Hello Antonio, some answers that will hopefully help you:
> 2: Can someone tell me how should I work with BlendChunk? I need to > make a complex (many materials and textures) object transparent. Note > that I'm not drawing the object myself but I loaded it from a .wrl. You need to find the materialgroups (is the OpenSG equivalent of a shape) of the objects (they should be above the geometries), fetch its material and add the BlendChunk with the correct parameters. > What about highlight the object (I mean making it brighter)? I guess > I should increase the component of the color of each material... > right? Right. > 3: Does OpenSG make Bounding Volumes computations? I mean, I need to > compute bounding volumes (spheres, boxes and cylinders) that are not > Axis aligned, do I have to do all the computations myself? I think > that Node::getVolume() gets only AABB, RIGHT? OpenSG does AABBs because they are incredibly easy and fast to calculate (they need to be updated fast for culling purposes if somethings changes within the scenegraph). Computing OOBBs (object oriented bounding boxes) is complex from the mathematic point of view and very slow. You need to do it on your own. If you have an implementation it would be fantastic if you could contribute it. > 4: Finally, how should I use Cubemaps and special effects? I use > CubicTextureChunk, set the five images, set EnvMode to GL_MODULATE > and add it as new state chunk in the simple material of my object but > nothing happens. Do shaders work the same (I mean setting paramneters > in a StateChunk and setting to the current material (I think it > doesn't matter if It's a SimpleMaterial or SimpletexturedMaterial, > right)?) We are not using the SimpleXXX materials anymore, because they hide complexity. Instead we use a ChunkMaterial as MaterialContainer and add a MaterialChunk with the color definitions. Besides that you need the CubeTextureChunk as well as a TexGenChunk (Functions S,T,R set to Reflection) for Texture Coordinate Creation as well as a TextureTransformChunk set to use the CameraBeacon. You may want to check our application VRED at http://www.vred.org to play around to find out how it works. HTH Matthias Stiller -- +---------------------+----------------------------+ | VREC GmbH | | | Matthias Stiller | tel: +49 6151 4921034 | | Robert-Bosch-Str. 7 | mobile: +49 177 7758639 | | 64293 Darmstadt | web: http://www.vrec.de | | Germany | mail: [EMAIL PROTECTED] | +---------------------+----------------------------+ ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_idv37&alloc_id865&op=click _______________________________________________ Opensg-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/opensg-users
