I'm attempting to parse collada files that have been produced in Sketchup (free) via the Google Earth export function. The files are displayed in OpenGL. Everything is working fine except for my materials. The colors do not show up. I thought I would check the basics, and start with the normals. I'm deindexing the positions, normals, and texture coordinates for use in OpenGL. I've confirmed my deindexer against Collada Refinery outputs. The question I have is, are the sketchup normals vertex or surface normals? I've been assuming that they are vertex normals. The textured triangles are coming out alright using the same methods. The collada file is in z-up and opengl is y-up, do I need to convert the normals so that they are y-up? I guess that's more of an opengl question.
Any help is appreciated.