inside vs outside of face edge

adamohern

If I query a face's edges, how do I figure out which side of the edge is inside (i.e. toward the face) and which is outside (away from the face)?

My initial thought was to extrude the edges normal to the face and work it out using the resultant face normals. Is there a better way?

ilya_baran

I think what you're asking for is a function that given a face and adjacent edge tells you whether the edge direction is clockwise or counterclockwise about the face nromal.

I don't expect extruding the sketch edge and using the normal to be too robust -- for the time being (until we have a proper test) for a planar face (which it sounds like you're working with), making a slight offset from a point in the middle of the edge in the (edge tangent) cross (face normal) direction and seeing if qContainsPoint filters out the face or not is likely to work better.

adamohern

Right, okay. That makes sense. I'll give that a try.