I am currently trying to create a collision deformer/fake softbody collision with geometry nodes. I had looked at the really excellent deformers by Bradley Gerstmann and Xeofrios (and learnt a lot). Unfortunately, they don’t handle the actual collision the way I would like, so I tried to find my own way.
If you let an object collide with a simple surface, it works relatively well (although I would like to tweak the deformation a bit more).
Unfortunately, I often separate the XYZ axes in my approach, which makes it difficult to transfer it from a simple XY plane to more complex collision surfaces.
One idea was to find the nearest collision face for each vertex and use their normal as a base for rotation. Then I could continue to separate the XYZ axes, do everything as before and rotate the vertices back at the end.
As you can see this approach kinda works on even surfaces, but fails completely where two faces with different surface normals connect.
Currently I’m at a point where I don’t know if this whole rotate and rotate back approach is just plain stupid.
I would be really happy if someone smarter than me could take a look at the file I attached.
Except from that I’m happy to explain my approach a bit more detailed, I just didn’t want to make this post even longer.
(oh an by the way I plan to add a bit more advanced deformation and self collisions in the end, I just feel like I should find a way to reliably handle the collisions first)
CollisionDeformer3.blend (4.8 MB)
EDIT : here you can find a screenshot of the node tree
link to the full resolution screenshot
