diff options
| -rw-r--r-- | intern/cycles/kernel/kernel_subsurface.h | 6 | ||||
| -rw-r--r-- | intern/cycles/kernel/kernel_volume.h | 24 |
2 files changed, 21 insertions, 9 deletions
diff --git a/intern/cycles/kernel/kernel_subsurface.h b/intern/cycles/kernel/kernel_subsurface.h index 55bbe7f95db..c75958e79c5 100644 --- a/intern/cycles/kernel/kernel_subsurface.h +++ b/intern/cycles/kernel/kernel_subsurface.h @@ -640,6 +640,12 @@ ccl_device_noinline /* If we hit the surface, we are done. */ break; } + else if (throughput.x < VOLUME_THROUGHPUT_EPSILON && + throughput.y < VOLUME_THROUGHPUT_EPSILON && + throughput.z < VOLUME_THROUGHPUT_EPSILON) { + /* Avoid unnecessary work and precision issue when throughput gets really small. */ + break; + } } kernel_assert(isfinite_safe(throughput.x) && isfinite_safe(throughput.y) && diff --git a/intern/cycles/kernel/kernel_volume.h b/intern/cycles/kernel/kernel_volume.h index 22a89997683..f6b34be040e 100644 --- a/intern/cycles/kernel/kernel_volume.h +++ b/intern/cycles/kernel/kernel_volume.h @@ -16,6 +16,12 @@ CCL_NAMESPACE_BEGIN +/* Ignore paths that have volume throughput below this value, to avoid unnecessary work + * and precision issues. + * todo: this value could be tweaked or turned into a probability to avoid unnecessary + * work in volumes and subsurface scattering. */ +#define VOLUME_THROUGHPUT_EPSILON 1e-6f + /* Events for probalistic scattering */ typedef enum VolumeIntegrateResult { @@ -226,7 +232,6 @@ ccl_device void kernel_volume_shadow_heterogeneous(KernelGlobals *kg, const float object_step_size) { float3 tp = *throughput; - const float tp_eps = 1e-6f; /* todo: this is likely not the right value */ /* Prepare for stepping. * For shadows we do not offset all segments, since the starting point is @@ -254,13 +259,15 @@ ccl_device void kernel_volume_shadow_heterogeneous(KernelGlobals *kg, /* compute attenuation over segment */ if (volume_shader_extinction_sample(kg, sd, state, new_P, &sigma_t)) { /* Compute expf() only for every Nth step, to save some calculations - * because exp(a)*exp(b) = exp(a+b), also do a quick tp_eps check then. */ + * because exp(a)*exp(b) = exp(a+b), also do a quick VOLUME_THROUGHPUT_EPSILON + * check then. */ sum += (-sigma_t * dt); if ((i & 0x07) == 0) { /* ToDo: Other interval? */ tp = *throughput * exp3(sum); /* stop if nearly all light is blocked */ - if (tp.x < tp_eps && tp.y < tp_eps && tp.z < tp_eps) + if (tp.x < VOLUME_THROUGHPUT_EPSILON && tp.y < VOLUME_THROUGHPUT_EPSILON && + tp.z < VOLUME_THROUGHPUT_EPSILON) break; } } @@ -572,7 +579,6 @@ kernel_volume_integrate_heterogeneous_distance(KernelGlobals *kg, const float object_step_size) { float3 tp = *throughput; - const float tp_eps = 1e-6f; /* todo: this is likely not the right value */ /* Prepare for stepping. * Using a different step offset for the first step avoids banding artifacts. */ @@ -669,7 +675,8 @@ kernel_volume_integrate_heterogeneous_distance(KernelGlobals *kg, tp = new_tp; /* stop if nearly all light blocked */ - if (tp.x < tp_eps && tp.y < tp_eps && tp.z < tp_eps) { + if (tp.x < VOLUME_THROUGHPUT_EPSILON && tp.y < VOLUME_THROUGHPUT_EPSILON && + tp.z < VOLUME_THROUGHPUT_EPSILON) { tp = zero_float3(); break; } @@ -770,8 +777,6 @@ ccl_device void kernel_volume_decoupled_record(KernelGlobals *kg, VolumeSegment *segment, const float object_step_size) { - const float tp_eps = 1e-6f; /* todo: this is likely not the right value */ - /* prepare for volume stepping */ int max_steps; float step_size, step_shade_offset, steps_offset; @@ -895,8 +900,9 @@ ccl_device void kernel_volume_decoupled_record(KernelGlobals *kg, break; /* stop if nearly all light blocked */ - if (accum_transmittance.x < tp_eps && accum_transmittance.y < tp_eps && - accum_transmittance.z < tp_eps) + if (accum_transmittance.x < VOLUME_THROUGHPUT_EPSILON && + accum_transmittance.y < VOLUME_THROUGHPUT_EPSILON && + accum_transmittance.z < VOLUME_THROUGHPUT_EPSILON) break; } |