Physically Based Rendering, 3rd Edition

3.6.2: Triangle intersection

The structure of the triangle shape’s Intersect() method follows the form of earlier intersection test methods: a geometric test is applied to determine if there is an intersection and, if so, further information is computed about the intersection to return in the given SurfaceInteraction.

〈Triangle Method Definitions〉 + ≡ bool Triangle::Intersect(const Ray &ray, Float *tHit,   SurfaceInteraction *isect, bool testAlphaTexture) const {

        〈Get triangle vertices in p0, p1, and p2 157〉

        〈Perform ray-triangle intersection test 158〉

        〈Compute triangle partial derivatives 164〉

        〈Compute error bounds for triangle intersection 227〉

        〈Interpolate (u, v) parametric coordinates and hit point 164〉

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