[Bf-blender-cvs] [9b26206] cycles_disney_brdf: disney diffuse is working correctly
Pascal Schoen
noreply at git.blender.org
Tue May 17 10:46:46 CEST 2016
Commit: 9b262063767d6b05a617891c967d887d21bfb177
Author: Pascal Schoen
Date: Mon Apr 18 15:21:32 2016 +0200
Branches: cycles_disney_brdf
https://developer.blender.org/rB9b262063767d6b05a617891c967d887d21bfb177
disney diffuse is working correctly
===================================================================
M intern/cycles/kernel/closure/bsdf_disney_diffuse.h
M intern/cycles/kernel/osl/bsdf_disney_diffuse.cpp
M intern/cycles/kernel/shaders/stdosl.h
===================================================================
diff --git a/intern/cycles/kernel/closure/bsdf_disney_diffuse.h b/intern/cycles/kernel/closure/bsdf_disney_diffuse.h
index 2b927c5..ff69a7a 100644
--- a/intern/cycles/kernel/closure/bsdf_disney_diffuse.h
+++ b/intern/cycles/kernel/closure/bsdf_disney_diffuse.h
@@ -1,3 +1,4 @@
+
/*
* Adapted from Open Shading Language with this license:
*
@@ -30,12 +31,153 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-#ifndef __BSDF_DISNEY_DIFFUSE_
+#ifndef __BSDF_DISNEY_DIFFUSE_H__
#define __BSDF_DISNEY_DIFFUSE_H__
+#include <cmath>
+
CCL_NAMESPACE_BEGIN
-/* DIFFUSE */
+/* DISNEY DIFFUSE */
+
+ccl_device float diff_sqr(float a) {
+ return a * a;
+}
+
+ccl_device float3 diff_mon2lin(float3 x, float gamma) {
+ return make_float3(pow(x[0], gamma), pow(x[1], gamma), pow(x[2], gamma));
+}
+
+ccl_device float diff_GTR1(float NdotH, float a) {
+ if (a >= 1.0f) return 1.0f / M_PI_F;
+ float a2 = a*a;
+ float t = 1.0f + (a2 - 1.0f) * NdotH * NdotH;
+ return (a2 - 1.0f) / (M_PI_F * log(a2) * t);
+}
+
+ccl_device float diff_GTR2(float NdotH, float a) {
+ float a2 = a * a;
+ float t = 1.0f + (a2 - 1.0f) * NdotH * NdotH;
+ return a2 / (M_PI_F * t * t);
+}
+
+ccl_device float diff_GTR2_aniso(
+ float NdotH,
+ float HdotX,
+ float HdotY,
+ float ax,
+ float ay)
+{
+ return 1.0f / (M_PI_F * ax * ay * diff_sqr(diff_sqr(HdotX / ax) + diff_sqr(HdotY / ay)
+ + NdotH * NdotH));
+}
+
+ccl_device float diff_smithG_GGX(float Ndotv, float alphaG) {
+ float a = alphaG * alphaG;
+ float b = Ndotv * Ndotv;
+ return 1.0f / (Ndotv + sqrtf(a + b - a * b));
+}
+
+ccl_device float diff_SchlickFresnel(float u) {
+ float m = clamp(1.0f - u, 0.0f, 1.0f);
+ float m2 = m * m;
+ return m2 * m2 * m; // pow(m, 5)
+}
+
+ccl_device float3 diff_transform_to_local(const float3& v, const float3& n,
+ const float3& x, const float3& y)
+{
+ return make_float3(dot(v, x), dot(v, n), dot(v, y));
+}
+
+ccl_device float3 diff_mix(float3 x, float3 y, float a) {
+ return x * (1.0f - a) + y * a;
+}
+
+ccl_device float diff_mix(float x, float y, float a) {
+ return x * (1.0f - a) + y * a;
+}
+
+/* structures */
+struct DisneyDiffuseBRDFParams {
+ // brdf parameters
+ float3 m_base_color;
+ float m_subsurface;
+ float m_roughness;
+ float m_sheen;
+ float m_sheen_tint;
+
+ // color correction
+ float m_withNdotL;
+ float m_brightness;
+ float m_gamma;
+ float m_exposure;
+ float m_mon2lingamma;
+
+ // precomputed values
+ float3 m_cdlin, m_ctint, m_csheen;
+ float m_cdlum;
+ float m_weights[4];
+ bool m_withNdotL_b;
+
+ void precompute_values() {
+ m_cdlin = diff_mon2lin(m_base_color, m_mon2lingamma); //make_float3(1.0f, 0.795f, 0.0f));
+ m_cdlum = 0.3f * m_cdlin[0] + 0.6f * m_cdlin[1] + 0.1f * m_cdlin[2]; // luminance approx.
+
+ m_ctint = m_cdlum > 0.0f ? m_cdlin / m_cdlum : make_float3(1.0f, 1.0f, 1.0f); // normalize lum. to isolate hue+sat
+ m_csheen = diff_mix(make_float3(1.0f, 1.0f, 1.0f), m_ctint, m_sheen_tint);
+
+ m_gamma = clamp(m_gamma, 0.0f, 5.0f);
+ m_exposure = clamp(m_exposure, -6.0f, 6.0f);
+ m_withNdotL_b = (m_withNdotL > 0.5f);
+ }
+};
+
+typedef struct DisneyDiffuseBRDFParams DisneyDiffuseBRDFParams;
+
+/* brdf */
+ccl_device float3 calculate_disney_diffuse_brdf(const ShaderClosure *sc,
+ const DisneyDiffuseBRDFParams *params, float3 N, float3 V, float3 L,
+ float3 H, float *pdf)
+{
+ float NdotL = dot(N, L);
+ float NdotV = dot(N, V);
+
+ if (NdotL < 0 || NdotV < 0) {
+ *pdf = 0.0f;
+ return make_float3(0.0f, 0.0f, 0.0f);
+ }
+
+ float LdotH = dot(L, H);
+
+ float Fd = 0.0f;
+ float FL = diff_SchlickFresnel(NdotL), FV = diff_SchlickFresnel(NdotV);
+
+ if (params->m_subsurface != 1.0f) {
+ const float Fd90 = 0.5f + 2.0f * LdotH*LdotH * params->m_roughness;
+ Fd = diff_mix(1.0f, Fd90, FL) * diff_mix(1.0f, Fd90, FV);
+ }
+
+ if (params->m_subsurface > 0.0f) {
+ float Fss90 = LdotH*LdotH * params->m_roughness;
+ float Fss = diff_mix(1.0f, Fss90, FL) * diff_mix(1.0f, Fss90, FV);
+ float ss = 1.25f * (Fss * (1.0f / (NdotL + NdotV) - 0.5f) + 0.5f);
+ Fd = diff_mix(Fd, ss, params->m_subsurface);
+ }
+
+ float3 value = M_1_PI_F * Fd * params->m_cdlin;
+ *pdf = NdotL * M_1_PI_F * params->m_cdlum;
+
+ // sheen component
+ if (params->m_sheen != 0.0f) {
+ float FH = diff_SchlickFresnel(LdotH);
+
+ value += FH * params->m_sheen * params->m_csheen;
+ *pdf += (1.0f / M_2PI_F) * params->m_sheen;
+ }
+
+ return value;
+}
ccl_device int bsdf_disney_diffuse_setup(ShaderClosure *sc)
{
@@ -44,46 +186,168 @@ ccl_device int bsdf_disney_diffuse_setup(ShaderClosure *sc)
}
ccl_device float3 bsdf_disney_diffuse_eval_reflect(const ShaderClosure *sc,
- float3 color, const float3 I, const float3 omega_in, float *pdf)
+ const DisneyDiffuseBRDFParams *params, const float3 I,
+ const float3 omega_in, float *pdf)
{
- float3 N = sc->N;
+ float3 N = normalize(sc->N);
+ float3 V = I; // outgoing
+ float3 L = omega_in; // incoming
+ float3 H = normalize(L + V);
+
+ if (dot(sc->N, omega_in) > 0.0f) {
+ float3 value = calculate_disney_diffuse_brdf(sc, params, N, V, L, H, pdf);
+
+ value *= dot(N, L);
+
+ // brightness
+ value *= params->m_brightness;
- float cos_pi = fmaxf(dot(N, omega_in), 0.0f) * M_1_PI_F;
- *pdf = cos_pi;
- return make_float3(cos_pi * color[0], cos_pi * color[1], cos_pi * color[2]);
+ // exposure
+ value *= pow(2.0f, params->m_exposure);
+
+ // gamma
+ value[0] = pow(value[0], 1.0f / params->m_gamma);
+ value[1] = pow(value[1], 1.0f / params->m_gamma);
+ value[2] = pow(value[2], 1.0f / params->m_gamma);
+
+ return value;
+ }
+ else {
+ *pdf = 0.0f;
+ return make_float3(0.0f, 0.0f, 0.0f);
+ }
}
-ccl_device float3 bsdf_disney_diffuse_eval_transmit(const ShaderClosure *sc,
- float3 color, const float3 I, const float3 omega_in, float *pdf)
+ccl_device float3 bsdf_disney_diffuse_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
{
return make_float3(0.0f, 0.0f, 0.0f);
}
-ccl_device int bsdf_disney_diffuse_sample(const ShaderClosure *sc, float3 color,
- float3 Ng, 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 int bsdf_disney_diffuse_sample(const ShaderClosure *sc, const DisneyDiffuseBRDFParams *params,
+ float3 Ng, 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)
{
- float3 N = sc->N;
+ float3 N = normalize(sc->N);
+
+ sample_uniform_hemisphere(N, randu, randv, omega_in, pdf);
+
+ if (dot(Ng, *omega_in) > 0) {
+ float3 V = I; // outgoing
+ float3 L = *omega_in; // incoming
+ float3 H = normalize(L + V);
+
+ float3 value = calculate_disney_diffuse_brdf(sc, params, N, V, L, H, pdf);
+
+ if (params->m_withNdotL_b)
+ value *= dot(N, L);
+
+ // brightness
+ value *= params->m_brightness;
+
+ // exposure
+ value *= pow(2.0f, params->m_exposure);
+
+ // gamma
+ value[0] = pow(value[0], 1.0f / params->m_gamma);
+ value[1] = pow(value[1], 1.0f / params->m_gamma);
+ value[2] = pow(value[2], 1.0f / params->m_gamma);
+
+ *eval = make_float3(value[0], value[1], value[2]);
+
+#ifdef __RAY_DIFFERENTIALS__
+ // TODO: find a better approximation for the diffuse bounce
+ *domega_in_dx = -((2 * dot(N, dIdx)) * N - dIdx);
+ *domega_in_dy = -((2 * dot(N, dIdy)) * N - dIdy);
+#endif
+ }
+ else {
+ *pdf = 0;
+ }
+ /*// we are viewing the surface from the right side - send a ray out with cosine
// distribution over the hemisphere
- sample_cos_hemisphere(N, randu, randv, omega_in, pdf);
+ sample_cos_hemisphere(-N, randu, randv, omega_in, pdf);
+ if(dot(Ng, *omega_in) < 0) {
+ float3 H = normalize(*omega_in - I);
+ *eval = calculate_disney_diffuse_brdf(sc, params, -N, -I, *omega_in, H, pdf);
+
+ // multiply with NdotL
+ //if (params->m_withNdotL_b)
+ // *eval *= dot(N, L);
+
+ // brightness
+ *eval *= params->m_brightness;
+
+ // exposure
+ *eval *= pow(2.0f, params->m_exposure);
+
+ // gamma
+ (*eval)[0] = pow((*eval)[0], 1.0f / params->m_gamma);
+ (*eval)[1] = pow((*eval)[1], 1.0f / params->m_gamma);
+ (*eval)[2] = pow((*eval)[2], 1.0f / params->m_gamma);
+ //*eval = make_float3(*pdf, *pdf, *pdf);
- if(dot(Ng, *omega_in) > 0.0f) {
- *eval = make_float3(*pdf * color[0], *pdf * color[1], *pdf * color[2]);
#ifdef __RAY_DIFFERENTIALS__
// TODO: find a better approximation for the diffuse bounce
- *domega_in_dx = (2 * dot(N, dIdx)) * N - dIdx;
- *domega_in_dy = (2 * dot(N, dIdy)) * N - dIdy;
+ *domega_in_dx = -((2 * dot(N, dIdx)) * N - dIdx);
+ *domega_in_dy = -((2 * dot(N, dIdy)) * N - dIdy);
#endif
}
- else
- *pdf = 0.0f;
+ else {
+ *pdf = 0;
+ }*/
+ return LABEL_DIFFUSE;
+
+ /*float3 N = normalize(sc->N);
+ float3 T = normalize(sc->T);
+ float3 X, Y;
+
+ float cos_theta, phi, theta, sin_phi, cos_phi;
+
+ make_orthonormals_tangent(N, T, &X, &Y);
+
+ phi = 2.0f * M_PI_F * randu;
+ theta = 2.0f * M_PI_F * randv;
+ cos_theta = cosf(theta);
+ sin_phi = sinf(phi);
+ cos_phi = cosf(phi);
+
+ float sin_theta = sqrtf(fmaxf(0.0f, 1.0f - cos_theta * cos_theta));
+ float3 H = normalize(sin_theta * cos_phi * X + sin_theta * sin_phi * Y + cos_theta * N);
+
+ *omega_in = 2.0f * dot(I, H) * H - I;
- return LABEL_REFLECT|LABEL_DIFFUSE;
+ float3 V = I; // outgoing
+ float3 L = *omega_in; // incoming
+
+ *eval = calculate_disney_diffuse_brdf(sc, params, N, V, L, H, pdf);
+
+ // multiply with NdotL
+ //if (params->m_withNdotL_b)
+ // *eval *= dot(N, L);
+
+ // brightness
+ *eval *= params->m_brightness;
+
+ // exposure
+ *eval *= pow(2.0f, params->m_exposure);
+
+ // gamma
+ (*eval)[0] = pow((*eval)[0], 1.0f / params->m_gamma);
+ (*eval)[1] = pow((*eval)[1], 1.0f / params->m_gamma);
+ (*eval)[2] = pow((*eval)[2], 1.0f / params->m_gamma);
+
+#ifdef __RAY_DIFFERENTIALS__
+ *domega_in_dx = 2 * dot(N, dIdx) * N - dIdx;
+ *domega_in_dy = 2 * dot(N, dIdy) * N - dIdy;
+#endif
+
+ return LABEL_REFLECT|LABEL_DIFFUSE;*/
}
C
@@ Diff output truncated at 10240 characters. @@
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