-
Making particles automatically disappear behind 3D layers. Expressions? Plugins?
I’m working on a long animation which involves many many 2D layers adding together to make objects in a 3D space. (I’m aware this would’ve been easier in C4D or something but I did it this way to challenge myself and because it looks cool shh).

so as you can see each layer has been carefully placed in 3D space.
I would love to have little particles flying around the room for the duration of the 3 minute video but I’ve become aware that although ae’s particle systems follow the camera movement, they do so only within a 2D layer that can either be placed above or below 3D layers so the particles in the back don’t automatically disappear behind 3D objects, and the particles in the front will only be in front if they’re at the top of the layer stack.I’ve looked through a couple of other forums and all of which had pretty decent workarounds for simple projects such as masking things out, cutting particle layers based on WHEN the particles pass in front or behind, etc. But as is probably evident that isn’t an option for my project, casting aside visual compromise and unrelenting tedium.
So I ask whether anyone knows of or can figure out a method using expressions, free plugins, depth mattes (I don’t know what depth mattes are) or anything that springs to mind to make this entire process fully automated throughout the video.
A few things to note:
– Camera moves and rotates constantly
– Camera only stays on one side of the box facing in roughly the same direction the whole time (never turns more than 45 degrees left or right, never strafes left or right).
– Objects in the scene stay in place but rotate and move around complexly.
– I would still love to be able to apply an animated texture to the particles if possible, but this isn’t essential.
– When I say 2D layers I mean layers that have zero depth but YES have the 3D layer option checked.Thanks a tonne,
Jesse.