bool RayTesselatedSegmentPrimitive::Intersect(const Ray& ray, Intersection* intersection) {
Vec3f v0, v1;
_ResolveVertexAttrib(v0,v1,segments->pos);
float t,u, rayEpsilon;
bool hit = IntersectHairSegment(v0,v1,segments->radius,ray,&t,&u,&rayEpsilon);
if(hit) {
// intesection
intersection->rayEpsilon = rayEpsilon;
intersection->t = t;
intersection->dp.P = ray.Eval(t);
intersection->dp.uv = Vec2f(u,0);
if(segments->tangent.empty()) {
intersection->dp.Ng = segments->segmentTangent[idx];
intersection->dp.N = segments->segmentTangent[idx];
} else {
intersection->dp.Ng = ElementOperations::SegmentTangent(v0,v1);
intersection->dp.N = _InterpolateVertexAttrib(u,segments->tangent).GetNormalized();
}
intersection->dp.GenerateTuTv();
if(segments->uv.empty()) {
intersection->dp.st = intersection->dp.uv;
} else {
intersection->dp.st = _InterpolateVertexAttrib(u,segments->uv);
}
intersection->m = material;
}
return hit;
}
bool RayTesselatedTrianglePrimitive::Intersect(const Ray& ray, Intersection* intersection) {
Vec3f v0, v1, v2;
_ResolveVertexAttrib(v0,v1,v2,triangles->pos);
float t, b1, b2, rayEpsilon;
bool hit = IntersectTriangle(v0,v1,v2,ray, &t, &b1, &b2, &rayEpsilon);
if(hit) {
// geometry
intersection->t = t;
intersection->rayEpsilon = rayEpsilon;
intersection->dp.P = ray.Eval(t);
intersection->dp.uv = Vec2f(b1,b2);
if(triangles->normal.empty()) {
intersection->dp.Ng = triangles->faceNormal[idx];
intersection->dp.N = triangles->faceNormal[idx];
} else {
intersection->dp.Ng = ElementOperations::TriangleNormal(v0,v1,v2);
intersection->dp.N = _InterpolateVertexAttrib(b1,b2,triangles->normal).GetNormalized();
}
intersection->dp.GenerateTuTv();
// shading
if(triangles->uv.empty()) {
intersection->dp.st = intersection->dp.uv;
} else {
intersection->dp.st = _InterpolateVertexAttrib(b1,b2,triangles->uv);
}
// material
intersection->m = material;
}
return hit;
}
bool RayTesselatedSpherePrimitive::Intersect(const Ray& ray, Intersection* intersection) {
Vec3f p;
float r;
float rayEpsilon;
Matrix4d m;
Matrix4d mi;
_ResolveSphereAttrib(p,r,m,mi);
// xform the ray
Ray xformRay = ray;
xformRay.Transform(mi);
float t;
bool hit = IntersectSphere(p, r, xformRay, &t, &rayEpsilon);
if(hit) {
intersection->rayEpsilon = rayEpsilon;
intersection->t = t;
intersection->dp.P = xformRay.Eval(t);
intersection->dp.Ng = (intersection->dp.P - p).GetNormalized();
intersection->dp.N = intersection->dp.Ng;
intersection->dp.uv[0] = (atan2f(intersection->dp.N[0], intersection->dp.N[1]) + (float)PI) / (float)(2*PI);
intersection->dp.uv[1] = acosf(intersection->dp.N[2]) / (float)PI;
intersection->dp.GenerateTuTv();
intersection->dp.st = intersection->dp.uv;
intersection->m = material;
}
// xform back
if(hit) {
intersection->Transform(m);
}
return hit;
}
