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path: root/intern/cycles/kernel/kernel_subsurface.h
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-rw-r--r--intern/cycles/kernel/kernel_subsurface.h165
1 files changed, 111 insertions, 54 deletions
diff --git a/intern/cycles/kernel/kernel_subsurface.h b/intern/cycles/kernel/kernel_subsurface.h
index 2da060c32a2..705b57ba6ff 100644
--- a/intern/cycles/kernel/kernel_subsurface.h
+++ b/intern/cycles/kernel/kernel_subsurface.h
@@ -16,7 +16,12 @@
CCL_NAMESPACE_BEGIN
-/* NEW BSSRDF: See "BSSRDF Importance Sampling", SIGGRAPH 2013 */
+/* BSSRDF using disk based importance sampling.
+ *
+ * BSSRDF Importance Sampling, SIGGRAPH 2013
+ * http://library.imageworks.com/pdfs/imageworks-library-BSSRDF-sampling.pdf
+ *
+ */
/* TODO:
* - test using power heuristic for combing bssrdfs
@@ -101,8 +106,6 @@ ccl_device float3 subsurface_scatter_eval(ShaderData *sd, ShaderClosure *sc, flo
float sample_weight_inv = 1.0f/sample_weight_sum;
- //printf("num closures %d\n", sd->num_closure);
-
for(int i = 0; i < sd->num_closure; i++) {
sc = &sd->closure[i];
@@ -179,19 +182,24 @@ ccl_device float3 subsurface_color_pow(float3 color, float exponent)
return color;
}
-ccl_device void subsurface_color_bump_blur(KernelGlobals *kg, ShaderData *out_sd, ShaderData *in_sd, int state_flag, float3 *eval, float3 *N)
+ccl_device void subsurface_color_bump_blur(KernelGlobals *kg,
+ ShaderData *sd,
+ PathState *state,
+ int state_flag,
+ float3 *eval,
+ float3 *N)
{
/* average color and texture blur at outgoing point */
float texture_blur;
- float3 out_color = shader_bssrdf_sum(out_sd, NULL, &texture_blur);
+ float3 out_color = shader_bssrdf_sum(sd, NULL, &texture_blur);
/* do we have bump mapping? */
- bool bump = (out_sd->flag & SD_HAS_BSSRDF_BUMP) != 0;
+ bool bump = (sd->flag & SD_HAS_BSSRDF_BUMP) != 0;
if(bump || texture_blur > 0.0f) {
/* average color and normal at incoming point */
- shader_eval_surface(kg, in_sd, 0.0f, state_flag, SHADER_CONTEXT_SSS);
- float3 in_color = shader_bssrdf_sum(in_sd, (bump)? N: NULL, NULL);
+ shader_eval_surface(kg, sd, state, 0.0f, state_flag, SHADER_CONTEXT_SSS);
+ float3 in_color = shader_bssrdf_sum(sd, (bump)? N: NULL, NULL);
/* we simply divide out the average color and multiply with the average
* of the other one. we could try to do this per closure but it's quite
@@ -206,14 +214,23 @@ ccl_device void subsurface_color_bump_blur(KernelGlobals *kg, ShaderData *out_sd
}
}
-/* subsurface scattering step, from a point on the surface to other nearby points on the same object */
-ccl_device int subsurface_scatter_multi_step(KernelGlobals *kg, ShaderData *sd, ShaderData bssrdf_sd[BSSRDF_MAX_HITS],
- int state_flag, ShaderClosure *sc, uint *lcg_state, float disk_u, float disk_v, bool all)
+/* Subsurface scattering step, from a point on the surface to other
+ * nearby points on the same object.
+ */
+ccl_device int subsurface_scatter_multi_intersect(
+ KernelGlobals *kg,
+ SubsurfaceIntersection* ss_isect,
+ ShaderData *sd,
+ ShaderClosure *sc,
+ uint *lcg_state,
+ float disk_u,
+ float disk_v,
+ bool all)
{
/* pick random axis in local frame and point on disk */
float3 disk_N, disk_T, disk_B;
float pick_pdf_N, pick_pdf_T, pick_pdf_B;
-
+
disk_N = sd->Ng;
make_orthonormals(disk_N, &disk_T, &disk_B);
@@ -259,70 +276,110 @@ ccl_device int subsurface_scatter_multi_step(KernelGlobals *kg, ShaderData *sd,
float3 disk_P = (disk_r*cosf(phi)) * disk_T + (disk_r*sinf(phi)) * disk_B;
/* create ray */
- Ray ray;
- ray.P = sd->P + disk_N*disk_height + disk_P;
- ray.D = -disk_N;
- ray.t = 2.0f*disk_height;
- ray.dP = sd->dP;
- ray.dD = differential3_zero();
- ray.time = sd->time;
+ Ray *ray = &ss_isect->ray;
+ ray->P = sd->P + disk_N*disk_height + disk_P;
+ ray->D = -disk_N;
+ ray->t = 2.0f*disk_height;
+ ray->dP = sd->dP;
+ ray->dD = differential3_zero();
+ ray->time = sd->time;
/* intersect with the same object. if multiple intersections are found it
* will use at most BSSRDF_MAX_HITS hits, a random subset of all hits */
- Intersection isect[BSSRDF_MAX_HITS];
- uint num_hits = scene_intersect_subsurface(kg, &ray, isect, sd->object, lcg_state, BSSRDF_MAX_HITS);
-
- /* evaluate bssrdf */
- float3 eval = make_float3(0.0f, 0.0f, 0.0f);
- int num_eval_hits = min(num_hits, BSSRDF_MAX_HITS);
+ scene_intersect_subsurface(kg,
+ ray,
+ ss_isect,
+ sd->object,
+ lcg_state,
+ BSSRDF_MAX_HITS);
+ int num_eval_hits = min(ss_isect->num_hits, BSSRDF_MAX_HITS);
for(int hit = 0; hit < num_eval_hits; hit++) {
- ShaderData *bsd = &bssrdf_sd[hit];
+ /* Quickly retrieve P and Ng without setting up ShaderData. */
+ float3 hit_P;
+ if(ccl_fetch(sd, type) & PRIMITIVE_TRIANGLE) {
+ hit_P = triangle_refine_subsurface(kg,
+ sd,
+ &ss_isect->hits[hit],
+ ray);
+ }
+#ifdef __OBJECT_MOTION__
+ else if(ccl_fetch(sd, type) & PRIMITIVE_MOTION_TRIANGLE) {
+ float3 verts[3];
+ motion_triangle_vertices(
+ kg,
+ ccl_fetch(sd, object),
+ kernel_tex_fetch(__prim_index, ss_isect->hits[hit].prim),
+ ccl_fetch(sd, time),
+ verts);
+ hit_P = motion_triangle_refine_subsurface(kg,
+ sd,
+ &ss_isect->hits[hit],
+ ray,
+ verts);
+ }
+#endif /* __OBJECT_MOTION__ */
- /* setup new shading point */
- *bsd = *sd;
- shader_setup_from_subsurface(kg, bsd, &isect[hit], &ray);
+ float3 hit_Ng = ss_isect->Ng[hit];
+ if(ss_isect->hits[hit].object != OBJECT_NONE) {
+ object_normal_transform(kg, sd, &hit_Ng);
+ }
/* probability densities for local frame axes */
- float pdf_N = pick_pdf_N * fabsf(dot(disk_N, bsd->Ng));
- float pdf_T = pick_pdf_T * fabsf(dot(disk_T, bsd->Ng));
- float pdf_B = pick_pdf_B * fabsf(dot(disk_B, bsd->Ng));
-
+ float pdf_N = pick_pdf_N * fabsf(dot(disk_N, hit_Ng));
+ float pdf_T = pick_pdf_T * fabsf(dot(disk_T, hit_Ng));
+ float pdf_B = pick_pdf_B * fabsf(dot(disk_B, hit_Ng));
+
/* multiple importance sample between 3 axes, power heuristic
* found to be slightly better than balance heuristic */
float mis_weight = power_heuristic_3(pdf_N, pdf_T, pdf_B);
/* real distance to sampled point */
- float r = len(bsd->P - sd->P);
+ float r = len(hit_P - sd->P);
/* evaluate */
float w = mis_weight / pdf_N;
- if(num_hits > BSSRDF_MAX_HITS)
- w *= num_hits/(float)BSSRDF_MAX_HITS;
- eval = subsurface_scatter_eval(bsd, sc, disk_r, r, all) * w;
+ if(ss_isect->num_hits > BSSRDF_MAX_HITS)
+ w *= ss_isect->num_hits/(float)BSSRDF_MAX_HITS;
+ float3 eval = subsurface_scatter_eval(sd, sc, disk_r, r, all) * w;
- /* optionally blur colors and bump mapping */
- float3 N = bsd->N;
- subsurface_color_bump_blur(kg, sd, bsd, state_flag, &eval, &N);
-
- /* setup diffuse bsdf */
- subsurface_scatter_setup_diffuse_bsdf(bsd, eval, true, N);
+ ss_isect->weight[hit] = eval;
}
return num_eval_hits;
}
+ccl_device void subsurface_scatter_multi_setup(KernelGlobals *kg,
+ SubsurfaceIntersection* ss_isect,
+ int hit,
+ ShaderData *sd,
+ PathState *state,
+ int state_flag,
+ ShaderClosure *sc,
+ bool all)
+{
+ /* Setup new shading point. */
+ shader_setup_from_subsurface(kg, sd, &ss_isect->hits[hit], &ss_isect->ray);
+
+ /* Optionally blur colors and bump mapping. */
+ float3 weight = ss_isect->weight[hit];
+ float3 N = sd->N;
+ subsurface_color_bump_blur(kg, sd, state, state_flag, &weight, &N);
+
+ /* Setup diffuse BSDF. */
+ subsurface_scatter_setup_diffuse_bsdf(sd, weight, true, N);
+}
+
/* subsurface scattering step, from a point on the surface to another nearby point on the same object */
-ccl_device void subsurface_scatter_step(KernelGlobals *kg, ShaderData *sd,
+ccl_device void subsurface_scatter_step(KernelGlobals *kg, ShaderData *sd, PathState *state,
int state_flag, ShaderClosure *sc, uint *lcg_state, float disk_u, float disk_v, bool all)
{
float3 eval = make_float3(0.0f, 0.0f, 0.0f);
- uint num_hits = 0;
/* pick random axis in local frame and point on disk */
float3 disk_N, disk_T, disk_B;
float pick_pdf_N, pick_pdf_T, pick_pdf_B;
-
+
disk_N = sd->Ng;
make_orthonormals(disk_N, &disk_T, &disk_B);
@@ -368,21 +425,21 @@ ccl_device void subsurface_scatter_step(KernelGlobals *kg, ShaderData *sd,
/* intersect with the same object. if multiple intersections are
* found it will randomly pick one of them */
- Intersection isect;
- num_hits = scene_intersect_subsurface(kg, &ray, &isect, sd->object, lcg_state, 1);
+ SubsurfaceIntersection ss_isect;
+ scene_intersect_subsurface(kg, &ray, &ss_isect, sd->object, lcg_state, 1);
/* evaluate bssrdf */
- if(num_hits > 0) {
+ if(ss_isect.num_hits > 0) {
float3 origP = sd->P;
/* setup new shading point */
- shader_setup_from_subsurface(kg, sd, &isect, &ray);
+ shader_setup_from_subsurface(kg, sd, &ss_isect.hits[0], &ray);
/* probability densities for local frame axes */
float pdf_N = pick_pdf_N * fabsf(dot(disk_N, sd->Ng));
float pdf_T = pick_pdf_T * fabsf(dot(disk_T, sd->Ng));
float pdf_B = pick_pdf_B * fabsf(dot(disk_B, sd->Ng));
-
+
/* multiple importance sample between 3 axes, power heuristic
* found to be slightly better than balance heuristic */
float mis_weight = power_heuristic_3(pdf_N, pdf_T, pdf_B);
@@ -391,16 +448,16 @@ ccl_device void subsurface_scatter_step(KernelGlobals *kg, ShaderData *sd,
float r = len(sd->P - origP);
/* evaluate */
- float w = (mis_weight * num_hits) / pdf_N;
+ float w = (mis_weight * ss_isect.num_hits) / pdf_N;
eval = subsurface_scatter_eval(sd, sc, disk_r, r, all) * w;
}
/* optionally blur colors and bump mapping */
float3 N = sd->N;
- subsurface_color_bump_blur(kg, sd, sd, state_flag, &eval, &N);
+ subsurface_color_bump_blur(kg, sd, state, state_flag, &eval, &N);
/* setup diffuse bsdf */
- subsurface_scatter_setup_diffuse_bsdf(sd, eval, (num_hits > 0), N);
+ subsurface_scatter_setup_diffuse_bsdf(sd, eval, (ss_isect.num_hits > 0), N);
}
CCL_NAMESPACE_END
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-18 10:45:46 +0300