Problem with offset mesh

[mario.vergara]

Hello
I am trying to offset the attached mesh
I need to have an even distance of 18 mm inwards
For some reason this is not happening
You can see in the left side of the image that it gets deformed, i tried using gh (pufferfish and weaverbird) getting the same result
Could you please help?

mesh.3dm (116.4 KB)

[theoutside (Kyle Houchens)]

shrinkwrap it and use the offset function-

this video may help-

Rhino 8 windows- never fail shelling with Shrinkwrap (new feature!)

[mario.vergara]

Thank you Kyle
The problem with that method is that it makes the edges smoother
I need sharp edges
I do not understand why offset mesh can not keep an even distance
Best.

[AndersDeleuran]

@mario.vergara

You can see in the left side of the image that it gets deformed, i tried using gh (pufferfish and weaverbird) getting the same result
Could you please help?

You can try Daniel’s face-based mesh offsetting script over here:

Proper mesh offset

Here’s a mesh offset script example of what I was talking about earlier: meshoffset_options.gh (25.4 KB) You can choose between targeting at-least, at-most and average face-face distances, or standard vertex-vertex. [image] It’s easy to find meshes where no approaches work though, particularly with highly concave vertices, or non-planar quads, and I think trying to find a way of offsetting by simply moving vertices that works on all cases would be a recipe for frustration. I’m pretty sure …

[DanielPiker]

See the answer here illustrating why it is impossible to create a constant offset mesh by moving vertices:

Mesh Face Offset

It seems a bit unclear to me what you are actually after. You started by saying you want a face-face offset, and showed a diagram illustrating that you want constant face to face distances - ie parallel faces. What you show above is another way of computing one normal per vertex and moving the out along this, which does not solve this problem. To illustrate, take the example of trying to offset this red rectangular pyramid by moving the vertices. We take planes offset by unit distance from e…

[mario.vergara]

Thank you for your help!!!