Something like Line3d.ClipByPlane

[luithefirst]

I've found static bool Intersects(this Line3d line, Plane3d plane, out double t, out V3d p), but a more convenient method to directly clip a line (2d and 3d) would be nice. The only questions would be if the negative or positive side should be clipped. I would say we should follow how we have also defined our Hull3d data structure. There negative is "inside", so we would clip the positive side?

Polygons also have a ConvexClipped method: "Returns all parts of the polygon that are at the positive side of the plane" ... well, what do you think?