blender
/
blender
136
405
Fork 586
Code Issues 6.2k Pull Requests 757 Projects 19 Wiki Activity

Fix T96417: Cycles issue with multiscatter GGX and self intersection avoidance 

When the light direction is not pointing away from the geometric normal and
there is a shadow terminator offset, self intersection is supposed to occur.
This commit is contained in:
Brecht Van Lommel 2022-03-15 15:59:07 +01:00 committed by Philipp Oeser
parent 233004789e
commit eb605ba788
Notes: blender-bot 2023-02-14 08:10:06 +01:00 
Referenced by issue #96417, Multiscatter GGX regression with non-zero roughness and a bump texture on a non-manifold object
Referenced by issue #96241, 3.1: Potential candidates for corrective releases
2 changed files with 30 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
intern/cycles/kernel/integrator/shade_surface.h
View File

@ -365,13 +365,15 @@ ccl_device_forceinline void integrate_surface_ao(KernelGlobals kg,
float ao_pdf;
sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
bool skip_self = true;
Ray ray ccl_optional_struct_init;
ray.P = shadow_ray_offset(kg, sd, ao_D);
ray.P = shadow_ray_offset(kg, sd, ao_D, &skip_self);
ray.D = ao_D;
ray.t = kernel_data.integrator.ao_bounces_distance;
ray.time = sd->time;
ray.self.object = sd->object;
ray.self.prim = sd->prim;
ray.self.object = (skip_self) ? sd->object : OBJECT_NONE;
ray.self.prim = (skip_self) ? sd->prim : PRIM_NONE;
ray.self.light_object = OBJECT_NONE;
ray.self.light_prim = PRIM_NONE;
ray.dP = differential_zero_compact();

44
intern/cycles/kernel/light/sample.h
View File

@ -193,11 +193,9 @@ ccl_device_inline float3 shadow_ray_smooth_surface_offset(
ccl_device_inline float3 shadow_ray_offset(KernelGlobals kg,
ccl_private const ShaderData *ccl_restrict sd,
float3 L)
float3 L,
bool *r_skip_self)
{
float NL = dot(sd->N, L);
bool transmit = (NL < 0.0f);
float3 Ng = (transmit ? -sd->Ng : sd->Ng);
float3 P = sd->P;
if ((sd->type & PRIMITIVE_TRIANGLE) && (sd->shader & SHADER_SMOOTH_NORMAL)) {
@ -207,19 +205,25 @@ ccl_device_inline float3 shadow_ray_offset(KernelGlobals kg,
* offset_cutoff = 0.1f means that 10-20% of rays will be affected. Also
* make a smooth transition near the threshold. */
if (offset_cutoff > 0.0f) {
float NgL = dot(Ng, L);
float offset_amount = 0.0f;
float NL = dot(sd->N, L);
const bool transmit = (NL < 0.0f);
if (NL < 0) {
NL = -NL;
}
if (NL < offset_cutoff) {
offset_amount = clamp(2.0f - (NgL + NL) / offset_cutoff, 0.0f, 1.0f);
}
else {
offset_amount = clamp(1.0f - NgL / offset_cutoff, 0.0f, 1.0f);
}
const float3 Ng = (transmit ? -sd->Ng : sd->Ng);
const float NgL = dot(Ng, L);
const float offset_amount = (NL < offset_cutoff) ?
clamp(2.0f - (NgL + NL) / offset_cutoff, 0.0f, 1.0f) :
clamp(1.0f - NgL / offset_cutoff, 0.0f, 1.0f);
if (offset_amount > 0.0f) {
P += shadow_ray_smooth_surface_offset(kg, sd, Ng) * offset_amount;
/* Only skip self intersections if light direction and geometric normal point in the same
* direction, otherwise we're meant to hit this surface. */
*r_skip_self = (NgL > 0.0f);
}
}
}
@ -230,7 +234,8 @@ ccl_device_inline float3 shadow_ray_offset(KernelGlobals kg,
ccl_device_inline void shadow_ray_setup(ccl_private const ShaderData *ccl_restrict sd,
ccl_private const LightSample *ccl_restrict ls,
const float3 P,
ccl_private Ray *ray)
ccl_private Ray *ray,
const bool skip_self)
{
if (ls->shader & SHADER_CAST_SHADOW) {
/* setup ray */
@ -259,10 +264,10 @@ ccl_device_inline void shadow_ray_setup(ccl_private const ShaderData *ccl_restri
ray->time = sd->time;
/* Fill in intersection surface and light details. */
ray->self.prim = sd->prim;
ray->self.object = sd->object;
ray->self.light_prim = ls->prim;
ray->self.object = (skip_self) ? sd->object : OBJECT_NONE;
ray->self.prim = (skip_self) ? sd->prim : PRIM_NONE;
ray->self.light_object = ls->object;
ray->self.light_prim = ls->prim;
}
/* Create shadow ray towards light sample. */
@ -272,8 +277,9 @@ ccl_device_inline void light_sample_to_surface_shadow_ray(
ccl_private const LightSample *ccl_restrict ls,
ccl_private Ray *ray)
{
const float3 P = shadow_ray_offset(kg, sd, ls->D);
shadow_ray_setup(sd, ls, P, ray);
bool skip_self = true;
const float3 P = shadow_ray_offset(kg, sd, ls->D, &skip_self);
shadow_ray_setup(sd, ls, P, ray, skip_self);
}
/* Create shadow ray towards light sample. */
@ -284,7 +290,7 @@ ccl_device_inline void light_sample_to_volume_shadow_ray(
const float3 P,
ccl_private Ray *ray)
{
shadow_ray_setup(sd, ls, P, ray);
shadow_ray_setup(sd, ls, P, ray, false);
}
ccl_device_inline float light_sample_mis_weight_forward(KernelGlobals kg,