Issue on image-3D:takes very long time and big memory sometimes

[ccxi1008]

I use a single image as input,and just use latents[0] to create pointclouds.

Sometimes it seems correct as follow,it only takes a few secondsc,and can successfully restore a ply file:

But most time it responds like this with so long time and so big memory:

The code and the input are totally the same.I'm wondering where's the problem and how to solve it.(Is it something about the Ptorch3d package?)Thanks!