diff options
Diffstat (limited to 'intern/cycles/kernel/integrator/subsurface_random_walk.h')
| -rw-r--r-- | intern/cycles/kernel/integrator/subsurface_random_walk.h | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/intern/cycles/kernel/integrator/subsurface_random_walk.h b/intern/cycles/kernel/integrator/subsurface_random_walk.h index 9c67d909bd4..a6a59e286c9 100644 --- a/intern/cycles/kernel/integrator/subsurface_random_walk.h +++ b/intern/cycles/kernel/integrator/subsurface_random_walk.h @@ -165,8 +165,7 @@ ccl_device_inline bool subsurface_random_walk(KernelGlobals kg, ccl_private Ray &ray, ccl_private LocalIntersection &ss_isect) { - float bssrdf_u, bssrdf_v; - path_state_rng_2D(kg, &rng_state, PRNG_BSDF_U, &bssrdf_u, &bssrdf_v); + const float2 rand_bsdf = path_state_rng_2D(kg, &rng_state, PRNG_SUBSURFACE_BSDF); const float3 P = INTEGRATOR_STATE(state, ray, P); const float3 N = INTEGRATOR_STATE(state, ray, D); @@ -179,7 +178,7 @@ ccl_device_inline bool subsurface_random_walk(KernelGlobals kg, /* Sample diffuse surface scatter into the object. */ float3 D; float pdf; - sample_cos_hemisphere(-N, bssrdf_u, bssrdf_v, &D, &pdf); + sample_cos_hemisphere(-N, rand_bsdf.x, rand_bsdf.y, &D, &pdf); if (dot(-Ng, D) <= 0.0f) { return false; } @@ -229,7 +228,7 @@ ccl_device_inline bool subsurface_random_walk(KernelGlobals kg, const float phase_log = logf((diffusion_length + 1.0f) / (diffusion_length - 1.0f)); /* Modify state for RNGs, decorrelated from other paths. */ - rng_state.rng_hash = cmj_hash(rng_state.rng_hash + rng_state.rng_offset, 0xdeadbeef); + rng_state.rng_hash = hash_hp_seeded_uint(rng_state.rng_hash + rng_state.rng_offset, 0xdeadbeef); /* Random walk until we hit the surface again. */ bool hit = false; @@ -272,11 +271,11 @@ ccl_device_inline bool subsurface_random_walk(KernelGlobals kg, #endif /* Sample color channel, use MIS with balance heuristic. */ - float rphase = path_state_rng_1D(kg, &rng_state, PRNG_PHASE_CHANNEL); + float rphase = path_state_rng_1D(kg, &rng_state, PRNG_SUBSURFACE_PHASE_CHANNEL); Spectrum channel_pdf; int channel = volume_sample_channel(alpha, throughput, rphase, &channel_pdf); float sample_sigma_t = volume_channel_get(sigma_t, channel); - float randt = path_state_rng_1D(kg, &rng_state, PRNG_SCATTER_DISTANCE); + float randt = path_state_rng_1D(kg, &rng_state, PRNG_SUBSURFACE_SCATTER_DISTANCE); /* We need the result of the ray-cast to compute the full guided PDF, so just remember the * relevant terms to avoid recomputing them later. */ @@ -289,7 +288,8 @@ ccl_device_inline bool subsurface_random_walk(KernelGlobals kg, /* For the initial ray, we already know the direction, so just do classic distance sampling. */ if (bounce > 0) { /* Decide whether we should use guided or classic sampling. */ - bool guided = (path_state_rng_1D(kg, &rng_state, PRNG_LIGHT_TERMINATE) < guided_fraction); + bool guided = (path_state_rng_1D(kg, &rng_state, PRNG_SUBSURFACE_GUIDE_STRATEGY) < + guided_fraction); /* Determine if we want to sample away from the incoming interface. * This only happens if we found a nearby opposite interface, and the probability for it @@ -303,27 +303,28 @@ ccl_device_inline bool subsurface_random_walk(KernelGlobals kg, float x = clamp(dot(ray.P - P, -N), 0.0f, opposite_distance); backward_fraction = 1.0f / (1.0f + expf((opposite_distance - 2.0f * x) / diffusion_length)); - guide_backward = path_state_rng_1D(kg, &rng_state, PRNG_TERMINATE) < backward_fraction; + guide_backward = path_state_rng_1D(kg, &rng_state, PRNG_SUBSURFACE_GUIDE_DIRECTION) < + backward_fraction; } /* Sample scattering direction. */ - float scatter_u, scatter_v; - path_state_rng_2D(kg, &rng_state, PRNG_BSDF_U, &scatter_u, &scatter_v); + const float2 rand_scatter = path_state_rng_2D(kg, &rng_state, PRNG_SUBSURFACE_BSDF); float cos_theta; float hg_pdf; if (guided) { - cos_theta = sample_phase_dwivedi(diffusion_length, phase_log, scatter_u); + cos_theta = sample_phase_dwivedi(diffusion_length, phase_log, rand_scatter.x); /* The backwards guiding distribution is just mirrored along `sd->N`, so swapping the * sign here is enough to sample from that instead. */ if (guide_backward) { cos_theta = -cos_theta; } - float3 newD = direction_from_cosine(N, cos_theta, scatter_v); + float3 newD = direction_from_cosine(N, cos_theta, rand_scatter.y); hg_pdf = single_peaked_henyey_greenstein(dot(ray.D, newD), anisotropy); ray.D = newD; } else { - float3 newD = henyey_greenstrein_sample(ray.D, anisotropy, scatter_u, scatter_v, &hg_pdf); + float3 newD = henyey_greenstrein_sample( + ray.D, anisotropy, rand_scatter.x, rand_scatter.y, &hg_pdf); cos_theta = dot(newD, N); ray.D = newD; } |