247 lines
8.8 KiB
C++
247 lines
8.8 KiB
C++
// Copyright 2009-2020 Intel Corporation
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// SPDX-License-Identifier: Apache-2.0
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#pragma once
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#include "triangle.h"
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#include "trianglev.h"
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#include "trianglev_mb.h"
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#include "intersector_epilog.h"
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/*! Modified Pluecker ray/triangle intersector. The test first shifts
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* the ray origin into the origin of the coordinate system and then
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* uses Pluecker coordinates for the intersection. Due to the shift,
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* the Pluecker coordinate calculation simplifies and the tests get
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* numerically stable. The edge equations are watertight along the
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* edge for neighboring triangles. */
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namespace embree
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{
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namespace isa
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{
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template<int M, typename UVMapper>
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struct PlueckerHitM
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{
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__forceinline PlueckerHitM(const vfloat<M>& U, const vfloat<M>& V, const vfloat<M>& UVW, const vfloat<M>& t, const Vec3vf<M>& Ng, const UVMapper& mapUV)
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: U(U), V(V), UVW(UVW), mapUV(mapUV), vt(t), vNg(Ng) {}
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__forceinline void finalize()
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{
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const vbool<M> invalid = abs(UVW) < min_rcp_input;
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const vfloat<M> rcpUVW = select(invalid,vfloat<M>(0.0f),rcp(UVW));
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vu = U * rcpUVW;
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vv = V * rcpUVW;
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mapUV(vu,vv);
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}
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__forceinline Vec2f uv (const size_t i) const { return Vec2f(vu[i],vv[i]); }
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__forceinline float t (const size_t i) const { return vt[i]; }
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__forceinline Vec3fa Ng(const size_t i) const { return Vec3fa(vNg.x[i],vNg.y[i],vNg.z[i]); }
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private:
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const vfloat<M> U;
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const vfloat<M> V;
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const vfloat<M> UVW;
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const UVMapper& mapUV;
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public:
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vfloat<M> vu;
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vfloat<M> vv;
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vfloat<M> vt;
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Vec3vf<M> vNg;
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};
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template<int M>
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struct PlueckerIntersector1
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{
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__forceinline PlueckerIntersector1() {}
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__forceinline PlueckerIntersector1(const Ray& ray, const void* ptr) {}
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template<typename UVMapper, typename Epilog>
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__forceinline bool intersect(Ray& ray,
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const Vec3vf<M>& tri_v0,
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const Vec3vf<M>& tri_v1,
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const Vec3vf<M>& tri_v2,
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const UVMapper& mapUV,
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const Epilog& epilog) const
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{
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/* calculate vertices relative to ray origin */
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const Vec3vf<M> O = Vec3vf<M>((Vec3fa)ray.org);
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const Vec3vf<M> D = Vec3vf<M>((Vec3fa)ray.dir);
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const Vec3vf<M> v0 = tri_v0-O;
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const Vec3vf<M> v1 = tri_v1-O;
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const Vec3vf<M> v2 = tri_v2-O;
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/* calculate triangle edges */
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const Vec3vf<M> e0 = v2-v0;
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const Vec3vf<M> e1 = v0-v1;
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const Vec3vf<M> e2 = v1-v2;
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/* perform edge tests */
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const vfloat<M> U = dot(cross(e0,v2+v0),D);
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const vfloat<M> V = dot(cross(e1,v0+v1),D);
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const vfloat<M> W = dot(cross(e2,v1+v2),D);
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const vfloat<M> UVW = U+V+W;
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const vfloat<M> eps = float(ulp)*abs(UVW);
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#if defined(EMBREE_BACKFACE_CULLING)
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vbool<M> valid = max(U,V,W) <= eps;
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#else
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vbool<M> valid = (min(U,V,W) >= -eps) | (max(U,V,W) <= eps);
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#endif
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if (unlikely(none(valid))) return false;
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/* calculate geometry normal and denominator */
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const Vec3vf<M> Ng = stable_triangle_normal(e0,e1,e2);
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const vfloat<M> den = twice(dot(Ng,D));
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/* perform depth test */
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const vfloat<M> T = twice(dot(v0,Ng));
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const vfloat<M> t = rcp(den)*T;
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valid &= vfloat<M>(ray.tnear()) <= t & t <= vfloat<M>(ray.tfar);
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valid &= den != vfloat<M>(zero);
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if (unlikely(none(valid))) return false;
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/* update hit information */
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PlueckerHitM<M,UVMapper> hit(U,V,UVW,t,Ng,mapUV);
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return epilog(valid,hit);
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}
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};
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template<int K, typename UVMapper>
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struct PlueckerHitK
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{
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__forceinline PlueckerHitK(const vfloat<K>& U, const vfloat<K>& V, const vfloat<K>& UVW, const vfloat<K>& t, const Vec3vf<K>& Ng, const UVMapper& mapUV)
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: U(U), V(V), UVW(UVW), t(t), Ng(Ng), mapUV(mapUV) {}
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__forceinline std::tuple<vfloat<K>,vfloat<K>,vfloat<K>,Vec3vf<K>> operator() () const
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{
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const vbool<K> invalid = abs(UVW) < min_rcp_input;
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const vfloat<K> rcpUVW = select(invalid,vfloat<K>(0.0f),rcp(UVW));
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vfloat<K> u = U * rcpUVW;
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vfloat<K> v = V * rcpUVW;
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mapUV(u,v);
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return std::make_tuple(u,v,t,Ng);
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}
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private:
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const vfloat<K> U;
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const vfloat<K> V;
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const vfloat<K> UVW;
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const vfloat<K> t;
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const Vec3vf<K> Ng;
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const UVMapper& mapUV;
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};
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template<int M, int K>
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struct PlueckerIntersectorK
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{
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__forceinline PlueckerIntersectorK(const vbool<K>& valid, const RayK<K>& ray) {}
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/*! Intersects K rays with one of M triangles. */
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template<typename UVMapper, typename Epilog>
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__forceinline vbool<K> intersectK(const vbool<K>& valid0,
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RayK<K>& ray,
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const Vec3vf<K>& tri_v0,
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const Vec3vf<K>& tri_v1,
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const Vec3vf<K>& tri_v2,
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const UVMapper& mapUV,
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const Epilog& epilog) const
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{
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/* calculate vertices relative to ray origin */
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vbool<K> valid = valid0;
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const Vec3vf<K> O = ray.org;
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const Vec3vf<K> D = ray.dir;
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const Vec3vf<K> v0 = tri_v0-O;
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const Vec3vf<K> v1 = tri_v1-O;
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const Vec3vf<K> v2 = tri_v2-O;
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/* calculate triangle edges */
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const Vec3vf<K> e0 = v2-v0;
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const Vec3vf<K> e1 = v0-v1;
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const Vec3vf<K> e2 = v1-v2;
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/* perform edge tests */
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const vfloat<K> U = dot(Vec3vf<K>(cross(e0,v2+v0)),D);
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const vfloat<K> V = dot(Vec3vf<K>(cross(e1,v0+v1)),D);
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const vfloat<K> W = dot(Vec3vf<K>(cross(e2,v1+v2)),D);
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const vfloat<K> UVW = U+V+W;
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const vfloat<K> eps = float(ulp)*abs(UVW);
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#if defined(EMBREE_BACKFACE_CULLING)
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valid &= max(U,V,W) <= eps;
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#else
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valid &= (min(U,V,W) >= -eps) | (max(U,V,W) <= eps);
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#endif
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if (unlikely(none(valid))) return false;
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/* calculate geometry normal and denominator */
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const Vec3vf<K> Ng = stable_triangle_normal(e0,e1,e2);
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const vfloat<K> den = twice(dot(Vec3vf<K>(Ng),D));
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/* perform depth test */
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const vfloat<K> T = twice(dot(v0,Vec3vf<K>(Ng)));
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const vfloat<K> t = rcp(den)*T;
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valid &= ray.tnear() <= t & t <= ray.tfar;
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valid &= den != vfloat<K>(zero);
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if (unlikely(none(valid))) return false;
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/* calculate hit information */
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PlueckerHitK<K,UVMapper> hit(U,V,UVW,t,Ng,mapUV);
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return epilog(valid,hit);
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}
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/*! Intersect k'th ray from ray packet of size K with M triangles. */
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template<typename UVMapper, typename Epilog>
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__forceinline bool intersect(RayK<K>& ray, size_t k,
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const Vec3vf<M>& tri_v0,
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const Vec3vf<M>& tri_v1,
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const Vec3vf<M>& tri_v2,
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const UVMapper& mapUV,
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const Epilog& epilog) const
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{
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/* calculate vertices relative to ray origin */
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const Vec3vf<M> O = broadcast<vfloat<M>>(ray.org,k);
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const Vec3vf<M> D = broadcast<vfloat<M>>(ray.dir,k);
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const Vec3vf<M> v0 = tri_v0-O;
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const Vec3vf<M> v1 = tri_v1-O;
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const Vec3vf<M> v2 = tri_v2-O;
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/* calculate triangle edges */
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const Vec3vf<M> e0 = v2-v0;
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const Vec3vf<M> e1 = v0-v1;
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const Vec3vf<M> e2 = v1-v2;
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/* perform edge tests */
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const vfloat<M> U = dot(cross(e0,v2+v0),D);
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const vfloat<M> V = dot(cross(e1,v0+v1),D);
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const vfloat<M> W = dot(cross(e2,v1+v2),D);
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const vfloat<M> UVW = U+V+W;
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const vfloat<M> eps = float(ulp)*abs(UVW);
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#if defined(EMBREE_BACKFACE_CULLING)
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vbool<M> valid = max(U,V,W) <= eps;
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#else
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vbool<M> valid = (min(U,V,W) >= -eps) | (max(U,V,W) <= eps);
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#endif
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if (unlikely(none(valid))) return false;
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/* calculate geometry normal and denominator */
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const Vec3vf<M> Ng = stable_triangle_normal(e0,e1,e2);
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const vfloat<M> den = twice(dot(Ng,D));
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/* perform depth test */
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const vfloat<M> T = twice(dot(v0,Ng));
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const vfloat<M> t = rcp(den)*T;
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valid &= vfloat<M>(ray.tnear()[k]) <= t & t <= vfloat<M>(ray.tfar[k]);
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if (unlikely(none(valid))) return false;
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/* avoid division by 0 */
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valid &= den != vfloat<M>(zero);
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if (unlikely(none(valid))) return false;
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/* update hit information */
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PlueckerHitM<M,UVMapper> hit(U,V,UVW,t,Ng,mapUV);
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return epilog(valid,hit);
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}
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};
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}
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}
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