A file of a model is STL.
I want to get those faces which can be seen in a Top View.
This problem make me feel difficult.
Compute the angle between each face’s normal with the view direction (vector). If the angle is between 0 and 90 degrees, then the face should be visible.
Here is a sample of what I mentioned.
Hi ! dale. I am happy about your help. thanks!
It will happen this problem.
In addition, why is it slow when those faces which are selected are showed on the view ?
The mesh have a lot of faces. ( 200K~500K polygons)