Colored mesh doesn't cast shadows over itself

edion86 · September 29, 2015, 10:01am

Well, title is quite specific. As you can see there are no shadows over the colored mesh (is coming from grasshopper, with colors related to its vertices).
The render is with standard rhino render, sun and skylight ON.

BrianJ · September 29, 2015, 2:09pm

I believe this is due to the color being RGB values baked into the verts of the mesh versus a texture map. Post the mesh and I’ll see if I can figure out a tweak to get this to work.

edion86 · September 30, 2015, 9:36am

Hi Brian, here you have it, hope you can help.
I’ve found out that many renders engines won’t render this color-vertex-meshes. So, it’d be important that rhino could.

BUG COLOR SHADOW.3dm (156.5 KB)

BrianJ · September 30, 2015, 1:09pm

You can use the Brazil for Rhino render plugin which has a Vertex Colors Texture. If you assign one to the color channel of a material the vertex colors will be used and you’ll get self shadows. This will also work with the Neon plugin to render in the viewport if Brazil is the active render plugin.

edion86 · October 1, 2015, 1:35pm

Thanks Brian, I’ll try with neon since is free.
Also, one last question if you don’t mind. How can I delete the color information from the mesh?
Another opcion will always be render with the colors, and later a white mesh with shadows. Then photoshop.

Thanks for your help.
Diego

BrianJ · October 1, 2015, 3:46pm

Run the command ClearAllMeshes.

You can also add a “Single Color” texture map to the color channel of a material and then run ComputeVertexColors to replace the vertex colors with the color from the texture map.

clement · October 1, 2015, 4:56pm

@BrianJ _ClearAllMeshes does not affect meshes or their vertex colors.

@edion86 to delete mesh vertex colors, use _RebuildMesh

c.

BrianJ · October 1, 2015, 5:44pm

Odd, it did here using the file provided.

clement · October 1, 2015, 5:57pm

@BrianJ, me too. Did it using V5 x64 SR12, are you using a newer built ?

c.

BrianJ · October 1, 2015, 6:03pm

I see what it was now… an obscure Neon bug is the reason. If you’ve applied a basic material without a color map to a mesh with vertex colors and then look at it in Shaded mode, you see the vert colors not the material color. If you then ClearAllMeshes you’ll go to wireframe view and if you next immediately go into Neon mode the vertex colors are not seen in favor of the color of the material.

Your RebuildMesh workflow is much more reliable for removing vert colors. Thanks.