diff options
Diffstat (limited to 'intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h')
| -rw-r--r-- | intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h | 353 |
1 files changed, 188 insertions, 165 deletions
diff --git a/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h b/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h index 4e7425bd800..b3b1c37748d 100644 --- a/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h +++ b/intern/cycles/kernel/closure/bsdf_ashikhmin_shirley.h @@ -33,203 +33,226 @@ CCL_NAMESPACE_BEGIN ccl_device int bsdf_ashikhmin_shirley_setup(MicrofacetBsdf *bsdf) { - bsdf->alpha_x = clamp(bsdf->alpha_x, 1e-4f, 1.0f); - bsdf->alpha_y = bsdf->alpha_x; + bsdf->alpha_x = clamp(bsdf->alpha_x, 1e-4f, 1.0f); + bsdf->alpha_y = bsdf->alpha_x; - bsdf->type = CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID; - return SD_BSDF|SD_BSDF_HAS_EVAL; + bsdf->type = CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID; + return SD_BSDF | SD_BSDF_HAS_EVAL; } ccl_device int bsdf_ashikhmin_shirley_aniso_setup(MicrofacetBsdf *bsdf) { - bsdf->alpha_x = clamp(bsdf->alpha_x, 1e-4f, 1.0f); - bsdf->alpha_y = clamp(bsdf->alpha_y, 1e-4f, 1.0f); + bsdf->alpha_x = clamp(bsdf->alpha_x, 1e-4f, 1.0f); + bsdf->alpha_y = clamp(bsdf->alpha_y, 1e-4f, 1.0f); - bsdf->type = CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ANISO_ID; - return SD_BSDF|SD_BSDF_HAS_EVAL; + bsdf->type = CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ANISO_ID; + return SD_BSDF | SD_BSDF_HAS_EVAL; } ccl_device void bsdf_ashikhmin_shirley_blur(ShaderClosure *sc, float roughness) { - MicrofacetBsdf *bsdf = (MicrofacetBsdf*)sc; + MicrofacetBsdf *bsdf = (MicrofacetBsdf *)sc; - bsdf->alpha_x = fmaxf(roughness, bsdf->alpha_x); - bsdf->alpha_y = fmaxf(roughness, bsdf->alpha_y); + bsdf->alpha_x = fmaxf(roughness, bsdf->alpha_x); + bsdf->alpha_y = fmaxf(roughness, bsdf->alpha_y); } ccl_device_inline float bsdf_ashikhmin_shirley_roughness_to_exponent(float roughness) { - return 2.0f / (roughness*roughness) - 2.0f; + return 2.0f / (roughness * roughness) - 2.0f; } -ccl_device_forceinline float3 bsdf_ashikhmin_shirley_eval_reflect( - const ShaderClosure *sc, - const float3 I, - const float3 omega_in, - float *pdf) +ccl_device_forceinline float3 bsdf_ashikhmin_shirley_eval_reflect(const ShaderClosure *sc, + const float3 I, + const float3 omega_in, + float *pdf) { - const MicrofacetBsdf *bsdf = (const MicrofacetBsdf*)sc; - float3 N = bsdf->N; - - float NdotI = dot(N, I); /* in Cycles/OSL convention I is omega_out */ - float NdotO = dot(N, omega_in); /* and consequently we use for O omaga_in ;) */ - - float out = 0.0f; - - if(fmaxf(bsdf->alpha_x, bsdf->alpha_y) <= 1e-4f) - return make_float3(0.0f, 0.0f, 0.0f); - - if(NdotI > 0.0f && NdotO > 0.0f) { - NdotI = fmaxf(NdotI, 1e-6f); - NdotO = fmaxf(NdotO, 1e-6f); - float3 H = normalize(omega_in + I); - float HdotI = fmaxf(fabsf(dot(H, I)), 1e-6f); - float HdotN = fmaxf(dot(H, N), 1e-6f); - - float pump = 1.0f / fmaxf(1e-6f, (HdotI*fmaxf(NdotO, NdotI))); /* pump from original paper (first derivative disc., but cancels the HdotI in the pdf nicely) */ - /*float pump = 1.0f / fmaxf(1e-4f, ((NdotO + NdotI) * (NdotO*NdotI))); */ /* pump from d-brdf paper */ - - float n_x = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_x); - float n_y = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_y); - - if(n_x == n_y) { - /* isotropic */ - float e = n_x; - float lobe = powf(HdotN, e); - float norm = (n_x + 1.0f) / (8.0f * M_PI_F); - - out = NdotO * norm * lobe * pump; - *pdf = norm * lobe / HdotI; /* this is p_h / 4(H.I) (conversion from 'wh measure' to 'wi measure', eq. 8 in paper) */ - } - else { - /* anisotropic */ - float3 X, Y; - make_orthonormals_tangent(N, bsdf->T, &X, &Y); - - float HdotX = dot(H, X); - float HdotY = dot(H, Y); - float lobe; - if(HdotN < 1.0f) { - float e = (n_x * HdotX*HdotX + n_y * HdotY*HdotY) / (1.0f - HdotN*HdotN); - lobe = powf(HdotN, e); - } - else { - lobe = 1.0f; - } - float norm = sqrtf((n_x + 1.0f)*(n_y + 1.0f)) / (8.0f * M_PI_F); - - out = NdotO * norm * lobe * pump; - *pdf = norm * lobe / HdotI; - } - } - - return make_float3(out, out, out); + const MicrofacetBsdf *bsdf = (const MicrofacetBsdf *)sc; + float3 N = bsdf->N; + + float NdotI = dot(N, I); /* in Cycles/OSL convention I is omega_out */ + float NdotO = dot(N, omega_in); /* and consequently we use for O omaga_in ;) */ + + float out = 0.0f; + + if (fmaxf(bsdf->alpha_x, bsdf->alpha_y) <= 1e-4f) + return make_float3(0.0f, 0.0f, 0.0f); + + if (NdotI > 0.0f && NdotO > 0.0f) { + NdotI = fmaxf(NdotI, 1e-6f); + NdotO = fmaxf(NdotO, 1e-6f); + float3 H = normalize(omega_in + I); + float HdotI = fmaxf(fabsf(dot(H, I)), 1e-6f); + float HdotN = fmaxf(dot(H, N), 1e-6f); + + float pump = + 1.0f / + fmaxf( + 1e-6f, + (HdotI * + fmaxf( + NdotO, + NdotI))); /* pump from original paper (first derivative disc., but cancels the HdotI in the pdf nicely) */ + /*float pump = 1.0f / fmaxf(1e-4f, ((NdotO + NdotI) * (NdotO*NdotI))); */ /* pump from d-brdf paper */ + + float n_x = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_x); + float n_y = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_y); + + if (n_x == n_y) { + /* isotropic */ + float e = n_x; + float lobe = powf(HdotN, e); + float norm = (n_x + 1.0f) / (8.0f * M_PI_F); + + out = NdotO * norm * lobe * pump; + *pdf = + norm * lobe / + HdotI; /* this is p_h / 4(H.I) (conversion from 'wh measure' to 'wi measure', eq. 8 in paper) */ + } + else { + /* anisotropic */ + float3 X, Y; + make_orthonormals_tangent(N, bsdf->T, &X, &Y); + + float HdotX = dot(H, X); + float HdotY = dot(H, Y); + float lobe; + if (HdotN < 1.0f) { + float e = (n_x * HdotX * HdotX + n_y * HdotY * HdotY) / (1.0f - HdotN * HdotN); + lobe = powf(HdotN, e); + } + else { + lobe = 1.0f; + } + float norm = sqrtf((n_x + 1.0f) * (n_y + 1.0f)) / (8.0f * M_PI_F); + + out = NdotO * norm * lobe * pump; + *pdf = norm * lobe / HdotI; + } + } + + return make_float3(out, out, out); } -ccl_device float3 bsdf_ashikhmin_shirley_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf) +ccl_device float3 bsdf_ashikhmin_shirley_eval_transmit(const ShaderClosure *sc, + const float3 I, + const float3 omega_in, + float *pdf) { - return make_float3(0.0f, 0.0f, 0.0f); + return make_float3(0.0f, 0.0f, 0.0f); } -ccl_device_inline void bsdf_ashikhmin_shirley_sample_first_quadrant(float n_x, float n_y, float randu, float randv, float *phi, float *cos_theta) +ccl_device_inline void bsdf_ashikhmin_shirley_sample_first_quadrant( + float n_x, float n_y, float randu, float randv, float *phi, float *cos_theta) { - *phi = atanf(sqrtf((n_x + 1.0f) / (n_y + 1.0f)) * tanf(M_PI_2_F * randu)); - float cos_phi = cosf(*phi); - float sin_phi = sinf(*phi); - *cos_theta = powf(randv, 1.0f / (n_x * cos_phi*cos_phi + n_y * sin_phi*sin_phi + 1.0f)); + *phi = atanf(sqrtf((n_x + 1.0f) / (n_y + 1.0f)) * tanf(M_PI_2_F * randu)); + float cos_phi = cosf(*phi); + float sin_phi = sinf(*phi); + *cos_theta = powf(randv, 1.0f / (n_x * cos_phi * cos_phi + n_y * sin_phi * sin_phi + 1.0f)); } -ccl_device int bsdf_ashikhmin_shirley_sample(const ShaderClosure *sc, 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_ashikhmin_shirley_sample(const ShaderClosure *sc, + 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) { - const MicrofacetBsdf *bsdf = (const MicrofacetBsdf*)sc; - float3 N = bsdf->N; - int label = LABEL_REFLECT | LABEL_GLOSSY; - - float NdotI = dot(N, I); - if(NdotI > 0.0f) { - - float n_x = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_x); - float n_y = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_y); - - /* get x,y basis on the surface for anisotropy */ - float3 X, Y; - - if(n_x == n_y) - make_orthonormals(N, &X, &Y); - else - make_orthonormals_tangent(N, bsdf->T, &X, &Y); - - /* sample spherical coords for h in tangent space */ - float phi; - float cos_theta; - if(n_x == n_y) { - /* isotropic sampling */ - phi = M_2PI_F * randu; - cos_theta = powf(randv, 1.0f / (n_x + 1.0f)); - } - else { - /* anisotropic sampling */ - if(randu < 0.25f) { /* first quadrant */ - float remapped_randu = 4.0f * randu; - bsdf_ashikhmin_shirley_sample_first_quadrant(n_x, n_y, remapped_randu, randv, &phi, &cos_theta); - } - else if(randu < 0.5f) { /* second quadrant */ - float remapped_randu = 4.0f * (.5f - randu); - bsdf_ashikhmin_shirley_sample_first_quadrant(n_x, n_y, remapped_randu, randv, &phi, &cos_theta); - phi = M_PI_F - phi; - } - else if(randu < 0.75f) { /* third quadrant */ - float remapped_randu = 4.0f * (randu - 0.5f); - bsdf_ashikhmin_shirley_sample_first_quadrant(n_x, n_y, remapped_randu, randv, &phi, &cos_theta); - phi = M_PI_F + phi; - } - else { /* fourth quadrant */ - float remapped_randu = 4.0f * (1.0f - randu); - bsdf_ashikhmin_shirley_sample_first_quadrant(n_x, n_y, remapped_randu, randv, &phi, &cos_theta); - phi = 2.0f * M_PI_F - phi; - } - } - - /* get half vector in tangent space */ - float sin_theta = sqrtf(fmaxf(0.0f, 1.0f - cos_theta*cos_theta)); - float cos_phi = cosf(phi); - float sin_phi = sinf(phi); /* no sqrt(1-cos^2) here b/c it causes artifacts */ - float3 h = make_float3( - sin_theta * cos_phi, - sin_theta * sin_phi, - cos_theta - ); - - /* half vector to world space */ - float3 H = h.x*X + h.y*Y + h.z*N; - float HdotI = dot(H, I); - if(HdotI < 0.0f) H = -H; - - /* reflect I on H to get omega_in */ - *omega_in = -I + (2.0f * HdotI) * H; - - if(fmaxf(bsdf->alpha_x, bsdf->alpha_y) <= 1e-4f) { - /* Some high number for MIS. */ - *pdf = 1e6f; - *eval = make_float3(1e6f, 1e6f, 1e6f); - label = LABEL_REFLECT | LABEL_SINGULAR; - } - else { - /* leave the rest to eval_reflect */ - *eval = bsdf_ashikhmin_shirley_eval_reflect(sc, I, *omega_in, pdf); - } + const MicrofacetBsdf *bsdf = (const MicrofacetBsdf *)sc; + float3 N = bsdf->N; + int label = LABEL_REFLECT | LABEL_GLOSSY; + + float NdotI = dot(N, I); + if (NdotI > 0.0f) { + + float n_x = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_x); + float n_y = bsdf_ashikhmin_shirley_roughness_to_exponent(bsdf->alpha_y); + + /* get x,y basis on the surface for anisotropy */ + float3 X, Y; + + if (n_x == n_y) + make_orthonormals(N, &X, &Y); + else + make_orthonormals_tangent(N, bsdf->T, &X, &Y); + + /* sample spherical coords for h in tangent space */ + float phi; + float cos_theta; + if (n_x == n_y) { + /* isotropic sampling */ + phi = M_2PI_F * randu; + cos_theta = powf(randv, 1.0f / (n_x + 1.0f)); + } + else { + /* anisotropic sampling */ + if (randu < 0.25f) { /* first quadrant */ + float remapped_randu = 4.0f * randu; + bsdf_ashikhmin_shirley_sample_first_quadrant( + n_x, n_y, remapped_randu, randv, &phi, &cos_theta); + } + else if (randu < 0.5f) { /* second quadrant */ + float remapped_randu = 4.0f * (.5f - randu); + bsdf_ashikhmin_shirley_sample_first_quadrant( + n_x, n_y, remapped_randu, randv, &phi, &cos_theta); + phi = M_PI_F - phi; + } + else if (randu < 0.75f) { /* third quadrant */ + float remapped_randu = 4.0f * (randu - 0.5f); + bsdf_ashikhmin_shirley_sample_first_quadrant( + n_x, n_y, remapped_randu, randv, &phi, &cos_theta); + phi = M_PI_F + phi; + } + else { /* fourth quadrant */ + float remapped_randu = 4.0f * (1.0f - randu); + bsdf_ashikhmin_shirley_sample_first_quadrant( + n_x, n_y, remapped_randu, randv, &phi, &cos_theta); + phi = 2.0f * M_PI_F - phi; + } + } + + /* get half vector in tangent space */ + float sin_theta = sqrtf(fmaxf(0.0f, 1.0f - cos_theta * cos_theta)); + float cos_phi = cosf(phi); + float sin_phi = sinf(phi); /* no sqrt(1-cos^2) here b/c it causes artifacts */ + float3 h = make_float3(sin_theta * cos_phi, sin_theta * sin_phi, cos_theta); + + /* half vector to world space */ + float3 H = h.x * X + h.y * Y + h.z * N; + float HdotI = dot(H, I); + if (HdotI < 0.0f) + H = -H; + + /* reflect I on H to get omega_in */ + *omega_in = -I + (2.0f * HdotI) * H; + + if (fmaxf(bsdf->alpha_x, bsdf->alpha_y) <= 1e-4f) { + /* Some high number for MIS. */ + *pdf = 1e6f; + *eval = make_float3(1e6f, 1e6f, 1e6f); + label = LABEL_REFLECT | LABEL_SINGULAR; + } + else { + /* leave the rest to eval_reflect */ + *eval = bsdf_ashikhmin_shirley_eval_reflect(sc, I, *omega_in, pdf); + } #ifdef __RAY_DIFFERENTIALS__ - /* just do the reflection thing for now */ - *domega_in_dx = (2.0f * dot(N, dIdx)) * N - dIdx; - *domega_in_dy = (2.0f * dot(N, dIdy)) * N - dIdy; + /* just do the reflection thing for now */ + *domega_in_dx = (2.0f * dot(N, dIdx)) * N - dIdx; + *domega_in_dy = (2.0f * dot(N, dIdy)) * N - dIdy; #endif - } + } - return label; + return label; } - CCL_NAMESPACE_END -#endif /* __BSDF_ASHIKHMIN_SHIRLEY_H__ */ +#endif /* __BSDF_ASHIKHMIN_SHIRLEY_H__ */ |