Hi,

I'm starting to learn Houdini, and trying to play a little bit with voronoi fractures.

I'm having a little problem with the generated poly at edge.

I'm creating a poly box and scattering points, then fracturing. Up until that it works fine, but on the fractured object appears some “shading artefact” (will call them that lacking a better description).

It's already seen in the viewport, no need to render, but it's of course on the renders also…

See attached jpg.

Beveling the box before fracturing reduce but not make the problem disappear.

I'm surely missing something here, but it's beyond my current Houdini knowledge.

Please help

Add a Vertex SOP and change Keep Normal to Cusp Normal. Then adjust the angle to control the vertex face normals where they are shared and where they are aligned to the primitive to get hard edges.

Does that help?

It works, thanks

in simulation color, inside of each piece of fracture is black!
how can change color?
thank you.

NimaNolan
in simulation color, inside of each piece of fracture is black!
how can change color?
thank you.

Display your Primitive normals and make sure the primitives are facing outward to match the outside group primitives.

If not, reverse the inside primitive group.

jeff
Display your Primitive normals and make sure the primitives are facing outward to match the outside group primitives.

If not, reverse the inside primitive group.

can you attach an example?
thanks.