(2019-12-16, 22:02)Lasse Deleuran Wrote: I had to deviate from the specification regarding the V-projection for spherical. Instead of having the plane P2 containing p1, p2 and a point along the normal of P1, P2 is computed using p and the projection from p onto P1.
Should the spec be updated, or are we all implementing this incorrectly?
I'm not sure I fully understand. I think perhaps the existing wording is ambiguous, but not necessarily wrong. P1 has an infinite number of normals. Unless I'm misremembering, the intent is to take one of those normals that originates along the line between p1 and p2, move along that normal some arbitrary distance, and use that point (along with p1 and p2) as the third point for P2. So, for example, add the normal vector for P1 to p1 to obtain the third point to construct P2.