Getting started with Pivot Painter and 3ds Max

Development Rendering
1

Hello! I am trying to follow some guides on how to use pivot painter to get some realistic grass physics going, but I am quite stuck. Most guides just say “just do X” without explaining the step, and I’m having a hard time figuring out the proper workflow.

Currently, I have a mesh of a tuft of grass (no hierarchy since they are all independent). I run the script, split the faces into separate elements, and export the mesh and the weightmaps (or whatever you call them). When I apply the maps to the instance of my material (following this guide: https://georgeokeeffegameart.wordpre…ealistic-wind/) I only get veeeeeeeeeeeeery slight movement. As if they are all attached with the exception of the most extreme vertices. I assume I have to manually paint the vertices using the Vertex Alpha Painter in the script to get more variation in the weighing.

But I cannot figure out what sort of values to start experimenting with, no matter what I try, everything gets completely weighed and I get no movement at all. Any ideas? Do any of you know of any decent walkthroughs of the workflow in 3ds max?

2

So I finally sort of got something sort of working, but I need help with what to look for.
I made 3ds max show the vertex alpha channel, so I could see what I was working with, and got the alpha painted as I would expect.

However I can’t get unreal engine to treat the weights quite right, it’s clearly stretching the middle parts more than the tops, despite them gradually having more weight towards the top in 3ds max. I even tried to manually paint them to ensure a smooth transition (0%, 10%, etc all the way to 100%). Yet vertices that should both be having 100% alphas are moving different amounts.
What am I missing?

Edit: I finally got it working! I disabled tangent normals in the material, tweaked the alpha further, reset Xform in max and reimported everything. It’s now moving perfectly!

3

Check the texture settings and change the filter to nearest and disable sRGB. If you still have more issues with this check the doc. here