Caching geometry in max

Coding
1

does someone know a tool for caching geometry in 3dsmax like the point cache modifier, but without the constraint of constant topology.
In other words, I need it to save the entire geometry every frame from scratch,
including vertexes, edges, faces, mat IDs, and uvw coords on all channels.

Has someone encountered anything like this?
Thanks,
Matan.

2

Copy the mesh at each frame and hide/freeze it?

It’s not as if you are saving much memory by not having an actual node if all the geometry data is being cached.

the Snapshot and SnapshotAsMesh command will grab your mesh, collapsed, at the current time - might be worth a (snap)shot.

There might be more elegant ways of doing this; but that might work for a quick’n’dirty solution.

3

Thanks Alex,
you gave me an idea for how to solve this problem.
what I did was to create a snapshot for every frame and save it to a separate file.
then I create an xref object and load the object from the file of the first frame.
then using a script controller I change the path of the xref object every frame to the file
containing the snapshot of this frame. Another approach is to save all the snapshots to the same file and then changing the object name in the xref object every frame.
I am also considering using containers instead.
I have two unsolved issue with this solution:

  1. some update problems with changing the xref object file path
  2. I need to find a way to make the script controller update on every frame correctly.
4

Motion blur probably wont work with the snapshotting since you lose the motion of the vertices between frames. Realflow .bin meshes go around this by baking the velocity per vertex when building meshes that change topology in every frame. The loader has a motion blur multiplier for passing that information to the renderer. I haven’t exhaustively tested motion segmenting quality between frames but there might be issues with that as well. Im not sure about containers, havent tried those, doesnt seem to me that it would make a difference with this issue. Of course if you got with adding motion blur in post this is not an issue.
As a sidenote I suggest you check out the blurbeta tools they got some neat stuff there like blurcachetools.

5

this issue could be solved by saving subframe snapshots as well and rendering ‘real’ motion blur, but this solution will be very expensive render time and space wise.
there are a couple of compositing plugins that can bypass this issue by creating fake motion blur.