I am trying to make a clip that shows a trip to the Earth's core.
It is like a fast tracking shot through a very long tunnel.
I started this by building 2,5D topology in After Effects. This was obvious, since the different layers should have a different appearance. (I don't need to stick to AE-3D if there is a better option.)
I spread about 2000 objects ("stones") on a z-range of -31850 to +31850 pixel. This is the cloud of objects the camera flies through.
The problem is: the tracking shot is way too slow, because the camera moves way to little distances.
You can do 3D in AE using some 3rd party plugins.
It may be that instead of having the camera travel, you create tunnels that move over the camera.
Also, there's no need for all pieces of the travel to be in one comp. Use transitions (passing through a rock, a dust cloud, molten lava, etc) to connect separate elements of the journey which are animated and constructed separately in different comps. This will enable you to move faster in AE, avoid crashes and limitations and make changes a lot easier.
One great plugin to use for 3d tunnels is FreeForm Pro (Free Form V2 can be used as well). I have a couple of tutorials here on the COW on how to do that. https://library.creativecow.net/jelescu_tudor/AE-3D-tunnels-FreeForm-Pro-1/... https://library.creativecow.net/jelescu_tudor/AE-3D-tunnels-FreeForm-Pro-2/...
For the example you pointed at 23:59, I would use FF Pro with a couple of moving textures that rotate like a 2 parallel cylinders, point the camera right in the middle and animate extrusion to give depth. Using precomps you could animate flat textures that can blend from one to another, in another precomp where they are applied to cylinders that rotate to create the impression of movement, and precomp that to create a moving texture and depth map for the layers you use with FreeForm Pro.
For the second example (1:1:33) you can use animated FF Pro layers (2) and a particle system from AE to give the impression of movement. Still the camera would not move.