And when you've got the concepts, some fairly readable GPLed code is here: https://github.com/solvespace/solvespace/blob/master/src/srf/ratpoly.cpp https://git

And when you've got the concepts, some fairly readable GPLed code is here: https://github.com/solvespace/solvespace/blob/master/src/srf/ratpoly.cpp https://github.com/solvespace/solvespace/blob/master/src/srf... It used to culminate in a function for finding a point at the intersection of 3 rational Bezier surfaces, but we had to add something less exciting at the end.