STL of quilt surfaces (curved surfaces)

[亜大_10628882]

Referring to CS80656, I want to convert a quilt surface to STL, but for curved surfaces (mirrors) it behaves like overlapping points. How can I avoid it?

[tbraxton]

I assume you are attempting to maintain optical surface topology in the conversion. STL format generates facets by design so if you need to represent curvature accurately, STL is not suitable for that.

If I misunderstand your query, please elaborate.

[亜大_10628882]

Thank you for your quick answer.
As you pointed out, accuracy is an issue when stl conversion of curved surfaces, but that is not a question in this case.
There is something I made a mistake with.
With the Shrinkwrap method of CS80656 this time, positive and negative surfaces can be created even in a flat surface(plane).
For example, for a plane of 36 triangles, create 72 triangles with different normal directions.
Is it possible to avoid this duplication?

[tbraxton]

This support article does not mention shrinkwrap.

https://www.ptc.com/en/support/article/CS80656 

I am not an expert on STL agorithms somaybe someone else has some advice regarding the normal vectors. I suspect there are 2 normals for each triangle to determine interior vs exterior side in closed shapes.