[Bf-blender-cvs] [0df9b2c7151] master: Cycles: random walk subsurface scattering.
Brecht Van Lommel
noreply at git.blender.org
Fri Feb 9 20:12:00 CET 2018
Commit: 0df9b2c71517a98760a5e577f434d9d86e4e1910
Author: Brecht Van Lommel
Date: Sun Jan 21 14:04:22 2018 +0100
Branches: master
https://developer.blender.org/rB0df9b2c71517a98760a5e577f434d9d86e4e1910
Cycles: random walk subsurface scattering.
It is basically brute force volume scattering within the mesh, but part
of the SSS code for faster performance. The main difference with actual
volume scattering is that we assume the boundaries are diffuse and that
all lighting is coming through this boundary from outside the volume.
This gives much more accurate results for thin features and low density.
Some challenges remain however:
* Significantly more noisy than BSSRDF. Adding Dwivedi sampling may help
here, but it's unclear still how much it helps in real world cases.
* Due to this being a volumetric method, geometry like eyes or mouth can
darken the skin on the outside. We may be able to reduce this effect,
or users can compensate for it by reducing the scattering radius in
such areas.
* Sharp corners are quite bright. This matches actual volume rendering
and results in some other renderers, but maybe not so much real world
objects.
Differential Revision: https://developer.blender.org/D3054
===================================================================
M intern/cycles/blender/blender_shader.cpp
M intern/cycles/kernel/closure/bsdf.h
M intern/cycles/kernel/closure/bssrdf.h
M intern/cycles/kernel/closure/volume.h
M intern/cycles/kernel/geom/geom_motion_triangle_intersect.h
M intern/cycles/kernel/geom/geom_triangle_intersect.h
M intern/cycles/kernel/kernel_path.h
M intern/cycles/kernel/kernel_path_branched.h
M intern/cycles/kernel/kernel_path_subsurface.h
M intern/cycles/kernel/kernel_subsurface.h
M intern/cycles/kernel/kernel_types.h
M intern/cycles/kernel/kernel_volume.h
M intern/cycles/kernel/osl/osl_bssrdf.cpp
M intern/cycles/kernel/shaders/node_subsurface_scattering.osl
M intern/cycles/kernel/split/kernel_subsurface_scatter.h
M intern/cycles/kernel/svm/svm_closure.h
M intern/cycles/kernel/svm/svm_types.h
M intern/cycles/render/integrator.cpp
M intern/cycles/render/nodes.cpp
M intern/cycles/util/util_math_float3.h
M source/blender/makesdna/DNA_node_types.h
M source/blender/makesrna/intern/rna_nodetree.c
===================================================================
diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index ac1eba85dbb..d6f7a08431d 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -433,6 +433,9 @@ static ShaderNode *add_node(Scene *scene,
case BL::ShaderNodeSubsurfaceScattering::falloff_BURLEY:
subsurface->falloff = CLOSURE_BSSRDF_BURLEY_ID;
break;
+ case BL::ShaderNodeSubsurfaceScattering::falloff_RANDOM_WALK:
+ subsurface->falloff = CLOSURE_BSSRDF_RANDOM_WALK_ID;
+ break;
}
node = subsurface;
diff --git a/intern/cycles/kernel/closure/bsdf.h b/intern/cycles/kernel/closure/bsdf.h
index 6f0bdb3fa38..e3beff6675a 100644
--- a/intern/cycles/kernel/closure/bsdf.h
+++ b/intern/cycles/kernel/closure/bsdf.h
@@ -30,9 +30,7 @@
#include "kernel/closure/bsdf_principled_diffuse.h"
#include "kernel/closure/bsdf_principled_sheen.h"
#include "kernel/closure/bssrdf.h"
-#ifdef __VOLUME__
-# include "kernel/closure/volume.h"
-#endif
+#include "kernel/closure/volume.h"
CCL_NAMESPACE_BEGIN
diff --git a/intern/cycles/kernel/closure/bssrdf.h b/intern/cycles/kernel/closure/bssrdf.h
index c8f505e8418..790368ee888 100644
--- a/intern/cycles/kernel/closure/bssrdf.h
+++ b/intern/cycles/kernel/closure/bssrdf.h
@@ -408,7 +408,8 @@ ccl_device int bssrdf_setup(ShaderData *sd, Bssrdf *bssrdf, ClosureType type)
bssrdf->sharpness = saturate(bssrdf->sharpness);
if(type == CLOSURE_BSSRDF_BURLEY_ID ||
- type == CLOSURE_BSSRDF_PRINCIPLED_ID)
+ type == CLOSURE_BSSRDF_PRINCIPLED_ID ||
+ type == CLOSURE_BSSRDF_RANDOM_WALK_ID)
{
bssrdf_burley_setup(bssrdf);
}
diff --git a/intern/cycles/kernel/closure/volume.h b/intern/cycles/kernel/closure/volume.h
index 4bb5e680723..da791e9aa73 100644
--- a/intern/cycles/kernel/closure/volume.h
+++ b/intern/cycles/kernel/closure/volume.h
@@ -83,35 +83,45 @@ ccl_device float3 volume_henyey_greenstein_eval_phase(const ShaderClosure *sc, c
return make_float3(*pdf, *pdf, *pdf);
}
-ccl_device int volume_henyey_greenstein_sample(const ShaderClosure *sc, float3 I, float3 dIdx, float3 dIdy, float randu, float randv,
- float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
+ccl_device float3 henyey_greenstrein_sample(float3 D, float g, float randu, float randv, float *pdf)
{
- const HenyeyGreensteinVolume *volume = (const HenyeyGreensteinVolume*)sc;
- float g = volume->g;
- float cos_phi, sin_phi, cos_theta;
-
/* match pdf for small g */
- if(fabsf(g) < 1e-3f) {
+ float cos_theta;
+ bool isotropic = fabsf(g) < 1e-3f;
+
+ if(isotropic) {
cos_theta = (1.0f - 2.0f * randu);
- *pdf = M_1_PI_F * 0.25f;
+ if(pdf) {
+ *pdf = M_1_PI_F * 0.25f;
+ }
}
else {
float k = (1.0f - g * g) / (1.0f - g + 2.0f * g * randu);
cos_theta = (1.0f + g * g - k * k) / (2.0f * g);
- *pdf = single_peaked_henyey_greenstein(cos_theta, g);
+ if(pdf) {
+ *pdf = single_peaked_henyey_greenstein(cos_theta, g);
+ }
}
float sin_theta = safe_sqrtf(1.0f - cos_theta * cos_theta);
-
float phi = M_2PI_F * randv;
- cos_phi = cosf(phi);
- sin_phi = sinf(phi);
+ float3 dir = make_float3(sin_theta * cosf(phi), sin_theta * sinf(phi), cos_theta);
- /* note that I points towards the viewer and so is used negated */
float3 T, B;
- make_orthonormals(-I, &T, &B);
- *omega_in = sin_theta * cos_phi * T + sin_theta * sin_phi * B + cos_theta * (-I);
+ make_orthonormals(D, &T, &B);
+ dir = dir.x * T + dir.y * B + dir.z * D;
+
+ return dir;
+}
+
+ccl_device int volume_henyey_greenstein_sample(const ShaderClosure *sc, float3 I, float3 dIdx, float3 dIdy, float randu, float randv,
+ float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
+{
+ const HenyeyGreensteinVolume *volume = (const HenyeyGreensteinVolume*)sc;
+ float g = volume->g;
+ /* note that I points towards the viewer and so is used negated */
+ *omega_in = henyey_greenstrein_sample(-I, g, randu, randv, pdf);
*eval = make_float3(*pdf, *pdf, *pdf); /* perfect importance sampling */
#ifdef __RAY_DIFFERENTIALS__
diff --git a/intern/cycles/kernel/geom/geom_motion_triangle_intersect.h b/intern/cycles/kernel/geom/geom_motion_triangle_intersect.h
index 4a19f2ba031..542843edc84 100644
--- a/intern/cycles/kernel/geom/geom_motion_triangle_intersect.h
+++ b/intern/cycles/kernel/geom/geom_motion_triangle_intersect.h
@@ -248,23 +248,30 @@ ccl_device_inline void motion_triangle_intersect_local(
motion_triangle_vertices(kg, local_object, prim, time, verts);
/* Ray-triangle intersection, unoptimized. */
float t, u, v;
- if(ray_triangle_intersect(P,
- dir,
- tmax,
+ if(!ray_triangle_intersect(P,
+ dir,
+ tmax,
#if defined(__KERNEL_SSE2__) && defined(__KERNEL_SSE__)
- (ssef*)verts,
+ (ssef*)verts,
#else
- verts[0], verts[1], verts[2],
+ verts[0], verts[1], verts[2],
#endif
- &u, &v, &t))
+ &u, &v, &t))
{
+ return;
+ }
+
+ int hit;
+ if(lcg_state) {
+ /* Record up to max_hits intersections. */
for(int i = min(max_hits, local_isect->num_hits) - 1; i >= 0; --i) {
if(local_isect->hits[i].t == t) {
return;
}
}
+
local_isect->num_hits++;
- int hit;
+
if(local_isect->num_hits <= max_hits) {
hit = local_isect->num_hits - 1;
}
@@ -277,18 +284,29 @@ ccl_device_inline void motion_triangle_intersect_local(
if(hit >= max_hits)
return;
}
- /* Record intersection. */
- Intersection *isect = &local_isect->hits[hit];
- isect->t = t;
- isect->u = u;
- isect->v = v;
- isect->prim = prim_addr;
- isect->object = object;
- isect->type = PRIMITIVE_MOTION_TRIANGLE;
- /* Record geometric normal. */
- local_isect->Ng[hit] = normalize(cross(verts[1] - verts[0],
- verts[2] - verts[0]));
}
+ else {
+ /* Record closest intersection only. */
+ if(local_isect->num_hits && t > local_isect->hits[0].t) {
+ return;
+ }
+
+ hit = 0;
+ local_isect->num_hits = 1;
+ }
+
+ /* Record intersection. */
+ Intersection *isect = &local_isect->hits[hit];
+ isect->t = t;
+ isect->u = u;
+ isect->v = v;
+ isect->prim = prim_addr;
+ isect->object = object;
+ isect->type = PRIMITIVE_MOTION_TRIANGLE;
+
+ /* Record geometric normal. */
+ local_isect->Ng[hit] = normalize(cross(verts[1] - verts[0],
+ verts[2] - verts[0]));
}
#endif /* __BVH_LOCAL__ */
diff --git a/intern/cycles/kernel/geom/geom_triangle_intersect.h b/intern/cycles/kernel/geom/geom_triangle_intersect.h
index 7daa378f81e..a3b23115ae4 100644
--- a/intern/cycles/kernel/geom/geom_triangle_intersect.h
+++ b/intern/cycles/kernel/geom/geom_triangle_intersect.h
@@ -118,28 +118,40 @@ ccl_device_inline void triangle_intersect_local(
return;
}
- for(int i = min(max_hits, local_isect->num_hits) - 1; i >= 0; --i) {
- if(local_isect->hits[i].t == t) {
- return;
+ int hit;
+ if(lcg_state) {
+ /* Record up to max_hits intersections. */
+ for(int i = min(max_hits, local_isect->num_hits) - 1; i >= 0; --i) {
+ if(local_isect->hits[i].t == t) {
+ return;
+ }
}
- }
- local_isect->num_hits++;
- int hit;
+ local_isect->num_hits++;
+
+ if(local_isect->num_hits <= max_hits) {
+ hit = local_isect->num_hits - 1;
+ }
+ else {
+ /* reservoir sampling: if we are at the maximum number of
+ * hits, randomly replace element or skip it */
+ hit = lcg_step_uint(lcg_state) % local_isect->num_hits;
- if(local_isect->num_hits <= max_hits) {
- hit = local_isect->num_hits - 1;
+ if(hit >= max_hits)
+ return;
+ }
}
else {
- /* reservoir sampling: if we are at the maximum number of
- * hits, randomly replace element or skip it */
- hit = lcg_step_uint(lcg_state) % local_isect->num_hits;
-
- if(hit >= max_hits)
+ /* Record closest intersection only. */
+ if(local_isect->num_hits && t > local_isect->hits[0].t) {
return;
+ }
+
+ hit = 0;
+ local_isect->num_hits = 1;
}
- /* record intersection */
+ /* Record intersection. */
Intersection *isect = &local_isect->hits[hit];
isect->prim = prim_addr;
isect->object = object;
diff --git a/intern/cycles/kernel/kernel_path.h b/intern/cycles/kernel/kernel_path.h
index afca4575331..dbbb80ca37f 100644
--- a/intern/cycles/kernel/kernel_path.h
+++ b/intern/cycles/kernel/kernel_path.h
@@ -32,12 +32,12 @@
#include "kernel/kernel_light.h"
#include "kernel/kernel_passes.h"
-#ifdef __SUBSURFACE__
-# include "kernel/kernel_subsurface.h"
+#if defined(__VOLUME__) || defined(__SUBSURFACE__)
+# include "kernel/kernel_volume.h"
#endif
-#ifdef __VOLUME__
-# include "kernel/kernel_volume.h"
+#ifdef __SUBSURFACE__
+# include "kernel/kernel_subsurface.h"
#endif
#include "kernel/kernel_path_state.h"
diff --git a/intern/cycles/kernel/kernel_path_branched.h b/intern/cycles/kernel/kernel_path_branched.h
index 5f917d509ec..6fb55bda08d 100644
--- a/intern/cycles/kernel/kernel_path_branched.h
+++ b/intern/cycles/kernel/kernel_path_branched.h
@@ -350,6 +350,7 @@ ccl_device void kernel_branched_path_subsurface_scatter(KernelGlobals *kg,
int num_hits = subsurface_scatter_multi_intersect(kg,
&ss_isect,
sd,
+ &hit_state,
sc,
&lcg_state,
bssrdf_u, bssrdf_v,
diff --git a/intern/cycles/kernel/kernel_path_subsurface.h b/intern/cycles/kernel/kernel_path_subsurface.h
index a48bde6443e..71aea9e3b27 100644
--- a/intern/cycles/kernel/kernel_path_subsurface.h
+++ b/intern/cycles/kernel/kernel_path_subsurface.h
@@ -51,6 +51,7 @@ bool kernel_path_subsurface_scatter(
int num_hits = subsurface_scatter_multi_intersect(kg,
&ss_isect,
sd,
+
@@ Diff output truncated at 10240 characters. @@
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