diff options
Diffstat (limited to 'intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h')
| -rw-r--r-- | intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h | 398 |
1 files changed, 201 insertions, 197 deletions
diff --git a/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h b/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h index 5d300ef6db5..79247ee8057 100644 --- a/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h +++ b/intern/cycles/kernel/closure/bsdf_microfacet_multi_impl.h @@ -25,247 +25,251 @@ * energy is used. In combination with MIS, that is enough to produce an unbiased result, although * the balance heuristic isn't necessarily optimal anymore. */ -ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_eval)( - float3 wi, - float3 wo, - const bool wo_outside, - const float3 color, - const float alpha_x, - const float alpha_y, - ccl_addr_space uint *lcg_state, - const float eta, - bool use_fresnel, - const float3 cspec0) +ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_eval)(float3 wi, + float3 wo, + const bool wo_outside, + const float3 color, + const float alpha_x, + const float alpha_y, + ccl_addr_space uint *lcg_state, + const float eta, + bool use_fresnel, + const float3 cspec0) { - /* Evaluating for a shallower incoming direction produces less noise, and the properties of the BSDF guarantee reciprocity. */ - bool swapped = false; + /* Evaluating for a shallower incoming direction produces less noise, and the properties of the BSDF guarantee reciprocity. */ + bool swapped = false; #ifdef MF_MULTI_GLASS - if(wi.z*wo.z < 0.0f) { - /* Glass transmission is a special case and requires the directions to change hemisphere. */ - if(-wo.z < wi.z) { - swapped = true; - float3 tmp = -wo; - wo = -wi; - wi = tmp; - } - } - else + if (wi.z * wo.z < 0.0f) { + /* Glass transmission is a special case and requires the directions to change hemisphere. */ + if (-wo.z < wi.z) { + swapped = true; + float3 tmp = -wo; + wo = -wi; + wi = tmp; + } + } + else #endif - if(wo.z < wi.z) { - swapped = true; - float3 tmp = wo; - wo = wi; - wi = tmp; - } + if (wo.z < wi.z) { + swapped = true; + float3 tmp = wo; + wo = wi; + wi = tmp; + } - if(wi.z < 1e-5f || (wo.z < 1e-5f && wo_outside) || (wo.z > -1e-5f && !wo_outside)) - return make_float3(0.0f, 0.0f, 0.0f); + if (wi.z < 1e-5f || (wo.z < 1e-5f && wo_outside) || (wo.z > -1e-5f && !wo_outside)) + return make_float3(0.0f, 0.0f, 0.0f); - const float2 alpha = make_float2(alpha_x, alpha_y); + const float2 alpha = make_float2(alpha_x, alpha_y); - float lambda_r = mf_lambda(-wi, alpha); - float shadowing_lambda = mf_lambda(wo_outside? wo: -wo, alpha); + float lambda_r = mf_lambda(-wi, alpha); + float shadowing_lambda = mf_lambda(wo_outside ? wo : -wo, alpha); - /* Analytically compute single scattering for lower noise. */ - float3 eval; - float3 throughput = make_float3(1.0f, 1.0f, 1.0f); - const float3 wh = normalize(wi+wo); + /* Analytically compute single scattering for lower noise. */ + float3 eval; + float3 throughput = make_float3(1.0f, 1.0f, 1.0f); + const float3 wh = normalize(wi + wo); #ifdef MF_MULTI_GLASS - eval = mf_eval_phase_glass(-wi, lambda_r, wo, wo_outside, alpha, eta); - if(wo_outside) - eval *= -lambda_r / (shadowing_lambda - lambda_r); - else - eval *= -lambda_r * beta(-lambda_r, shadowing_lambda+1.0f); -#else /* MF_MULTI_GLOSSY */ - const float G2 = 1.0f / (1.0f - (lambda_r + 1.0f) + shadowing_lambda); - float val = G2 * 0.25f / wi.z; - if(alpha.x == alpha.y) - val *= D_ggx(wh, alpha.x); - else - val *= D_ggx_aniso(wh, alpha); - eval = make_float3(val, val, val); + eval = mf_eval_phase_glass(-wi, lambda_r, wo, wo_outside, alpha, eta); + if (wo_outside) + eval *= -lambda_r / (shadowing_lambda - lambda_r); + else + eval *= -lambda_r * beta(-lambda_r, shadowing_lambda + 1.0f); +#else /* MF_MULTI_GLOSSY */ + const float G2 = 1.0f / (1.0f - (lambda_r + 1.0f) + shadowing_lambda); + float val = G2 * 0.25f / wi.z; + if (alpha.x == alpha.y) + val *= D_ggx(wh, alpha.x); + else + val *= D_ggx_aniso(wh, alpha); + eval = make_float3(val, val, val); #endif - float F0 = fresnel_dielectric_cos(1.0f, eta); - if(use_fresnel) { - throughput = interpolate_fresnel_color(wi, wh, eta, F0, cspec0); + float F0 = fresnel_dielectric_cos(1.0f, eta); + if (use_fresnel) { + throughput = interpolate_fresnel_color(wi, wh, eta, F0, cspec0); - eval *= throughput; - } + eval *= throughput; + } - float3 wr = -wi; - float hr = 1.0f; - float C1_r = 1.0f; - float G1_r = 0.0f; - bool outside = true; + float3 wr = -wi; + float hr = 1.0f; + float C1_r = 1.0f; + float G1_r = 0.0f; + bool outside = true; - for(int order = 0; order < 10; order++) { - /* Sample microfacet height. */ - float height_rand = lcg_step_float_addrspace(lcg_state); - if(!mf_sample_height(wr, &hr, &C1_r, &G1_r, &lambda_r, height_rand)) - break; - /* Sample microfacet normal. */ - float vndf_rand_y = lcg_step_float_addrspace(lcg_state); - float vndf_rand_x = lcg_step_float_addrspace(lcg_state); - float3 wm = mf_sample_vndf(-wr, alpha, vndf_rand_x, vndf_rand_y); + for (int order = 0; order < 10; order++) { + /* Sample microfacet height. */ + float height_rand = lcg_step_float_addrspace(lcg_state); + if (!mf_sample_height(wr, &hr, &C1_r, &G1_r, &lambda_r, height_rand)) + break; + /* Sample microfacet normal. */ + float vndf_rand_y = lcg_step_float_addrspace(lcg_state); + float vndf_rand_x = lcg_step_float_addrspace(lcg_state); + float3 wm = mf_sample_vndf(-wr, alpha, vndf_rand_x, vndf_rand_y); #ifdef MF_MULTI_GLASS - if(order == 0 && use_fresnel) { - /* Evaluate amount of scattering towards wo on this microfacet. */ - float3 phase; - if(outside) - phase = mf_eval_phase_glass(wr, lambda_r, wo, wo_outside, alpha, eta); - else - phase = mf_eval_phase_glass(wr, lambda_r, -wo, !wo_outside, alpha, 1.0f / eta); + if (order == 0 && use_fresnel) { + /* Evaluate amount of scattering towards wo on this microfacet. */ + float3 phase; + if (outside) + phase = mf_eval_phase_glass(wr, lambda_r, wo, wo_outside, alpha, eta); + else + phase = mf_eval_phase_glass(wr, lambda_r, -wo, !wo_outside, alpha, 1.0f / eta); - eval = throughput * phase * mf_G1(wo_outside ? wo : -wo, mf_C1((outside == wo_outside) ? hr : -hr), shadowing_lambda); - } + eval = throughput * phase * + mf_G1(wo_outside ? wo : -wo, + mf_C1((outside == wo_outside) ? hr : -hr), + shadowing_lambda); + } #endif - if(order > 0) { - /* Evaluate amount of scattering towards wo on this microfacet. */ - float3 phase; + if (order > 0) { + /* Evaluate amount of scattering towards wo on this microfacet. */ + float3 phase; #ifdef MF_MULTI_GLASS - if(outside) - phase = mf_eval_phase_glass(wr, lambda_r, wo, wo_outside, alpha, eta); - else - phase = mf_eval_phase_glass(wr, lambda_r, -wo, !wo_outside, alpha, 1.0f/eta); -#else /* MF_MULTI_GLOSSY */ - phase = mf_eval_phase_glossy(wr, lambda_r, wo, alpha) * throughput; + if (outside) + phase = mf_eval_phase_glass(wr, lambda_r, wo, wo_outside, alpha, eta); + else + phase = mf_eval_phase_glass(wr, lambda_r, -wo, !wo_outside, alpha, 1.0f / eta); +#else /* MF_MULTI_GLOSSY */ + phase = mf_eval_phase_glossy(wr, lambda_r, wo, alpha) * throughput; #endif - eval += throughput * phase * mf_G1(wo_outside? wo: -wo, mf_C1((outside == wo_outside)? hr: -hr), shadowing_lambda); - } - if(order+1 < 10) { - /* Bounce from the microfacet. */ + eval += throughput * phase * + mf_G1(wo_outside ? wo : -wo, + mf_C1((outside == wo_outside) ? hr : -hr), + shadowing_lambda); + } + if (order + 1 < 10) { + /* Bounce from the microfacet. */ #ifdef MF_MULTI_GLASS - bool next_outside; - float3 wi_prev = -wr; - float phase_rand = lcg_step_float_addrspace(lcg_state); - wr = mf_sample_phase_glass(-wr, outside? eta: 1.0f/eta, wm, phase_rand, &next_outside); - if(!next_outside) { - outside = !outside; - wr = -wr; - hr = -hr; - } + bool next_outside; + float3 wi_prev = -wr; + float phase_rand = lcg_step_float_addrspace(lcg_state); + wr = mf_sample_phase_glass(-wr, outside ? eta : 1.0f / eta, wm, phase_rand, &next_outside); + if (!next_outside) { + outside = !outside; + wr = -wr; + hr = -hr; + } - if(use_fresnel && !next_outside) { - throughput *= color; - } - else if(use_fresnel && order > 0) { - throughput *= interpolate_fresnel_color(wi_prev, wm, eta, F0, cspec0); - } -#else /* MF_MULTI_GLOSSY */ - if(use_fresnel && order > 0) { - throughput *= interpolate_fresnel_color(-wr, wm, eta, F0, cspec0); - } - wr = mf_sample_phase_glossy(-wr, &throughput, wm); + if (use_fresnel && !next_outside) { + throughput *= color; + } + else if (use_fresnel && order > 0) { + throughput *= interpolate_fresnel_color(wi_prev, wm, eta, F0, cspec0); + } +#else /* MF_MULTI_GLOSSY */ + if (use_fresnel && order > 0) { + throughput *= interpolate_fresnel_color(-wr, wm, eta, F0, cspec0); + } + wr = mf_sample_phase_glossy(-wr, &throughput, wm); #endif - lambda_r = mf_lambda(wr, alpha); + lambda_r = mf_lambda(wr, alpha); - if(!use_fresnel) - throughput *= color; + if (!use_fresnel) + throughput *= color; - C1_r = mf_C1(hr); - G1_r = mf_G1(wr, C1_r, lambda_r); - } - } + C1_r = mf_C1(hr); + G1_r = mf_G1(wr, C1_r, lambda_r); + } + } - if(swapped) - eval *= fabsf(wi.z / wo.z); - return eval; + if (swapped) + eval *= fabsf(wi.z / wo.z); + return eval; } /* Perform a random walk on the microsurface starting from wi, returning the direction in which the walk * escaped the surface in wo. The function returns the throughput between wi and wo. * Without reflection losses due to coloring or fresnel absorption in conductors, the sampling is optimal. */ -ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_sample)( - float3 wi, - float3 *wo, - const float3 color, - const float alpha_x, - const float alpha_y, - ccl_addr_space uint *lcg_state, - const float eta, - bool use_fresnel, - const float3 cspec0) +ccl_device_forceinline float3 MF_FUNCTION_FULL_NAME(mf_sample)(float3 wi, + float3 *wo, + const float3 color, + const float alpha_x, + const float alpha_y, + ccl_addr_space uint *lcg_state, + const float eta, + bool use_fresnel, + const float3 cspec0) { - const float2 alpha = make_float2(alpha_x, alpha_y); + const float2 alpha = make_float2(alpha_x, alpha_y); - float3 throughput = make_float3(1.0f, 1.0f, 1.0f); - float3 wr = -wi; - float lambda_r = mf_lambda(wr, alpha); - float hr = 1.0f; - float C1_r = 1.0f; - float G1_r = 0.0f; - bool outside = true; + float3 throughput = make_float3(1.0f, 1.0f, 1.0f); + float3 wr = -wi; + float lambda_r = mf_lambda(wr, alpha); + float hr = 1.0f; + float C1_r = 1.0f; + float G1_r = 0.0f; + bool outside = true; - float F0 = fresnel_dielectric_cos(1.0f, eta); - if(use_fresnel) { - throughput = interpolate_fresnel_color(wi, normalize(wi + wr), eta, F0, cspec0); - } + float F0 = fresnel_dielectric_cos(1.0f, eta); + if (use_fresnel) { + throughput = interpolate_fresnel_color(wi, normalize(wi + wr), eta, F0, cspec0); + } - int order; - for(order = 0; order < 10; order++) { - /* Sample microfacet height. */ - float height_rand = lcg_step_float_addrspace(lcg_state); - if(!mf_sample_height(wr, &hr, &C1_r, &G1_r, &lambda_r, height_rand)) { - /* The random walk has left the surface. */ - *wo = outside? wr: -wr; - return throughput; - } - /* Sample microfacet normal. */ - float vndf_rand_y = lcg_step_float_addrspace(lcg_state); - float vndf_rand_x = lcg_step_float_addrspace(lcg_state); - float3 wm = mf_sample_vndf(-wr, alpha, vndf_rand_x, vndf_rand_y); + int order; + for (order = 0; order < 10; order++) { + /* Sample microfacet height. */ + float height_rand = lcg_step_float_addrspace(lcg_state); + if (!mf_sample_height(wr, &hr, &C1_r, &G1_r, &lambda_r, height_rand)) { + /* The random walk has left the surface. */ + *wo = outside ? wr : -wr; + return throughput; + } + /* Sample microfacet normal. */ + float vndf_rand_y = lcg_step_float_addrspace(lcg_state); + float vndf_rand_x = lcg_step_float_addrspace(lcg_state); + float3 wm = mf_sample_vndf(-wr, alpha, vndf_rand_x, vndf_rand_y); - /* First-bounce color is already accounted for in mix weight. */ - if(!use_fresnel && order > 0) - throughput *= color; + /* First-bounce color is already accounted for in mix weight. */ + if (!use_fresnel && order > 0) + throughput *= color; - /* Bounce from the microfacet. */ + /* Bounce from the microfacet. */ #ifdef MF_MULTI_GLASS - bool next_outside; - float3 wi_prev = -wr; - float phase_rand = lcg_step_float_addrspace(lcg_state); - wr = mf_sample_phase_glass(-wr, outside? eta: 1.0f/eta, wm, phase_rand, &next_outside); - if(!next_outside) { - hr = -hr; - wr = -wr; - outside = !outside; - } + bool next_outside; + float3 wi_prev = -wr; + float phase_rand = lcg_step_float_addrspace(lcg_state); + wr = mf_sample_phase_glass(-wr, outside ? eta : 1.0f / eta, wm, phase_rand, &next_outside); + if (!next_outside) { + hr = -hr; + wr = -wr; + outside = !outside; + } - if(use_fresnel) { - if(!next_outside) { - throughput *= color; - } - else { - float3 t_color = interpolate_fresnel_color(wi_prev, wm, eta, F0, cspec0); + if (use_fresnel) { + if (!next_outside) { + throughput *= color; + } + else { + float3 t_color = interpolate_fresnel_color(wi_prev, wm, eta, F0, cspec0); - if(order == 0) - throughput = t_color; - else - throughput *= t_color; - } - } -#else /* MF_MULTI_GLOSSY */ - if(use_fresnel) { - float3 t_color = interpolate_fresnel_color(-wr, wm, eta, F0, cspec0); + if (order == 0) + throughput = t_color; + else + throughput *= t_color; + } + } +#else /* MF_MULTI_GLOSSY */ + if (use_fresnel) { + float3 t_color = interpolate_fresnel_color(-wr, wm, eta, F0, cspec0); - if(order == 0) - throughput = t_color; - else - throughput *= t_color; - } - wr = mf_sample_phase_glossy(-wr, &throughput, wm); + if (order == 0) + throughput = t_color; + else + throughput *= t_color; + } + wr = mf_sample_phase_glossy(-wr, &throughput, wm); #endif - /* Update random walk parameters. */ - lambda_r = mf_lambda(wr, alpha); - G1_r = mf_G1(wr, C1_r, lambda_r); - } - *wo = make_float3(0.0f, 0.0f, 1.0f); - return make_float3(0.0f, 0.0f, 0.0f); + /* Update random walk parameters. */ + lambda_r = mf_lambda(wr, alpha); + G1_r = mf_G1(wr, C1_r, lambda_r); + } + *wo = make_float3(0.0f, 0.0f, 1.0f); + return make_float3(0.0f, 0.0f, 0.0f); } #undef MF_MULTI_GLASS |