SketchUp soft flag?

1.Display :
when open .skp file , we get many rectangle faces. In fact , in SketchUp it is a continuous face. see picture [a_countiues _face and many_rectangle_faces.png]. which interactive selection is not very good

2.Modeling Data:
In SketchUp, all edges are line Edges, it treated arc edge as many line Edges and add soft flag to connected vertex;
A cylinder Face is treated as many rectangle plan Face , and add soft flag to inner Edges, a bit like seam Edge.
see picture [continuous_face_soft_vertex_and_edge.png]
Brep_Edge can add a soft flag: example use a int value, choose one bit to store the flag, also Brep_Vertex

Modeling Algorithm:
with soft flag we can treat Solid modeling to Polyhedron modeling with nearly no code modified.

It is Suitable for less accurate Modeling, and simulate a curve and surface


What are you trying to do with the SketchUp model once it’s in Rhino? Unless you absolutely need it (there are cases) I would import it as a mesh and not as planar surfaces. I would do that first and see if it get closer to what you need.

If it doesn’t help then please describe what you’re looking for in Rhino terms because I’m not familiar with the SketchUp terms you used.


Thanks for reply:
When import he SketchUp model in Rhino, I hope when mouse pick up a continuous face((with many sub triangles or quadrilaterals)), then the continuous face is highlight, rather than a triangle is highlight.

We try to use ngons for their faces, like the ends of a cylinder. You can use the command AddNgonsToMesh to combine additional planar sets that were more than one adjacent face in the SketchUp file. In Rhino we call edges that have unique vertex indexes for the faces that share the edge “unwelded”. You can use the command SelMeshPart to select adjacent faces up to unwelded edges.

The way edges on breps are in Rhino is very unlikely to change. That’s why I’m suggesting that you take the mesh route. While I don’t know what “soft flag” means in SketchUp I suspect it’s the analog of our “welded” edge. Where the face vertex indices for the faces that share the edge are the same.

I hope this helps.


1 Like

Deer Tim, Maybe I am not described clearly.
SketchUp soft Edge: Softening, Smoothing, and Hiding Geometry | SketchUp Help
Is Rhino has similar functions as above article ?

With regard to polysurfaces, Rhino does not have what you’re looking for. At least I’m not aware of any tools/settings like that. If I’m wrong hopefully someone will set me straight. There’s plenty of Rhino users much smarter than me.

I’ve mentioned above a few commands for meshes in Rhino that have some similar effects to what is described in your SketchUp doc. AddNgonsToMesh is similar to soften but it’s only applied to coplanar sets of faces. Weld will give you a smoothing effect but the edges will still be visible until you render. SelMeshPart will select adjacent faces to an initial face pick up to non welded edges. Did you actually try anything I mentioned? Try starting one of the commands and then push F1. That will take you to a help page where you’ll get a better description of what the commands do.

In the end though you need to consider that Rhino and SketchUp are 2 different apps. If you like the way SketchUp works, use SketchUp.


Hi @527266268,

We’ve moved your topic to the Rhino category so others experience in both Rhino and SketchUp can chime in.

– Dale

You’re not wrong, no.
There’s nothing in Rhino that will consider non-planar mesh faces to be a single surface.