I hear the term ‘cusp normals’ a lot.

Can someone explain to me what this is/what this means how I do it and why it is done?!

Thanks.

Basically you cusp your normals with a facetSop..if you are familiar with other packages it is like smoothing angle.

If you are not that familiar with modeling, it was allows edges to be soft or hard and to define the smoothing angle. The best way to see it clearly is create a box and render it…You will see that the surfaces have a gradated look rather than looking hard edged.

Now append a facetSop, turn on cusp and set the angle to 0 and make sure “post compute normals” is clicked on at the bottom. it should be clear what the difference is.

so the number represents the angle at which something will be shaded smooth or hard 0 all edges are hard. If you had a bevels this would make the bevels look faceted, so you would try another angle, like 22-45 or something.

Do not use Facet SOP to cusp normals. Facet SOP duplicates points to do that, which is a bad idea for almost all cases.
To have a cusp normals you need N attribute of vertex class, not points'. Use Vertex SOP->Cusp Normals instead.

Interesting, thanks. The way that I was taught was facet sop then an attribute Promote from points to vertices and fuse but I will adjust my workflow for sure.

You might also be interested in a workflow that details how to cusp normals and also use displacement with out tearing the hard edges. Due to using N for the cusp . Search on my site

Rob

circusmonkey
You might also be interested in a workflow that details how to cusp normals and also use displacement with out tearing the hard edges. Due to using N for the cusp . Search on my site

Rob

I am interested about this workflow for displacement without tearing apart.

And the VEX way of cusping vertices would be presumably this: