAI developer information and sample programs see the Bitmanagement Developer
EAI information.
blaxxun BS Contact supports several VRML extensions. For broadest compatibility to the VRML specification these extensions should not be used until really required for a specific problem solution. Often scripting code can be made compatible by using extensions only in javascript code branches checking first for Browser.getName() & Browser.getVersion().
General
fields of built-in nodes are treated as exposedFields and can be read and changed, e.g. using the vrmlscript or the EAI API.
Navigation info tupe supports the following strings.
the special suffix _RESTRICTED disables the the Navigation mode sub-menu. This is applicable if the author does not want the user to change the navigation mode.
The following modes are recognized (case is ignored):
SLIDE
EXAMINE
ORBIT
ROTATE
WALK
PAN
FLY
FLY_PLANE
WALK
WALK_PLANE
LOOKAT
JUMP
Built-in nodes can be overwritten in a namespace with a Proto of the same name. In the PROTO body the original definition is still available.
The IndexedLineSet primitive is lighted, Vertex normals are computed similar to an IndexedFaceSet. Each sequence is treated as a polygon. As per VRML specification the color for unlit shapes is given using the emissiveColor of the Material field. So this treatment is VRML compatible if the Authors specifies emissiveColor and sets diffuseColor to black inorder to get a unlit shape.
vrmlscript Browser object extensions
additional member functions
float getCurrentTime() - gets the computer's current system time
float getTime() - gets the browser's current simulation time
float getWorldStartTime() - gets the time the world was loaded
void print(string); - print the string to the console. A typical use would be to debug scripts. Too many prints can slow down the performance due to the VRML Console update.
function x(value) { Browser.print(' value is '+value); }
In order to print timeStamps more easily, the following code fragment could
be used:
Browser.print('Time = '+ (timeStamp - Browser.getWorldStartTime()));
For compatibility with other VRML browsers, the built-in functions print(string); and trace(string); are supported.
createVrmlFromString - knows about PROTO definitions in the top-level VRML file. (non-standard !)
void setMyAvatar(node) - sets the avatar for third-person mode display
bool showMyAvatar(flag) - toggles third-person mode on/off
bool getThirdPersonView() -query if 3rd persion view mode is active
void setRenderMode(string) - changes rendering mode; supported values are Flat, Gouraud, Wireframe, Vertices. In addition, the OpenGL version supports Solid NonLighted BoundingBoxes.
void setNavigationMode(string) - changes navigation mode
string getNavigationMode() - gets the navigation mode (4.0)
void setCollisionDetection(flag) - changes collision detection mode
bool getCollisionDetection()
void setGravity(flag) - changes gravity, terrain following mode
bool getGravity()
void setHeadlight(flag) - changes headlight mode
bool getHeadLight() - returns current state of headlight
void setViewpointAnimation(flag) - If TRUE, viewpoint changes are animated;
if FALSE, viewpoint changes are immediate.
bool getViewpointAnimation() - returns current state of viewpoint animation
void setAvatarHeight(float value) - sets the avatar height, used for computing
distance of viewpoint to ground
void setCollisionDistance(float value) - changes the collision distance
float getCollisionDistance()
void setVisibilityLimit(float value) - changes visibility limit
float getVisibilityLimit()
void setWalkSpeed(float value) - changes walk speed
int getWindowSizeX() - returns the horizontal size in pixels of the rendering
window
int getWindowSizeY() - returns the vertical size in pixels of the rendering
window
float getWindowAspect() - get the aspect ratio (width/height) of the rendering
window, useful to adjust HUD display
float getAvatarHeight()
float getStepOverSize()
float getZNear() - return current actual znear clipping value
float getZFar() - return current actual zfar clipping value
Node computeRayHit (SFVec3f startPoint,SFVec3f endPoint, startingNode optional)
Computes an intersection of a ray with the scene graph. Result is null if no
intersection found or a PseudoNode RayHitInfo with the following information
stored:
PROTO RayHitInfo [
eventOut MFNode hitPath // the chain of grouping nodes, to the geometry node intersected eventOut SFVec3f hitNormal // normal at point of intersection eventOut SFVec3f hitPoint // point of intersection in global, world coordinates eventOut SFVec2f hitTexCoord // texture coordinate at point of intersection (without any texture matrix applied) eventOut SFMatrix hitMatrix // matrix transforming shape local coordinates to world coordinates eventOut SFVec3f hitNormalLocal eventOut SFVec3f hitPointLocal // intersection point in the shape's local coordinate system eventOut MFInt32 hitInfo // vertex index information ]
Example: rayhittest.wrl Navigate so that an object is in the center of the view and click the cylinder, information on hit will be displayed in the console.
setUnloadMode(int minNotActiveInlines, float percentage factor to purge)
set strategy for purging inlines from memory:
if the number of inlines currently not rendered is greater minActiveInlines,
purge up to (number * percentage ) inlines from memory
if percentage < 0 its an absolute number of inlines to purge
example:
setUnloadMode(100,0.05)
if (more than 100 inlines are currently not rendered)
delete 5 % of the inlines not used for the longest time
setBspMode(order) - set bsp Traversal order
setBspLoadingMode( order) - set bsp inline Traversal order
TRAVERSE_NORMAL 0
TRAVERSE_BACK_TO_FRONT 1
TRAVERSE_FRONT_TO_BACK 2
New in Version 4.0
getCap(what) - return browser capability information.
Example usage: adapt content to client platform, check if a certain feature like alpha blending is present.
Example: captest.wrl All available browser information is displayed in the console.
New in Version 4.1
boolean isKeyPressed(int keyCode) - determines if the virtual key determined by keyCode is down
string getWorldBaseURL() - returns the base URL of the toplevel world
string getBaseURL() - get the base URL for the script node
Url's inside EXTERNPROTO instanced VRML Nodes are relative to including VRML world. getBaseURL would return the baseUrl of the VRML file containing the Script node. So this call could be resolve for common authoring problems, if URL references in the PROTO should be relative to the implementing PROTO.
loadURLrel(MFString url,MFString parameters) - same as loadURL - but URL is relative to getBaseURL()
setViewpointByValue(SFVec3f position,SFRotation orientation, int mode) - set current viewpoint position to position / orientation
Mode can be set to the following :
bit 0 1: animated transistion 0 : not animated
bit 1 1: set absolute viewpoint (unbind any bound viewpoint)
bit 2 1: values are a relative move distance (left/right, up/down, > in/out,
look left/right, look up/down, roll,)
bit 3 1: check for collision, 0 not
bit 4 1: check for ground, 0 not
This function can be used to program a custom navigation.
For navigation a new relative move distance can be computed from user input
an passed to the Browser as Browser.setViewpointByValue(distance,rotation,(4+8+16)
);
In relative move (bit 2, value = 4) the orientation axis is interpreted as 3 rotation angles about the relative x y z axes of the camera.
getViewpointByValue(SFVec3f position,SFRotation orientation, int mode) - get current viewpoint position
mode 0 : return data of local viewpoint
mode 1 : global viewpoint, value of local viewpoint transformed to global coordinates
if bound viepoints is inside a Transform
mode 2 : third person mode viewpoint
void setSoundEnabled(flag) - if set to false lock the usage of the sound device
for this scene
flag getSoundEnabled() - returns current state of sound enabled state
Browsers object properties
The Browser object itself is a VRML node with certain events and fields. By adding ROUTEs from vrmlscript or eventOut Observers from the EAI, these events can be observed.
Access from vrmlscript: Browser.xxxx
Access from EAI: Browser.getEventIn(xxx) Browser.getEventOut(xxx)
eventIn MFNode set_myAvatarNodes - set my avatar nodes (for createVrmlFromURL
callback)
eventIn SFString set_myAvatarURL - set my avatar URL
eventIn SFString set_myAvatarName - set my avatar nickname
eventIn SFBool set_showMyAvatar - toggle third-person mode
exposedField SFString myAvatarURL - current avatar URL
exposedField SFNode boundAvatar - the bound (displayed) avatar node (may contain
wrapper around myAvatar)
exposedField SFNode myAvatar - node currently used as myAvatar node
exposedField SFString myAvatarName - current avatar nickname
exposedField SFVec3f followDolly - x,y,z relative translation distance for third-person
viewing mode
exposedField SFVec3f followOrbit - x,y rotation value for third person viewing
mode
exposedField SFVec3f followPan - x,y pan rotation value for third person viewing
mode
// observable eventOuts
eventOut SFTime time_changed - the master clock
eventOut SFVec3f viewpointPosition - global viewer postion
eventOut SFRotation viewpointOrientation
eventOut SFVec2f windowSize - rendering window width height
eventOut SFFloat windowAspect - aspect ratio of rendering window
exposedField MFNode viewpoints
exposedField SFNode boundViewpoint - the current bound viewpoint (top of stack)
exposedField MFNode boundViewpointStack - the other stacked viewpoints (if any)
exposedField SFNode boundNavigationInfo - the currently bound navigation info
exposedField MFNode boundNavigationInfoStack
exposedField SFNode boundFog - the currently bound fog
exposedField MFNode boundFogStack
exposedField SFNode boundBackground - the currently bound background node
exposedField MFNode boundBackgroundStack
exposedField SFString name - Browser name
exposedField SFString version - Browser version
exposedField SFString worldUrl - URL of the currently loaded world (set observer
to get a world changed notification)
exposedField MFNode overTouchSensors - list of TouchSensor's the mouse is over
exposedField MFNode activeVisibilitySensors - list of VisibilitySensors and
Occlusion nodes currently assumed to be visible
exposedField MFNode protoScenes - list of scenes with prototypes (loaded via
EXTERNPROTO URL ..)
New in Version 4.3
String getInstallDirectory() - returns the string of the directory blaxxun CC3D resides
int prefetch(mfNode argument, boolean loadInlnes=true, boolean loadTextures=true)
prefetch instructs the browser to load the Media resources listed in argument, parameter 1 and 2 are true by default. If argument directly references ImageTexture MovieTexture Inline Script or AudioClip nodes the return value is the number of those nodes loaded.
Node getScript() - returns an SFNode referering the Script node of the script. Often script authors need to have a "this" reference in a Script. The common Method using an extra SFNode field in the Script field list is also possible but could result in Memory Leaks in Contact.
bool setOption(string option, string optionValue)
string getOption(string option)
The following options string are supported :
Setting & querying Pentium III ISSE support :
print('ISSE = '+Browser.getOption('ISSE'));
Browser.setOption('ISSE','TRUE');
//Browser.setOption('ISSE','FALSE');
Overriding Nurbs Tessellation mode settings :
Browser.setOption('NurbsTesselationScale', '2.0');
Browser.setOption('NurbsTargetFps', '25');
Browser.setOption('NurbsTessellationMode', '0'); // 0 = static, 1=DYNAMIC, 2=
Frame Rate, 2= DYNAMIC & FRAME RATE
List of setOption values
antiAliasing TRUE/FALSE
collisionDetection "
dithering " dithering on/off
exactCollision "
fullScreen "
set fullscreen mode (D3D version)
gravity " set terrain following on/off
ISSE " Katmai ISSE instructions on/off
mipmap " mip/map on/off
lodScale float global scale factor for visibilityLimit, LOD (same as performance
visibiltz factor)
lightScale float global scale factor for light intensity
NurbsTesselationScale float NURBS Dialog settings
NurbsTargetFps float
NurbsTessellationMode int NURBS tesselation mode : 0 STATIC_TESSELATION, 1 DYNAMIC_TESSELATION,
2 FRAMERATE_TESSELATION 3 DYNAMIC_FRAMERATE_TESSELATION
smooth TRUE/FALSE Smooth texture filtering
soundQuality int SOUND quality settings (intial value)
texturing TRUE/FALSE Texturing enable / disable
Extensions to vrmlscript SFNode object
Methods
string getType() - get the type of the node as VRML nodeType or prototype name
string getName() - get the node's DEF name if available. The node name is not avaible if the node is part of a PROTO and the node in this instance was copied.
node copy() - creates a copy of the node (no deep copy on SFNode / MFNode fields)
fieldObject getEventIn(string eventInName) - get eventIn object of Node
boolean hasEventIn(string eventInName) - returns true if Node has an eventIn namved eventInName
fieldObject getEventOut(string eventOutName) - get eventOut object of Node
boolean hasEventOut(string eventOutName) - returns true if Node has an eventOut namved eventOutName
New in Version 4.3
VrmlMatrix getMatrix() - get Matrix of Transform, MatrixTransform or last Matrix of HUD, Billboard or related VRML 1.0 nodes
boolean setMatrix(vrmlMatrix) - set Matrix of Transform MatrixTransform nodes, false if matrix can not be set.
MFTime object
supports same members and methods as MFFloat object
Extensions to vrmlscript MFVec3f object
Methods:
setByVertexTransform(MFVec3f srcPoints, MFInt32 srcIndex,MFVec3f translation,MFRotation rotation,MFVec3f scale, MFRotation scaleOrientation,MFVec3f center)
This assignment function performs a series of transformations to coordinates in srcPoints and assigns the result to the object. The operation is comparable to a nested Transform scene graph used to animated a hierarichal model like an Avatar.
Up to the last 5 parameters can be omitted, in order to speed up the operation. if there a n group of vertices to transform, length of srcIndex must be n*3 and the length of each transformation data arraymust be at least n or 0.
The operation expressed in pseudo code:
VrmlMatrix matrixStack[];
var index;
for(index=0; index<srcIndex.length/3;index+=1) { // for all indices in groups by 3
var level=srcIndex[index*3]; // get the nesting level
var startIndex=srcIndex[index*3+1]; // start vertex index
var endIndex=srcIndex[index*3+2]; // end vertex index
// compute transformation, right most arguments could be omitted for speed
matrixStack[level]=m.setTransform(translation[index], rotation[index],
scaleFactor[index],scaleOrientation[index], center[index]) ;
if (level!=0) matrixStack[level].MultiplyRight( matrixStack[level-1]); // combine with parent
for(var i=startIndex;i<endIndex;i++) { // transform the Vec3f subset
this[i] = matrixStack[level] * srcPoints[i];
}
}
Extensions to vrmlscript Math object
double atan2(double dy, double dx) - arc tangent -PI .. PI
double cosh(double x)
double sinh(double x)
double tanh(double x)
double randomGaussian() - gaussian random number -1 ..1
double noise(double x) - evaluates solid noise function on x
SFString object extensions in 4.4
int string.getCharCodeAt(index); returns the character code as integer at position i
string string.fromCharCode(int1, .... intn); constructs & returns a new string composed out the given sequence of character codes
SFImage extensions
SFImage new SFImage(int width,int height, int componenents, MFFloat pixels) - construct SFImage using a float array of length widht*height*components. This function can be used to avoid the time consuming pixel packing in vrmlscript for dynamically computed SFImage objects.
Controlling download
BS Contact fetches URL objects and EXTERNPROTO's in the order encountered
during scene graph traversal, in the order top to bottom of file, depth first.
Currently not needed objects, because not "visible" due to a Switch, LOD or
BspTree node are only retreived if they become part of the visible scene graph.
Loading of Textures in the appearance node of a shape max be delayed until the shape's geometry becomes visible.
In order to preload currently unneeded objects, ImageTexture / MovieTexture / AudioClip nodes can be directly specified as children of Groups. The ordering of the nodes with url controls the download sequencing of the assets. The Appearance / Sound node references the asset by USE.
The BspTree or BspGroup node traverses child nodes nearer to the viewer first. This would mean Inline parts nearer to the viewer are earlier loaded then further away parts. Bsp - tree Parts outside the visibilityLimit (the viewing pyramid) are not fetched. The drawback is that once a new section of the world becomes visible there is some halting due to the decoding of image texture from harddisk to video memory.
The LOD node display lower levels if the requested level is an Inline node, currently not loaded.
A common request from content developers is to have more control over Resource loading notification and unloading capabilities.
The inline nodes behaves as a group-node, the children field is exposed to
access the nodes of the inline. By observing children_changed a notification
is sent, once an Inline node is loaded and processed.
The additional eventOut SFBool isLoaded indicates loading success, TRUE is sent
if the inline node is loaded and children are loaded, FALSE is sent if the inline
node's url couldn't be retreived or there was some other problem with the data.
In addition set_unload can be used to unload an Node from memory, however the
application should normally use this if its shure that the node is currentlly
not part of the visible node subsets (i.e. out of viewfrustrum, not in traversed
scene graph etc.)
This extened Inline version is described by the following prototype :
Inline {
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField MFString url []
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
eventOut SFBool isLoaded # TRUE if loaded & parsed sucessfully
eventIn SFBool set_unload # new in 4.1, send TRUE to unload Inline
from memory
}
ImageTexture {
... standard fields
eventOut SFBool isLoaded # new in 4.1
eventIn SFBool set_unload # new in 4.1, send TRUE to unload from memory
}
This node extension is not VRML97 compatbile, so it should be used with care.
It is possible to add an proper Externproto definition or using script code
checking the browser version :
EXTERNPROTO Inline2[
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField MFString url []
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
eventOut SFBool isLoaded
eventIn SFBool set_unload
] ["urn:inet:bitmanagement.de:node:Inline","nodes.wrl#Inline2"]
For textures one method is to use a MovieTexture and observe the duration_changed eventOut. Oberving the "last" asset, in file order can give a hint of a world completely loaded event. A new method in Version 4.1 is the additional eventOut SFBool isLoaded forImageTexture.
Extension Nodes:
Extensions nodes are native implemented EXTERNPROTO's. For VRML 97 conformance, a PROTO definition for the extension node should be added in the following way (using the MenuSensor node as an example):
EXTERNPROTO MenuSensor[
exposedField SFBool enabled
exposedField SFString title
exposedField MFInt32 choices
exposedField MFString descriptions
exposedField SFString position
eventOut SFBool isActive
eventOut SFInt32 choice ] ["urn:inet:bitmanagement.de:node:MenuSensor","http://www.bitmanagement.de/vrml/protos/nodes.wrl#MenuSensor"]
If possible most nodes have an usefull fallback implementation.
All built-in nodes can be referenced using the EXTERNPROTO URN syntax "urn:inet:bitmanagement.de:node:NodeType", the interface of the native node is used, not the interface of the EXTERNPROTO statement.
Contact parses PROTO ROUTES EXTERNPROTO in all places a node value is expected.
List of Nodes:
Discussed in BspTree section :
BspTree {
exposedField SFRotation plane 0 0 1 0
field SFNode front NULL
field SFNode overlap NULL
field SFNode back NULL
}
BspGroup { # new BS Contact 3.051
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
eventOut SFNode bspTree
}
Occlusion {
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField SFBool enabled TRUE
exposedField SFNode proxy NULL
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
eventOut SFBool isActive
eventOut SFTime enterTime
eventOut SFTime exitTime
}
Inclusion {
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField SFBool enabled TRUE
exposedField SFNode proxy NULL
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
eventOut SFBool isActive
eventOut SFTime enterTime
eventOut SFTime exitTime
}
MenuSensor displays a VRML defined Menu in the BS Contact right mouse button
popup menu
on activation of a menu entry, the corresponding choice value will be sent as
eventOut choice
a choices value of -1 indicated a menu separator
MenuSensor {
exposedField SFBool enabled TRUE # TRUE menu enabled,
FALSE disabled
exposedField SFString title "" # title
for submenu entry
exposedField MFInt32 choices [] # list of
numbers
exposedField MFString descriptions [] # description
for each menu entry
exposedField SFString position "" # "TOP" menu appears at the
top of the BS Contact menu
eventOut SFBool isActive
eventOut SFInt32 choice #
associated choices number for user selected menu entry
}
Example : menutest.wrl
New Nodes in version 3.051
Cullgroup is a group with an automatic bounding box computation for the children scene graph. Usefull for early render culling of complex scene graphs (e.g. Avatars)
CullGroup {
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
}
new in 3.05
Fog2 is like fog with the additional parameter visiblityStart for linear fog. Direct3D can not do exponential fog, linear fog starts per default at 0 in VRML causing often a too early blending with the fog color.
Fog2 {
exposedField SFColor color 1 1 1
exposedField SFString fogType "LINEAR"
exposedField SFFloat visibilityRange 0
exposedField SFFloat visibilityStart 0
exposedField SFFloat density 1
eventIn SFBool set_bind
eventOut SFBool isBound
}
new in 4.00
HUD {
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
}
This node equivalent to a VRML HUD construct using a Transform, ProximitySensor,
and Collision { collide FALSE }.
Children are displayed relative to the viewer and not relative to the avatar
position in 3rd person viewing mode.
Selection {
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField SFBool collide TRUE # as in Collision node
exposedField SFBool select TRUE # if false, children are not existing for Anchor / dragsensor selection
exposedField SFNode proxy NULL # proxy used for selection processing as well
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
}
Similar to a Collision node this node allows to give a mouse selection proxy (e.g. large Rectangle for Text, bigger box for a fine detailed geometry) or to turn off selection completely (e.g. in order to pick through transparent shapes).
4.3
Layer3D
Layer3D {
exposedField SFVec3f bboxSize -1 -1 -1
exposedField SFVec3f bboxCenter 0 0 0
eventIn MFNode addChildrenLayer
eventIn MFNode removeChildrenLayer
exposedField MFNode childrenLayer []
exposedField SFVec2f translation 0 0
exposedField SFInt32 depth 0
exposedField SFVec2f size -1 -1
exposedField SFNode background NULL
exposedField SFNode fog NULL
exposedField SFNode navigationInfo NULL
exposedField SFNode viewpoint NULL
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
}
See Layer pages for details.
CullGroup{
field SFVec3f bboxSize -1 -1 -1
field SFVec3f bboxCenter 0 0 0
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
# 4.3
exposedField SFBool lod FALSE
exposedField MFNode level [] #unlike LOD level 0 is already the children content
exposedField MFFloat range [] # same length as level
}
Instructs browser to do a cull checking operation on the scene graph, the bounding box will be computed from children. Optionally if lod = TRUE lod levels can be given, lod geometry is automatically scaled to the proper bounding box of children.
4.4 Nodes
DrawGroup
DrawGroup[
exposedField SFVec3f bboxSize -1 -1 -1
exposedField SFVec3f bboxCenter 0 0 0
exposedField SFBool sortedAlpha TRUE
exposedField MFNode drawOp []
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
]
DrawGroup is way for the content author to influence transparency processing. Wrapping a set of geometry into DrawGroup { sortedAlpha FALSE children ...} will process any geometry even transparent ones in the exact order given by children. This can be used for mirror like effects or turn off delayed alpha blending for sets of geometry with f bi-level transparency only. drawOp is not yet supported and is intended in the future for certain drawing effects.
Cell & Portals
see Cell & Portal proposal
Cell {
exposedField SFVec3f bboxSize -1 -1 -1
exposedField SFVec3f bboxCenter 0 0 0
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
exposedField MFNode portals []
}
Portal {
exposedField SFBool enabled TRUE
exposedField SFBool ccw TRUE
exposedField SFNode coord NULL
exposedField SFNode cell NULL
}
CellGroup {
exposedField SFVec3f bboxSize -1 -1 -1
exposedField SFVec3f bboxCenter 0 0 0
exposedField SFInt32 range -50
exposedField MFNode cells []
exposedField MFNode children []
eventIn MFNode addChildren
eventIn MFNode removeChildren
eventOut MFNode activeCells
}
Particles
see see particles system page
PROTO Particles {
exposedField SFVec3f bboxSize -1 -1 -1
exposedField SFVec3f bboxCenter 0 0 0
exposedField SFFloat lodRange 100
exposedField SFBool enabled TRUE
exposedField SFFloat particleRadius 0.1
exposedField SFFloat particleRadiusVariation 0
exposedField SFFloat particleRadiusRate 0
exposedField SFNode geometry NULL
exposedField SFVec3f emitterPosition 0 3 0
exposedField SFFloat emitterRadius 0
exposedField SFFloat emitterSpread 0.25
exposedField SFVec3f emitVelocity 2.5 5 2.5
exposedField SFFloat emitVelocityVariation 0.5
exposedField SFRotation emitterOrientation 0 1 0 0
exposedField SFFloat creationRate 500
exposedField SFFloat creationRateVariation 0
exposedField SFInt32 maxParticles 500
exposedField SFTime maxLifeTime 5
exposedField SFFloat maxLifeTimeVariation 0
exposedField SFVec3f gravity 0 -9.8 0
exposedField SFVec3f acceleration 0 0 0
exposedField SFColor emitColor 1 1 1
exposedField SFColor fadeColor 0.25 0.25 0.25
exposedField SFFloat fadeAlpha 1.0
exposedField SFFloat fadeRate 0.25
exposedField SFInt32 numTrails 0
exposedField SFInt32 numSparks 0
exposedField SFVec3f sparkGravity 0 -5 0
exposedField SFColor sparkFadeColor 0 0 0
}
Acknowledgements
Paul S. Strauss – SGI for providing the QvLib a VRML 1.0 Parser
Chris Marrin & Jim Kent - Silicon Graphics for providing the vrmlscript
parser
"Portions of this software are based in part on the VRMLScript Interpreter written
by Silicon Graphics, Inc., Mountain View, California, USA."
the Independent JPEG Group's for providing libjpeg – ftp://ftp.uu.net/graphics/jpeg
„this software is based in part on the work of the Independent JPEG Group".
Jean-loup Gailly and Mark Adler for providing zlib. ZLIB Homepage
Guy Eric Schalnat and contributors for providing libpng. PNG Homepage
Michael Vollmer and Dean Macri – Intel for providing assistence for the Intel Pentium III ISSE code and NurbsSurface implementation
S. Gottschalk - The University of North Carolina for providing Rapid & V-COLLIDE (see license information in rapid.h - use for profit purposes requires a license from UNC)
Laurent Gauthier - incremental Universal
Media installers.