Edit Control Points with Locked Edge

Rhino Rhino for Windows
1

Hello,

I made a surface as a terrain model using patch. I’d like the boundary edge of the patch surface to remain fixed as I modify the control points making up the patch. When I modify the control points the surface splits away from the original boundary curves.

I tried untrimming and shrinking the trimmed surface, but I’m not able to make that work.

Is there an easy way to hold the trimmed patch boundary steady as I modify the patch control points?

Thanks for any suggestions.
Jeff

2

Hi Jeff - try making the patch with History recording on, and then modify the input objects’ points.

-Pascal

3

There is no easy way to “freeze” a trimmed boundary of a surface while moving surface control points.

The one exception is if the trimmed boundary coincides with a surface isocurve, and the entire trimmed surface lies on one side of the isocurve. In that situation Shrink the surface so the formerly trimmed boundary is an edge of the shrunk surface. Then the boundary will not move as long as the control points for that edge are not moved.

4

Hi Pascal,
I tried this but the patch surfaced edges continue to move. I suppose my wish list would include a way to hold a surface edge still while moving its interior about.

Thanks, Jeff

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