Surface From Points (SrfGrid), bug?

Hi there,

I seem to be encountering a possible bug - has anyone ran into this or do you have a fix?

I’m converting a normal quad mesh to a single surface using Surface From Points via vertices of the mesh. Although it’s working, I noticed it is removing the outermost isocurve on all 4 sides where there are clearly verts from the mesh (see example pictures attached).

Any thoughts would be greatly appreciated!

Hi @Alex_A,

If you bake the surface to Rhino, select it, and turn on its control points, what do you see?

— Dale

Thanks for the reply @dale

The control points are there on the baked surface, but the isocurves aren’t. It’s mainly an issue if I’m using the surface topology (paneling for example); the geometry becomes stretched on the outside edges

Hi @Alex_A,

Isocurves are really just eye candy.

From the Rhino Help:

An isoparametric curve (or isocurve) is a curve of constant u or v value on a surface. Rhino uses isocurves and surface edge curves to create a wireframe of the shape of a NURBS surface. By default isocurves are drawn at knot locations. If the surface is a single knot-span surface like a simple rectangular plane, isocurves are drawn also in the middle of the surface.

If you want to increase the density, for example, just select the surface in Rhino and from the Properties panel and adjust.


You can extract isocurves from any location on a surface using the ExtractIsocurve command. Grasshopper has an Iso Curve component you might find useful.

– Dale

Why does the topology get warped/stretched at the edges then?

Totally appreciate what you’re saying. Essentially I’m trying to control the flow of geometry by warping a mesh, then convert it to a surface that maintains that flow, but without those stretched edges that seem to happen when using SrfGrid (see attached example).