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Cycles: Use utility function for SSS triangle intersection

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This effectively de-duplicates triangle intersection logic implemented
for both regular triangle and SSS triangle.
This commit is contained in:
Sergey Sharybin 2017-03-23 15:17:26 +01:00
parent a5b6742ed2
commit 2a5d7b5b1e
1 changed files with 20 additions and 116 deletions
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136
intern/cycles/kernel/geom/geom_triangle_intersect.h
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@ -102,129 +102,27 @@ ccl_device_inline void triangle_intersect_subsurface(
uint *lcg_state,
int max_hits)
{
const int kx = isect_precalc->kx;
const int ky = isect_precalc->ky;
const int kz = isect_precalc->kz;
const float Sx = isect_precalc->Sx;
const float Sy = isect_precalc->Sy;
const float Sz = isect_precalc->Sz;
/* Calculate vertices relative to ray origin. */
const uint tri_vindex = kernel_tex_fetch(__prim_tri_index, prim_addr);
#if defined(__KERNEL_AVX2__) && defined(__KERNEL_SSE__)
const ssef *verts = (ssef*)&kg->__prim_tri_verts.data[tri_vindex];
#else
const float4 tri_a = kernel_tex_fetch(__prim_tri_verts, tri_vindex+0),
tri_b = kernel_tex_fetch(__prim_tri_verts, tri_vindex+1),
tri_c = kernel_tex_fetch(__prim_tri_verts, tri_vindex+2);
#if defined(__KERNEL_AVX2__) && defined(__KERNEL_SSE__)
const avxf avxf_P(P.m128, P.m128);
const avxf tri_ab = kernel_tex_fetch_avxf(__prim_tri_verts, tri_vindex + 0);
const avxf tri_bc = kernel_tex_fetch_avxf(__prim_tri_verts, tri_vindex + 1);
const avxf AB = tri_ab - avxf_P;
const avxf BC = tri_bc - avxf_P;
const __m256i permuteMask = _mm256_set_epi32(0x3, kz, ky, kx, 0x3, kz, ky, kx);
const avxf AB_k = shuffle(AB, permuteMask);
const avxf BC_k = shuffle(BC, permuteMask);
/* Akz, Akz, Bkz, Bkz, Bkz, Bkz, Ckz, Ckz */
const avxf ABBC_kz = shuffle<2>(AB_k, BC_k);
/* Akx, Aky, Bkx, Bky, Bkx,Bky, Ckx, Cky */
const avxf ABBC_kxy = shuffle<0,1,0,1>(AB_k, BC_k);
const avxf Sxy(Sy, Sx, Sy, Sx);
/* Ax, Ay, Bx, By, Bx, By, Cx, Cy */
const avxf ABBC_xy = nmadd(ABBC_kz, Sxy, ABBC_kxy);
float ABBC_kz_array[8];
_mm256_storeu_ps((float*)&ABBC_kz_array, ABBC_kz);
const float A_kz = ABBC_kz_array[0];
const float B_kz = ABBC_kz_array[2];
const float C_kz = ABBC_kz_array[6];
/* By, Bx, Cy, Cx, By, Bx, Ay, Ax */
const avxf BCBA_yx = permute<3,2,7,6,3,2,1,0>(ABBC_xy);
const avxf negMask(0,0,0,0,0x80000000, 0x80000000, 0x80000000, 0x80000000);
/* W U V
* (AxBy-AyBx) (BxCy-ByCx) XX XX (BxBy-ByBx) (CxAy-CyAx) XX XX
*/
const avxf WUxxxxVxx_neg = _mm256_hsub_ps(ABBC_xy * BCBA_yx, negMask /* Dont care */);
const avxf WUVWnegWUVW = permute<0,1,5,0,0,1,5,0>(WUxxxxVxx_neg) ^ negMask;
/* Calculate scaled barycentric coordinates. */
float WUVW_array[4];
_mm_storeu_ps((float*)&WUVW_array, _mm256_castps256_ps128 (WUVWnegWUVW));
const float W = WUVW_array[0];
const float U = WUVW_array[1];
const float V = WUVW_array[2];
const int WUVW_mask = 0x7 & _mm256_movemask_ps(WUVWnegWUVW);
const int WUVW_zero = 0x7 & _mm256_movemask_ps(_mm256_cmp_ps(WUVWnegWUVW,
_mm256_setzero_ps(), 0));
if(!((WUVW_mask == 7) || (WUVW_mask == 0)) && ((WUVW_mask | WUVW_zero) != 7)) {
return;
}
#else
const float3 A = make_float3(tri_a.x - P.x, tri_a.y - P.y, tri_a.z - P.z);
const float3 B = make_float3(tri_b.x - P.x, tri_b.y - P.y, tri_b.z - P.z);
const float3 C = make_float3(tri_c.x - P.x, tri_c.y - P.y, tri_c.z - P.z);
const float A_kx = IDX(A, kx), A_ky = IDX(A, ky), A_kz = IDX(A, kz);
const float B_kx = IDX(B, kx), B_ky = IDX(B, ky), B_kz = IDX(B, kz);
const float C_kx = IDX(C, kx), C_ky = IDX(C, ky), C_kz = IDX(C, kz);
/* Perform shear and scale of vertices. */
const float Ax = A_kx - Sx * A_kz;
const float Ay = A_ky - Sy * A_kz;
const float Bx = B_kx - Sx * B_kz;
const float By = B_ky - Sy * B_kz;
const float Cx = C_kx - Sx * C_kz;
const float Cy = C_ky - Sy * C_kz;
/* Calculate scaled barycentric coordinates. */
float U = Cx * By - Cy * Bx;
float V = Ax * Cy - Ay * Cx;
float W = Bx * Ay - By * Ax;
if((U < 0.0f || V < 0.0f || W < 0.0f) &&
(U > 0.0f || V > 0.0f || W > 0.0f))
{
return;
}
const float3 verts[3] = {float4_to_float3(tri_a),
float4_to_float3(tri_b),
float4_to_float3(tri_c)};
#endif
/* Calculate determinant. */
float det = U + V + W;
if(UNLIKELY(det == 0.0f)) {
return;
}
/* Calculate scaled z−coordinates of vertices and use them to calculate
* the hit distance.
*/
const int sign_det = (__float_as_int(det) & 0x80000000);
const float T = (U * A_kz + V * B_kz + W * C_kz) * Sz;
const float sign_T = xor_signmask(T, sign_det);
if((sign_T < 0.0f) ||
(sign_T > tmax * xor_signmask(det, sign_det)))
float t, u, v;
if(!ray_triangle_intersect(isect_precalc,
P, tmax,
verts,
&u, &v, &t))
{
return;
}
/* Normalize U, V, W, and T. */
const float inv_det = 1.0f / det;
const float t = T * inv_det;
for(int i = min(max_hits, ss_isect->num_hits) - 1; i >= 0; --i) {
if(ss_isect->hits[i].t == t) {
return;
@ -251,11 +149,17 @@ ccl_device_inline void triangle_intersect_subsurface(
isect->prim = prim_addr;
isect->object = object;
isect->type = PRIMITIVE_TRIANGLE;
isect->u = U * inv_det;
isect->v = V * inv_det;
isect->u = u;
isect->v = v;
isect->t = t;
/* Record geometric normal. */
/* TODO(sergey): Check whether it's faster to re-use ssef verts. */
#if defined(__KERNEL_AVX2__) && defined(__KERNEL_SSE__)
const float4 tri_a = kernel_tex_fetch(__prim_tri_verts, tri_vindex+0),
tri_b = kernel_tex_fetch(__prim_tri_verts, tri_vindex+1),
tri_c = kernel_tex_fetch(__prim_tri_verts, tri_vindex+2);
#endif
/* TODO(sergey): Use float4_to_float3() on just an edges. */
const float3 v0 = float4_to_float3(tri_a);
const float3 v1 = float4_to_float3(tri_b);