This seems to be because WorldPoint defaults to PaintNearestTriangleSurface() which then triggers an endless loop. To reproduce this, go to blender, use any basic object such as a sphere, and attempt to paint it. About halfway down the sphere, Unity will freeze for about a minute, multiple "Could not get point on surface" messages will appear, and then finally a StackOverflowException. I've also tested this on imported models on the asset store with similar results.
This seems to be because WorldPoint defaults to PaintNearestTriangleSurface() which then triggers an endless loop. To reproduce this, go to blender, use any basic object such as a sphere, and attempt to paint it. About halfway down the sphere, Unity will freeze for about a minute, multiple "Could not get point on surface" messages will appear, and then finally a StackOverflowException. I've also tested this on imported models on the asset store with similar results.