Dear McNeel Team,
I’m trying the latest Rhino 9 WIP and using the Patch command. I’m unclear about the Molded option in the Domain settings. Could you explain what it does, how it handles 3D non-planar curves, and how it differs from Projected and Untrimmed options? Specifically, I’m curious about its 3D parameterization mapping and how it generates the trim domain.
Thank you,
Hi -
Just to make sure, did you review the information in the help file on this?
Domain
The domain option is used to create a trim domain on the surface that outlines the patch.Untrimmed
Creates an untrimmed surface. This option is only available when the input segments on the boundary can be merged into four smooth segments.Projected
Suitable for input objects that are more or less planar; this option is selected automatically if that is the case.Molded
Default for all other cases. This option creates the best trimming domain for curves that are less planar.
-wim
I’ve read this introduction, but I still don’t understand the principle behind the Molded option
The help file isn’t clear. When adding a constraint curve, the surface can only be properly trimmed if the constraint curve’s continuity is set to I (Internal) and the “Int” option in the Constraints Test Results turns green. I figured this out by accident after experimenting for two hours
hi @chenjiajin thanks for reporting.
RH-90137 Help for Patch: internal constraints
The documentation for this new feature states, “Projected: Suitable for input curves that are more or less planar.” However, my tests seem to show the opposite, which is confusing. I’m using the example provided by the developers
fillsrf-example-3.3dm (215.3 KB)
Hey, could you help me take a look at this? I’ve been tinkering with it all afternoon and just can’t figure it out. What’s the difference between a molder and a project? And how does a molder even work？thank you very much
I can’t explain the technicalities of how it works, for that you’ll have to wait for @menno to chime in.
This is a tricky corner. You could make it from an untrimmed patch instead.
This slightly modified example shows how:
fillsrf-example-adjusted.3dm (1.3 MB)
If you open that sample and double click the patch I made, you can see the settings I used to create it
Thank you so much, I’ve learned your document.
Does that mean that existing patch surfaces consist a history with the settings used to create them? Perhaps these are stored only on non-modified patches, so a slight manual edit of one of the control points will delete the settings?
Having a double-click-to-edit option for “Blend surface”, “Fillet” and the other surfacing tools would be handy.
The Molded option starts from the Projected option, in which the edge curves are projected to a plane that fits the curves the best. The location on the plane immediately gives the UV parameterization. When the curves together are more or less planar, the Projected option will be default.
In the Molded option, starting from the projected parameterization, the edge constraint weights are increased iteratively, and at each iteration the edge paramerization is improved w.r.t. the surface shape by closest point finding from the curves to the slightly bent surface. This procedure conceptually mimics molding of a flat metal plate into a mold, hence the name.
