[Opensg-users] Help with geometry colors.

[Jon Guerin]

Hey guys, I'm in need of a little assistance.   I've created a model in 3DS and exported it as a Wavefront .OBJ file. I've loaded it up using OSG's file reader. I now need to change the colors of the vertices of the model. The Geometry nodes of the tree don't appear to have Color information, geo->getColors() returns NullFC. I attempt to create them.   I have a function that traverses through the tree returned by the file reader. I've created a GeoColors object and for each vertex in the Geometry, accessed through the GeoPositions object returned by the node's Geometry, I added a color to the GeoColors via col->addValue(c). Finally, I tell the Geometry node to use the new color object, geo->setColors(col).   This approach worked for a few of my earlier models, but not the later ones. I have no idea why. The first few models I used didn't have normals in the .OBJ file, and while they looked horrendous they still showed colors when rendered.   In the newer models, I have normal information in the .OBJ file. Now, it seems no matter what I do, creating color information for geometry does not do anything. The model always renders grey. I've tried several things; creating SimpleMaterial objects and setting glColorMaterial() to different values. Changing/adding material information to the geometry node results in a visible changes to the model, but the information from the Colors object I created and added seems to be ignored. Turning lighting on and off, changing glShadeModel(), do nothing. I've used begin/endEditCP() functions like in the tutorials, but that still doesn't make it work.   If anybody can help me out with my problem I'd appreciate it. I need to add color information to vertices in geometry nodes that have been obtained from importing .OBJ files and have it visible when rendering. I have a feeling that there's some gl___() command that I'm not aware of or something tricky having to do with materials or lighting, or perhaps I'm not adding the colors to the geometry correctly. Help?   Thanks!   .jg