diff options
Diffstat (limited to 'intern/cycles/kernel/kernel_volume.h')
| -rw-r--r-- | intern/cycles/kernel/kernel_volume.h | 176 |
1 files changed, 3 insertions, 173 deletions
diff --git a/intern/cycles/kernel/kernel_volume.h b/intern/cycles/kernel/kernel_volume.h index 495642af0f2..50e44b6b589 100644 --- a/intern/cycles/kernel/kernel_volume.h +++ b/intern/cycles/kernel/kernel_volume.h @@ -65,110 +65,6 @@ ccl_device float get_sigma_sample(KernelGlobals *kg, ShaderData *sd, int path_fl return sigma_from_value(v, 1.0f); } -ccl_device float3 kernel_volume_get_final_homogeneous_extinction_tsd(KernelGlobals *kg, ShaderData *sd, Ray ray, int path_flag, ShaderContext ctx) -{ - // return 3 transition extinction coefficients based on particle BRDF, base density and color - // make sense only for homogeneous volume for now - // the idea is to measure integral flux, not only individual free fly particles - // it help to get color gradients even with number of min/max bounces far from infinity - // NOTE: color must be constant as well, because we use it to modify extinction. - - float3 res_sigma = make_float3(1.0f, 1.0f, 1.0f); - if((sd->flag & SD_HAS_VOLUME) != 0) { // check for empty volume shader - // base sigma - float base_sigma = get_sigma_sample(kg, sd, path_flag, ctx, ray.P); - - // get transition probability - // or flux that pass forward even if catched by particle. - BsdfEval eval; - float3 omega_in = -sd->I; - float transition_pdf; - // FIXME: true only for g=0, need some weird integral for g != 0 cases. Sure not pdf directly, - // maybe lim(CPDF) when area -> omega_in ? Damn rocket science ... - shader_bsdf_eval(kg, sd, omega_in, &eval, &transition_pdf); -#if 0 - transition_pdf = single_peaked_henyey_greenstein(1.0f, 0.6); -#endif - - shader_eval_volume(kg, sd, 0.0f, path_flag, ctx); - - /* todo: this assumes global density and is broken, color is per closure! */ - int sampled = 0; - const ShaderClosure *sc = &sd->closure[sampled]; - float3 color = sc->weight; - -#if 1 -// res_sigma = make_float3(base_sigma, base_sigma, base_sigma) / ( make_float3(transition_pdf, transition_pdf, transition_pdf) * color); -// res_sigma = make_float3(base_sigma, base_sigma, base_sigma) * ( make_float3(transition_pdf, transition_pdf, transition_pdf) * color); -// float3 k = make_float3(1.0f, 1.0f, 1.0f) - (make_float3(transition_pdf, transition_pdf, transition_pdf) * color); -// res_sigma = make_float3(base_sigma, base_sigma, base_sigma) * k; -// float3 k = make_float3(1.0f, 1.0f, 1.0f) - (make_float3(transition_pdf, transition_pdf, transition_pdf) * color); -// float3 k = (make_float3(transition_pdf, transition_pdf, transition_pdf) * color); -// res_sigma = make_float3(base_sigma, base_sigma, base_sigma) - k; -// res_sigma.x = base_sigma * (1.0f + logf(1.0f - transition_pdf * color.x)); -// res_sigma.y = base_sigma * (1.0f + logf(1.0f - transition_pdf * color.y)); -// res_sigma.z = base_sigma * (1.0f + logf(1.0f - transition_pdf * color.z)); - res_sigma.x = base_sigma * (1.0f + logf(1.0f + (1.0f / M_E - 1.0f) * transition_pdf * color.x)); - res_sigma.y = base_sigma * (1.0f + logf(1.0f + (1.0f / M_E - 1.0f) * transition_pdf * color.y)); - res_sigma.z = base_sigma * (1.0f + logf(1.0f + (1.0f / M_E - 1.0f) * transition_pdf * color.z)); -// printf("pdf=%g\n", transition_pdf); -#else - res_sigma = (make_float3(transition_pdf, transition_pdf, transition_pdf) * color); - res_sigma = min(res_sigma, 1.0f); -#endif - } - - return res_sigma; -} - -/* unused */ -ccl_device float kernel_volume_homogeneous_pdf( KernelGlobals *kg, ShaderData *sd, ShaderContext ctx, float distance) -{ - /* todo: do we need path_flag? */ - float sigma = get_sigma_sample(kg, sd, 0, ctx, make_float3(0.0f, 0.0f, 0.0f)); - -#ifdef __VOLUME_USE_GUARANTEE_HIT_PROB - return sigma * exp(-distance * sigma) * VOLUME_GUARANTEE_HIT_PROB; -#else - return sigma * exp(-distance * sigma); -#endif -} - -ccl_device float3 kernel_volume_get_final_homogeneous_extinction(KernelGlobals *kg, ShaderContext ctx, int media_volume_shader) -{ - ShaderData tsd; - Ray ray; - ray.P = make_float3(0.0f, 0.0f, 0.0f); - ray.D = make_float3(0.0f, 0.0f, 1.0f); - ray.t = 0.0f; - shader_setup_from_volume(kg, &tsd, &ray, media_volume_shader); - int path_flag = PATH_RAY_SHADOW; // why ? - - float3 res_sigma = make_float3(1.0f, 1.0f, 1.0f); - if((tsd.flag & SD_HAS_VOLUME) != 0) { // check for empty volume shader - // base sigma - float base_sigma = get_sigma_sample(kg, &tsd, path_flag, ctx, ray.P); - - // get transition probability - BsdfEval eval; - float3 omega_in = -tsd.I; - float transition_pdf; - shader_bsdf_eval(kg, &tsd, omega_in, &eval, &transition_pdf); - - // colors - shader_eval_volume(kg, &tsd, 0.0f, path_flag, SHADER_CONTEXT_MAIN); - - /* todo: this assumes global density and is broken, color is per closure! */ - int sampled = 0; - const ShaderClosure *sc = &tsd.closure[sampled]; - float3 color = sc->weight; - - res_sigma = make_float3(base_sigma, base_sigma, base_sigma) / (make_float3(transition_pdf, transition_pdf, transition_pdf) * color); - } - - return res_sigma; -} - ccl_device int get_media_volume_shader(KernelGlobals *kg, float3 P, int bounce) { /* check all objects that intersect random ray from given point, assume we have perfect geometry (all meshes closed, correct faces direct @@ -436,7 +332,6 @@ ccl_device int kernel_volumetric_homogeneous_sampler(KernelGlobals *kg, float ra return 0; } -#if 1 if (omega_cache) { if(*omega_cache == 0.0f) { *omega_cache = get_sigma_sample(kg, sd, path_flag, ctx, ray.P); @@ -445,11 +340,6 @@ ccl_device int kernel_volumetric_homogeneous_sampler(KernelGlobals *kg, float ra } else sigma = get_sigma_sample(kg, sd, path_flag, ctx, ray.P); -#else - float3 sigma3 = kernel_volume_get_final_homogeneous_extinction_tsd(kg, sd, ray, path_flag, ctx); - sigma = min( sigma3.x, sigma3.y); - sigma = min( sigma, sigma3.z); -#endif if(sigma < SIGMA_MAGIC_EPS) { /* Very transparent volume - Protect div by 0, *new_t = end; */ @@ -635,46 +525,12 @@ ccl_device float3 kernel_volume_get_shadow_attenuation(KernelGlobals *kg, RNG *r attenuation = make_float3(1.0f, 1.0f, 1.0f); else { *volume_pdf = sigma * exp(-light_ray->t * sigma); -#if 0 - float a = exp(-light_ray->t * sigma); - attenuation = make_float3(a, a, a); -#else - // maybe it incorrect, but in homogeneous and constant color media we can analytically - // calculate transition color as well, based on knowledge of phase function probability - // in front direction, and integral of contributions of all possible combinations - // of direct light along straight line. - // (actually it only my guess, need to search correct integral, i assume it exp(-distance*sigma), - // remember we need complete unbiased multiscattering solution, not fake with 3 different color densities) - // In other words, try to calculate integral assuming Max Bounce = infinity along line. - // warning, require Color = constant as well as Homogeneous - // TODO: ensure that shader have color input unplugged. -// float3 color = make_float3(0.2f, 0.8f, 0.8f); -// float3 color = make_float3(0.5f, 0.99f, 0.99f); -// float3 tr_color = make_float3(1.0f, 1.0f, 1.0f) - color; -// float3 tr_color = color; -#if 0 - attenuation.x = exp(-light_ray->t * sigma / (transition_pdf * tr_color.x) ); - attenuation.y = exp(-light_ray->t * sigma / (transition_pdf * tr_color.y) ); - attenuation.z = exp(-light_ray->t * sigma / (transition_pdf * tr_color.z) ); -#else -// float3 sigma3 = kernel_volume_get_final_homogeneous_extinction_tsd(kg, &tsd, *light_ray, PATH_RAY_SHADOW, SHADER_CONTEXT_SHADOW); -#if 1 -// attenuation.x = exp(-light_ray->t * sigma3.x); -// attenuation.y = exp(-light_ray->t * sigma3.y); -// attenuation.z = exp(-light_ray->t * sigma3.z); + + /* todo: sigma should become a float3 with per color channel + * density returned by get_sigma_sample */ attenuation.x = exp(-light_ray->t * sigma); attenuation.y = exp(-light_ray->t * sigma); attenuation.z = exp(-light_ray->t * sigma); -#else -// attenuation.x = exp(-light_ray->t * sigma3.x) + exp(-light_ray->t * sigma); -// attenuation.y = exp(-light_ray->t * sigma3.y) + exp(-light_ray->t * sigma); -// attenuation.z = exp(-light_ray->t * sigma3.z) + exp(-light_ray->t * sigma); - attenuation.x = exp(-light_ray->t * sigma) + (1.0f - exp(-light_ray->t * sigma)) * sigma3.x; - attenuation.y = exp(-light_ray->t * sigma) + (1.0f - exp(-light_ray->t * sigma)) * sigma3.y; - attenuation.z = exp(-light_ray->t * sigma) + (1.0f - exp(-light_ray->t * sigma)) * sigma3.z; -#endif -#endif -#endif } } @@ -957,32 +813,6 @@ ccl_device int kernel_path_trace_volume(KernelGlobals *kg, RNG *rng, int rng_off *volume_eval = make_float3( eval, eval, eval); //*volume_eval = make_float3( *volume_pdf, *volume_pdf, *volume_pdf); // perfect importance sampling for homogeneous - // even if we missed any volume particle and hit face after it, we still modify color - // by transition attenuation, to respect "leaked" light because of scattering in strong forward direction - if (vsd.flag & SD_HOMOGENEOUS_VOLUME) - { - //int path_flag = 0; - - //float sigma = get_sigma_sample(kg, &vsd, randp, PATH_RAY_SHADOW, SHADER_CONTEXT_VOLUME, ray->P/* + ray.D * start*/); - //if (sigma < 0.0f) sigma = 0.0f; - //float3 sigma3 = kernel_volume_get_final_homogeneous_extinction_tsd(kg, &vsd, randp, *ray, path_flag, SHADER_CONTEXT_VOLUME); - //float3 attenuation; -// attenuation.x = exp(-isect_t* sigma3.x); -// attenuation.y = exp(-isect_t* sigma3.y); -// attenuation.z = exp(-isect_t* sigma3.z); -// bsdf_eval_mul(&bsdf_eval, attenuation); -// *throughput *= attenuation; -// *throughput += attenuation; -// attenuation.x = (1.0f - exp(-isect_t* sigma)) * sigma3.x; -// attenuation.y = (1.0f - exp(-isect_t* sigma)) * sigma3.y; -// attenuation.z = (1.0f - exp(-isect_t* sigma)) * sigma3.z; - //attenuation.x = exp(-isect_t* sigma3.x) - exp(-isect_t* sigma); - //attenuation.y = exp(-isect_t* sigma3.y) - exp(-isect_t* sigma); - //attenuation.z = exp(-isect_t* sigma3.z) - exp(-isect_t* sigma); -// *throughput *= (make_float3(1.0f, 1.0f, 1.0f) + attenuation); - //*volume_eval = make_float3( *volume_pdf, *volume_pdf, *volume_pdf); // perfect importance sampling for homogeneous - } - return VOLUME_PATH_PARTICLE_MISS; } |