I'm used to using the nori rendering engine and am trying to transform some code over to pbrt so I can create scenes with analytic spheres more easily. I'm trying to take a vector I've sampled from a hemisphere and transform it to the coordinate frame of the shading normal and am having trouble finding out how to do so cleanly. I want my code to look something like this:
scene.Intersection(ray,&isect);
Vector3f localDir = SampleUniformHemisphere();
Vector3f worldDir = isect.shadingFrame.toWorld(localDir);
Any advice on how I can do this?
