I want to check to find any thin parts on a mesh. I figured I could do this by shooting rays in the reverse of their normals but it doesnt seem to be working right.

I tried first in vex but kept getting -1 value on hit distance. I then used a ray sop but the results look off.
https://i.imgur.com/YIHLnVP.png [i.imgur.com]
I made a group to color anything that hits under x amount red and it seems to almost work but if the results were right then the face on the other side should also be red.


I am not sure if I am going about this all wrong or if its just something simple.

Any chance you could post a simple scene file? (or maybe a portion of the mesh?) I can't quite make out the kind of mesh you are working on with screenshot.

You can try the following:

Create a VDB SDF from your mesh -> smooth it until the thin parts disappear -> use volumesample to mask thin parts.

Oh that is what you can use Volume Sampler, I need to look into the Volume Sampler node; what is the nuts and bolts of this node anyone care to explain ?

Breht - I assume you want to make a thin material ?

hey thank you all for responding.

I actually got it to work. I just needed to offset the normal.