View Full Version : Opengl as a raytracer preview window

02-23-2009, 12:09 PM
Hello all.

I posted about a bit of a problem I was having a while back with opengl and my raytracer output differing a bit.

I wasn't able to fix it, so I'm gonna ask a few questions, and see if i've missed something stupid.

1. My input files are in maya obj from 3dsmax and deep exploration. Now these will be in object space when they are loaded right?
OpenGL then transforms them through the projection-modelview matrix stack to render them on the screen.

Now, I don't transform them through anything at all.

When I fire rays at them (i use the opengl viewport parameters), will the rays miss them (or give weird output) if I don't transform the models verts through the matrix transform pipeline before raycasting?

Something that might help is that when the camera is parallel to the z axis, the output looks almost correct, and it is most corrupted and warped when the camera is at a large angle.

Do I need to transform the verts through the transform pipeline?
The reason I ask, is that I was using GLUUnproject, which returns a pixel in screen coordinates into a world space position.

Can anyone help? I'm going crazy here.