Flattening almost flat non-planer facets

[alan (Dr Alan Van Drie)]

Unless I want a zillion triangular facets from a CAD STL import slowing down my simulation, I need to rebuild the model from scratch in molflow using the STL file as a template. Surfaces, composed of many triangles that are almost all flat to form the bigger facet that I want to make, but not flat enough for molflow’s higher precision. So what I do is 1) select the vertices to make a new bigger facet, which is non-planer. 2) to make it planer I rotate the model to place that facet axis plane. After that I can then set the perpendicular coordinate of its vertices the same now making it planer. I then rotate the model back. This is a PAIN to do. It would be nice to have a feature that could flatten without having to rotate the model. Maybe…

1. Take an average of the vertices of a non-planer facet to define the flat plane
2. Take the normal and two vertices of a non-planer facet to define the flat plane
3. Take three vertices of a non-planer facet to define the flat plane

[maarton (Marton Ady)]

This can already be achieved with the “Project” command, as in this tutorial, page 12:

iuvsta20_handout.pdf

Exactly as you suggest, you can refer to the plane with 3 vertices (most accurate), or take the plane of one of the small triangles (acceptable accuracy).

[alan (Dr Alan Van Drie)]

I was thinking the same thing, but didn’t try yet. It’s still and extra step of creating a facet from three vertices to project onto though.

[maarton (Marton Ady)]

You don’t have to create a temporary facet!

For projecting facets, use this option:

For projecting vertices, use the “get from 3 sel. vertices” button: