Can I union multiple transparent SCNShape objects?

Question

I'm adding multiple transparent SCNShape objects to an ARSCNSceneView scene.

• These shapes are based on user input and should overlap.
• They are all flat shapes made with UIBezierPath on the same plane
• Shapes has to be transparent, so the user can see the camera input behind

The problem is that overlapping shapes are very visible, and I'd like it to show as a single shape - the union of all shapes.

Failed approaches:

• Putting it under same node and use parent opacity.
• Merging the UIBezier paths.
• Blend modes
• Transparency modes
• Drawing using primitive triangles instead of UIBezierPath

Answer 1

You could have a look at VectorBoolean which is a swift library to deal with boolean operations like the union you are looking for. I haven't tried it myself but have heard some good things about it.