Okay, I really need to bounce some ideas around and nobody in the room here has the slightest idea of what I’m talking about - so I’m hoping you guys might know
I want my program to take advantage of hardware T&L, so naturally the position of each object in the view frustum is calculated by glMultMatix. My ‘problem’:
I’m using my own picking algorithm and really I’d like to test against the lowest detail mesh of a given object. Of course, these are not transformed outside of the OpenGL pipeline. So I have to do my own transformations on them. This is kinda contra to the whole point of having hardware H&L in the first place. Are the glGet mechanisms and feedback buffer really that slow? I know I will have to use the CPU to transform my low detail meshes, so would using bounding boxes be better instead? Any tips to speed that up?
This got me worried about my ‘software culling’ too. What about glGetFloatv on the modelview and projection matrices? Is that potentially slow too? So I be using my own math to figure out these matrices for my plane equations?