[Algorithms] visualizing frustum planes?

[Michael S. H. <mic...@ud...>]

I'm attempting to implement the AABB culling code talked about here some time ago and I'm running into a general problem in visualizing the frustum planes used to cull objects based on their AABB's

I'm using both Klaus Hartmann's AABBCull sample and the Viewcull sample included with the OpenGL FAQ.

While the code generally works, I'm having some difficulty visualizing the relationship between the plane vector and the "distance" value stored with it, which I'm sure is the reason I can't quite figure out why the code generates intersection results when it should generate a full cull.

As you might guess, I'm fairly new to the world of 3d projection and I'm still wrapping my mind around all the transformations that take an object from "world" space to screen space.

Can anyone suggest a reference or way to visualize exactly what's going on with the plane extraction and how the vectors relate back to the AABB?