Say there’s a tri made of three vertices, A-B-C. I want to offset B by N mm from it’s current position on the X,Y plane. I want this translation to take place such that A-(Old B)-(New B) has the same angle as C-(Old B)-(New B). Or to put it another way, so that if A-B-C were a slice of cake, Old B-New B would cut it in half.
This isn’t especially difficult to code, just time consuming, and I figure anything I write will probably be less efficient than what’s already written. I’ve had a look through blender’s geometry mathutils, but I don’t understand the names of a lot of them. If anyone knows any of them which do some or all of this then I’d be grateful for having it pointed out.