Layers show through others in 3-D space

Question

Hello everyone,
Since I moved to CS3, all my old AE files imported, and newly created projects, run into this problem in 3-D space quite regularly:
Often, a layer in 3-D space that is behind or colliding through another layer will still appear. It's tendency to appear seems to change throughout an animation, as the camera angle changes.
For example, as a camera of mine is placed further away from an object made up of many planes, the various planes will suddenly appear, though they will be the furthest away from the camera. These same planes will also flicker, frame to frame, over the course of the final render. Sometimes behaving as expected, hidden behind other layers, and sometimes appearing to be in front of everything.
I could see the layers colliding with one another could be considered 'messy' by the renderer (though it works perfectly in CS2), but having layers fully behind others and still appearing is a conceptual mystery to me.
Any ideas?
Thanks a lot for your time, in advance.
- BILL!

Answer 1

^David's advice is good but, since CS3, no longer works with 2D null objects - it needs to be a solid or similar layer. I usually create a small solid and push it way out of view of the camera. (Don't know why they changed that Null behavior!) But the advice is right on - using 2D objects to separate 3D layers in space is a great tool.
Perhaps the change in your results from AE7-CS2 to AE8-CS3 is due to a change in render engines. AE 7 had two render options: Basic Renderer and Advanced 3D Renderer. The Basic Renderer didn't allow 3D objects to intersect accurately. AE8-CS3 no longer has the option: it always uses the Advanced Renderer.
Perhaps you were using the Basic Renderer in AE7, which would account for the more accurate CS3 results you're now seeing with layers that are very close together in Z space.