And the intersection test fails

V.3 RAY-TRIANGLE INTERSECTION USING BINARY RECURSIVE SUBDIVISION

edge overlaps the intersection point’s projection, then the line segment and the triangle do not intersect.

We now look at the span between these two edge points and do 1D comparisons in the M dimension. If the intersection point lies on the span between these two edge locations, then the intersection point is inside the triangle, and the intersection test succeeds; otherwise, it is

GRAPHICS GEMS II Edited by JAMES ARVO 260

Step 3: U, V Computation

If intersected triangles are assumed to have a canonical U, V mapping of 0, 0, 0, 1, and 1, 0 at the three vertices, as shown in Fig. 3, then the U, V values at the two edge points are available directly.