diff options
Diffstat (limited to 'intern/cycles/kernel/closure/bsdf_microfacet_multi.h')
| -rw-r--r-- | intern/cycles/kernel/closure/bsdf_microfacet_multi.h | 215 |
1 files changed, 144 insertions, 71 deletions
diff --git a/intern/cycles/kernel/closure/bsdf_microfacet_multi.h b/intern/cycles/kernel/closure/bsdf_microfacet_multi.h index 7d87727004f..2f2c35d5d1f 100644 --- a/intern/cycles/kernel/closure/bsdf_microfacet_multi.h +++ b/intern/cycles/kernel/closure/bsdf_microfacet_multi.h @@ -40,20 +40,20 @@ ccl_device_forceinline float D_ggx_aniso(const float3 wm, const float2 alpha) } /* Sample slope distribution (based on page 14 of the supplemental implementation). */ -ccl_device_forceinline float2 mf_sampleP22_11(const float cosI, const float2 randU) +ccl_device_forceinline float2 mf_sampleP22_11(const float cosI, const float randx, const float randy) { - if(cosI > 0.9999f || cosI < 1e-6f) { - const float r = sqrtf(randU.x / max(1.0f - randU.x, 1e-7f)); - const float phi = M_2PI_F * randU.y; + if(cosI > 0.9999f || fabsf(cosI) < 1e-6f) { + const float r = sqrtf(randx / max(1.0f - randx, 1e-7f)); + const float phi = M_2PI_F * randy; return make_float2(r*cosf(phi), r*sinf(phi)); } - const float sinI = sqrtf(1.0f - cosI*cosI); + const float sinI = safe_sqrtf(1.0f - cosI*cosI); const float tanI = sinI/cosI; const float projA = 0.5f * (cosI + 1.0f); if(projA < 0.0001f) return make_float2(0.0f, 0.0f); - const float A = 2.0f*randU.x*projA / cosI - 1.0f; + const float A = 2.0f*randx*projA / cosI - 1.0f; float tmp = A*A-1.0f; if(fabsf(tmp) < 1e-7f) return make_float2(0.0f, 0.0f); @@ -64,24 +64,24 @@ ccl_device_forceinline float2 mf_sampleP22_11(const float cosI, const float2 ran const float slopeX = (A < 0.0f || slopeX2 > 1.0f/tanI)? (tanI*tmp - D) : slopeX2; float U2; - if(randU.y >= 0.5f) - U2 = 2.0f*(randU.y - 0.5f); + if(randy >= 0.5f) + U2 = 2.0f*(randy - 0.5f); else - U2 = 2.0f*(0.5f - randU.y); + U2 = 2.0f*(0.5f - randy); const float z = (U2*(U2*(U2*0.27385f-0.73369f)+0.46341f)) / (U2*(U2*(U2*0.093073f+0.309420f)-1.0f)+0.597999f); const float slopeY = z * sqrtf(1.0f + slopeX*slopeX); - if(randU.y >= 0.5f) + if(randy >= 0.5f) return make_float2(slopeX, slopeY); else return make_float2(slopeX, -slopeY); } /* Visible normal sampling for the GGX distribution (based on page 7 of the supplemental implementation). */ -ccl_device_forceinline float3 mf_sample_vndf(const float3 wi, const float2 alpha, const float2 randU) +ccl_device_forceinline float3 mf_sample_vndf(const float3 wi, const float2 alpha, const float randx, const float randy) { const float3 wi_11 = normalize(make_float3(alpha.x*wi.x, alpha.y*wi.y, wi.z)); - const float2 slope_11 = mf_sampleP22_11(wi_11.z, randU); + const float2 slope_11 = mf_sampleP22_11(wi_11.z, randx, randy); const float3 cossin_phi = safe_normalize(make_float3(wi_11.x, wi_11.y, 0.0f)); const float slope_x = alpha.x*(cossin_phi.x * slope_11.x - cossin_phi.y * slope_11.y); @@ -91,18 +91,15 @@ ccl_device_forceinline float3 mf_sample_vndf(const float3 wi, const float2 alpha return normalize(make_float3(-slope_x, -slope_y, 1.0f)); } -/* === Phase functions: Glossy, Diffuse and Glass === */ +/* === Phase functions: Glossy and Glass === */ -/* Phase function for reflective materials, either without a fresnel term (for compatibility) or with the conductive fresnel term. */ -ccl_device_forceinline float3 mf_sample_phase_glossy(const float3 wi, float3 *n, float3 *k, float3 *weight, const float3 wm) +/* Phase function for reflective materials. */ +ccl_device_forceinline float3 mf_sample_phase_glossy(const float3 wi, float3 *weight, const float3 wm) { - if(n && k) - *weight *= fresnel_conductor(dot(wi, wm), *n, *k); - return -wi + 2.0f * wm * dot(wi, wm); } -ccl_device_forceinline float3 mf_eval_phase_glossy(const float3 w, const float lambda, const float3 wo, const float2 alpha, float3 *n, float3 *k) +ccl_device_forceinline float3 mf_eval_phase_glossy(const float3 w, const float lambda, const float3 wo, const float2 alpha) { if(w.z > 0.9999f) return make_float3(0.0f, 0.0f, 0.0f); @@ -123,30 +120,9 @@ ccl_device_forceinline float3 mf_eval_phase_glossy(const float3 w, const float l else phase *= D_ggx_aniso(wh, alpha); - if(n && k) { - /* Apply conductive fresnel term. */ - return phase * fresnel_conductor(dotW_WH, *n, *k); - } - return make_float3(phase, phase, phase); } -/* Phase function for rough lambertian diffuse surfaces. */ -ccl_device_forceinline float3 mf_sample_phase_diffuse(const float3 wm, const float randu, const float randv) -{ - float3 tm, bm; - make_orthonormals(wm, &tm, &bm); - - float2 disk = concentric_sample_disk(randu, randv); - return disk.x*tm + disk.y*bm + safe_sqrtf(1.0f - disk.x*disk.x - disk.y*disk.y)*wm; -} - -ccl_device_forceinline float3 mf_eval_phase_diffuse(const float3 w, const float3 wm) -{ - const float v = max(0.0f, dot(w, wm)) * M_1_PI_F; - return make_float3(v, v, v); -} - /* Phase function for dielectric transmissive materials, including both reflection and refraction according to the dielectric fresnel term. */ ccl_device_forceinline float3 mf_sample_phase_glass(const float3 wi, const float eta, const float3 wm, const float randV, bool *outside) { @@ -269,40 +245,69 @@ ccl_device_forceinline float mf_ggx_albedo(float r) return saturate(albedo); } +ccl_device_inline float mf_ggx_transmission_albedo(float a, float ior) +{ + if(ior < 1.0f) { + ior = 1.0f/ior; + } + a = saturate(a); + ior = clamp(ior, 1.0f, 3.0f); + float I_1 = 0.0476898f*expf(-0.978352f*(ior-0.65657f)*(ior-0.65657f)) - 0.033756f*ior + 0.993261f; + float R_1 = (((0.116991f*a - 0.270369f)*a + 0.0501366f)*a - 0.00411511f)*a + 1.00008f; + float I_2 = (((-2.08704f*ior + 26.3298f)*ior - 127.906f)*ior + 292.958f)*ior - 287.946f + 199.803f/(ior*ior) - 101.668f/(ior*ior*ior); + float R_2 = ((((5.3725f*a -24.9307f)*a + 22.7437f)*a - 3.40751f)*a + 0.0986325f)*a + 0.00493504f; + + return saturate(1.0f + I_2*R_2*0.0019127f - (1.0f - I_1)*(1.0f - R_1)*9.3205f); +} + ccl_device_forceinline float mf_ggx_pdf(const float3 wi, const float3 wo, const float alpha) { float D = D_ggx(normalize(wi+wo), alpha); float lambda = mf_lambda(wi, make_float2(alpha, alpha)); + float singlescatter = 0.25f * D / max((1.0f + lambda) * wi.z, 1e-7f); + + float multiscatter = wo.z * M_1_PI_F; + float albedo = mf_ggx_albedo(alpha); - return 0.25f * D / max((1.0f + lambda) * wi.z, 1e-7f) + (1.0f - albedo) * wo.z; + return albedo*singlescatter + (1.0f - albedo)*multiscatter; } ccl_device_forceinline float mf_ggx_aniso_pdf(const float3 wi, const float3 wo, const float2 alpha) { - return 0.25f * D_ggx_aniso(normalize(wi+wo), alpha) / ((1.0f + mf_lambda(wi, alpha)) * wi.z) + (1.0f - mf_ggx_albedo(sqrtf(alpha.x*alpha.y))) * wo.z; -} + float D = D_ggx_aniso(normalize(wi+wo), alpha); + float lambda = mf_lambda(wi, alpha); + float singlescatter = 0.25f * D / max((1.0f + lambda) * wi.z, 1e-7f); -ccl_device_forceinline float mf_diffuse_pdf(const float3 wo) -{ - return M_1_PI_F * wo.z; + float multiscatter = wo.z * M_1_PI_F; + + float albedo = mf_ggx_albedo(sqrtf(alpha.x*alpha.y)); + return albedo*singlescatter + (1.0f - albedo)*multiscatter; } ccl_device_forceinline float mf_glass_pdf(const float3 wi, const float3 wo, const float alpha, const float eta) { - float3 wh; - float fresnel; - if(wi.z*wo.z > 0.0f) { - wh = normalize(wi + wo); - fresnel = fresnel_dielectric_cos(dot(wi, wh), eta); - } - else { - wh = normalize(wi + wo*eta); - fresnel = 1.0f - fresnel_dielectric_cos(dot(wi, wh), eta); - } + bool reflective = (wi.z*wo.z > 0.0f); + + float wh_len; + float3 wh = normalize_len(wi + (reflective? wo : (wo*eta)), &wh_len); if(wh.z < 0.0f) wh = -wh; float3 r_wi = (wi.z < 0.0f)? -wi: wi; - return fresnel * max(0.0f, dot(r_wi, wh)) * D_ggx(wh, alpha) / ((1.0f + mf_lambda(r_wi, make_float2(alpha, alpha))) * r_wi.z) + fabsf(wo.z); + float lambda = mf_lambda(r_wi, make_float2(alpha, alpha)); + float D = D_ggx(wh, alpha); + float fresnel = fresnel_dielectric_cos(dot(r_wi, wh), eta); + + float multiscatter = fabsf(wo.z * M_1_PI_F); + if(reflective) { + float singlescatter = 0.25f * D / max((1.0f + lambda) * r_wi.z, 1e-7f); + float albedo = mf_ggx_albedo(alpha); + return fresnel * (albedo*singlescatter + (1.0f - albedo)*multiscatter); + } + else { + float singlescatter = fabsf(dot(r_wi, wh)*dot(wo, wh) * D * eta*eta / max((1.0f + lambda) * r_wi.z * wh_len*wh_len, 1e-7f)); + float albedo = mf_ggx_transmission_albedo(alpha, eta); + return (1.0f - fresnel) * (albedo*singlescatter + (1.0f - albedo)*multiscatter); + } } /* === Actual random walk implementations, one version of mf_eval and mf_sample per phase function. === */ @@ -315,13 +320,6 @@ ccl_device_forceinline float mf_glass_pdf(const float3 wi, const float3 wo, cons #define MF_MULTI_GLASS #include "kernel/closure/bsdf_microfacet_multi_impl.h" -/* The diffuse phase function is not implemented as a node yet. */ -#if 0 -#define MF_PHASE_FUNCTION diffuse -#define MF_MULTI_DIFFUSE -#include "kernel/closure/bsdf_microfacet_multi_impl.h" -#endif - #define MF_PHASE_FUNCTION glossy #define MF_MULTI_GLOSSY #include "kernel/closure/bsdf_microfacet_multi_impl.h" @@ -345,8 +343,9 @@ ccl_device int bsdf_microfacet_multi_ggx_common_setup(MicrofacetBsdf *bsdf) bsdf->extra->color.x = saturate(bsdf->extra->color.x); bsdf->extra->color.y = saturate(bsdf->extra->color.y); bsdf->extra->color.z = saturate(bsdf->extra->color.z); - - bsdf->type = CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID; + bsdf->extra->cspec0.x = saturate(bsdf->extra->cspec0.x); + bsdf->extra->cspec0.y = saturate(bsdf->extra->cspec0.y); + bsdf->extra->cspec0.z = saturate(bsdf->extra->cspec0.z); return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_NEEDS_LCG; } @@ -356,6 +355,22 @@ ccl_device int bsdf_microfacet_multi_ggx_aniso_setup(MicrofacetBsdf *bsdf) if(is_zero(bsdf->T)) bsdf->T = make_float3(1.0f, 0.0f, 0.0f); + bsdf->type = CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID; + + return bsdf_microfacet_multi_ggx_common_setup(bsdf); +} + +ccl_device int bsdf_microfacet_multi_ggx_aniso_fresnel_setup(MicrofacetBsdf *bsdf, const ShaderData *sd) +{ + if(is_zero(bsdf->T)) + bsdf->T = make_float3(1.0f, 0.0f, 0.0f); + + bsdf->type = CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID; + + float F0 = fresnel_dielectric_cos(1.0f, bsdf->ior); + float F = average(interpolate_fresnel_color(sd->I, bsdf->N, bsdf->ior, F0, bsdf->extra->cspec0)); + bsdf->sample_weight *= F; + return bsdf_microfacet_multi_ggx_common_setup(bsdf); } @@ -363,6 +378,30 @@ ccl_device int bsdf_microfacet_multi_ggx_setup(MicrofacetBsdf *bsdf) { bsdf->alpha_y = bsdf->alpha_x; + bsdf->type = CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID; + + return bsdf_microfacet_multi_ggx_common_setup(bsdf); +} + +ccl_device int bsdf_microfacet_multi_ggx_fresnel_setup(MicrofacetBsdf *bsdf, const ShaderData *sd) +{ + bsdf->alpha_y = bsdf->alpha_x; + + bsdf->type = CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID; + + float F0 = fresnel_dielectric_cos(1.0f, bsdf->ior); + float F = average(interpolate_fresnel_color(sd->I, bsdf->N, bsdf->ior, F0, bsdf->extra->cspec0)); + bsdf->sample_weight *= F; + + return bsdf_microfacet_multi_ggx_common_setup(bsdf); +} + +ccl_device int bsdf_microfacet_multi_ggx_refraction_setup(MicrofacetBsdf *bsdf) +{ + bsdf->alpha_y = bsdf->alpha_x; + + bsdf->type = CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID; + return bsdf_microfacet_multi_ggx_common_setup(bsdf); } @@ -378,6 +417,8 @@ ccl_device float3 bsdf_microfacet_multi_ggx_eval_reflect(const ShaderClosure *sc return make_float3(0.0f, 0.0f, 0.0f); } + bool use_fresnel = (bsdf->type == CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID); + bool is_aniso = (bsdf->alpha_x != bsdf->alpha_y); float3 X, Y, Z; Z = bsdf->N; @@ -393,7 +434,7 @@ ccl_device float3 bsdf_microfacet_multi_ggx_eval_reflect(const ShaderClosure *sc *pdf = mf_ggx_aniso_pdf(localI, localO, make_float2(bsdf->alpha_x, bsdf->alpha_y)); else *pdf = mf_ggx_pdf(localI, localO, bsdf->alpha_x); - return mf_eval_glossy(localI, localO, true, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, NULL, NULL); + return mf_eval_glossy(localI, localO, true, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior, use_fresnel, bsdf->extra->cspec0); } ccl_device int bsdf_microfacet_multi_ggx_sample(KernelGlobals *kg, 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_addr_space uint *lcg_state) @@ -407,9 +448,15 @@ ccl_device int bsdf_microfacet_multi_ggx_sample(KernelGlobals *kg, const ShaderC *omega_in = 2*dot(Z, I)*Z - I; *pdf = 1e6f; *eval = make_float3(1e6f, 1e6f, 1e6f); +#ifdef __RAY_DIFFERENTIALS__ + *domega_in_dx = (2 * dot(Z, dIdx)) * Z - dIdx; + *domega_in_dy = (2 * dot(Z, dIdy)) * Z - dIdy; +#endif return LABEL_REFLECT|LABEL_SINGULAR; } + bool use_fresnel = (bsdf->type == CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID); + bool is_aniso = (bsdf->alpha_x != bsdf->alpha_y); if(is_aniso) make_orthonormals_tangent(Z, bsdf->T, &X, &Y); @@ -419,7 +466,7 @@ ccl_device int bsdf_microfacet_multi_ggx_sample(KernelGlobals *kg, const ShaderC float3 localI = make_float3(dot(I, X), dot(I, Y), dot(I, Z)); float3 localO; - *eval = mf_sample_glossy(localI, &localO, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, NULL, NULL); + *eval = mf_sample_glossy(localI, &localO, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior, use_fresnel, bsdf->extra->cspec0); if(is_aniso) *pdf = mf_ggx_aniso_pdf(localI, localO, make_float2(bsdf->alpha_x, bsdf->alpha_y)); else @@ -427,6 +474,7 @@ ccl_device int bsdf_microfacet_multi_ggx_sample(KernelGlobals *kg, const ShaderC *eval *= *pdf; *omega_in = X*localO.x + Y*localO.y + Z*localO.z; + #ifdef __RAY_DIFFERENTIALS__ *domega_in_dx = (2 * dot(Z, dIdx)) * Z - dIdx; *domega_in_dy = (2 * dot(Z, dIdy)) * Z - dIdy; @@ -450,6 +498,27 @@ ccl_device int bsdf_microfacet_multi_ggx_glass_setup(MicrofacetBsdf *bsdf) return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_NEEDS_LCG; } +ccl_device int bsdf_microfacet_multi_ggx_glass_fresnel_setup(MicrofacetBsdf *bsdf, const ShaderData *sd) +{ + bsdf->alpha_x = clamp(bsdf->alpha_x, 1e-4f, 1.0f); + bsdf->alpha_y = bsdf->alpha_x; + bsdf->ior = max(0.0f, bsdf->ior); + bsdf->extra->color.x = saturate(bsdf->extra->color.x); + bsdf->extra->color.y = saturate(bsdf->extra->color.y); + bsdf->extra->color.z = saturate(bsdf->extra->color.z); + bsdf->extra->cspec0.x = saturate(bsdf->extra->cspec0.x); + bsdf->extra->cspec0.y = saturate(bsdf->extra->cspec0.y); + bsdf->extra->cspec0.z = saturate(bsdf->extra->cspec0.z); + + bsdf->type = CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID; + + float F0 = fresnel_dielectric_cos(1.0f, bsdf->ior); + float F = average(interpolate_fresnel_color(sd->I, bsdf->N, bsdf->ior, F0, bsdf->extra->cspec0)); + bsdf->sample_weight *= F; + + return SD_BSDF|SD_BSDF_HAS_EVAL|SD_BSDF_NEEDS_LCG; +} + ccl_device float3 bsdf_microfacet_multi_ggx_glass_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf, ccl_addr_space uint *lcg_state) { const MicrofacetBsdf *bsdf = (const MicrofacetBsdf*)sc; @@ -465,7 +534,7 @@ ccl_device float3 bsdf_microfacet_multi_ggx_glass_eval_transmit(const ShaderClos float3 localO = make_float3(dot(omega_in, X), dot(omega_in, Y), dot(omega_in, Z)); *pdf = mf_glass_pdf(localI, localO, bsdf->alpha_x, bsdf->ior); - return mf_eval_glass(localI, localO, false, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior); + return mf_eval_glass(localI, localO, false, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior, false, bsdf->extra->color); } ccl_device float3 bsdf_microfacet_multi_ggx_glass_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf, ccl_addr_space uint *lcg_state) { @@ -475,6 +544,8 @@ ccl_device float3 bsdf_microfacet_multi_ggx_glass_eval_reflect(const ShaderClosu return make_float3(0.0f, 0.0f, 0.0f); } + bool use_fresnel = (bsdf->type == CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID); + float3 X, Y, Z; Z = bsdf->N; make_orthonormals(Z, &X, &Y); @@ -483,7 +554,7 @@ ccl_device float3 bsdf_microfacet_multi_ggx_glass_eval_reflect(const ShaderClosu float3 localO = make_float3(dot(omega_in, X), dot(omega_in, Y), dot(omega_in, Z)); *pdf = mf_glass_pdf(localI, localO, bsdf->alpha_x, bsdf->ior); - return mf_eval_glass(localI, localO, true, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior); + return mf_eval_glass(localI, localO, true, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior, use_fresnel, bsdf->extra->cspec0); } ccl_device int bsdf_microfacet_multi_ggx_glass_sample(KernelGlobals *kg, 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_addr_space uint *lcg_state) @@ -525,12 +596,14 @@ ccl_device int bsdf_microfacet_multi_ggx_glass_sample(KernelGlobals *kg, const S } } + bool use_fresnel = (bsdf->type == CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID); + make_orthonormals(Z, &X, &Y); float3 localI = make_float3(dot(I, X), dot(I, Y), dot(I, Z)); float3 localO; - *eval = mf_sample_glass(localI, &localO, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior); + *eval = mf_sample_glass(localI, &localO, bsdf->extra->color, bsdf->alpha_x, bsdf->alpha_y, lcg_state, bsdf->ior, use_fresnel, bsdf->extra->cspec0); *pdf = mf_glass_pdf(localI, localO, bsdf->alpha_x, bsdf->ior); *eval *= *pdf; |