Commit: 74c65981ceb55ed8007be2ee8fd1dd7624c29b0c Author: Lukas Stockner Date: Wed Jun 8 03:17:19 2016 +0200 Branches: compositor-2016 https://developer.blender.org/rB74c65981ceb55ed8007be2ee8fd1dd7624c29b0c
Cycles: Fix two numerical issues in the volume code This hopefully fixes T48383 by avoiding two numerical problems that I found in the volume code. Reviewers: sergey, dingto, brecht Reviewed By: sergey, dingto, brecht Maniphest Tasks: T48383 Differential Revision: https://developer.blender.org/D2051 =================================================================== M intern/cycles/kernel/kernel_volume.h =================================================================== diff --git a/intern/cycles/kernel/kernel_volume.h b/intern/cycles/kernel/kernel_volume.h index 0e313b8..bf8301f 100644 --- a/intern/cycles/kernel/kernel_volume.h +++ b/intern/cycles/kernel/kernel_volume.h @@ -276,7 +276,7 @@ ccl_device float kernel_volume_distance_sample(float max_t, float3 sigma_t, int float sample_t = min(max_t, -logf(1.0f - xi*(1.0f - sample_transmittance))/sample_sigma_t); *transmittance = volume_color_transmittance(sigma_t, sample_t); - *pdf = (sigma_t * *transmittance)/(make_float3(1.0f, 1.0f, 1.0f) - full_transmittance); + *pdf = safe_divide_color(sigma_t * *transmittance, make_float3(1.0f, 1.0f, 1.0f) - full_transmittance); /* todo: optimization: when taken together with hit/miss decision, * the full_transmittance cancels out drops out and xi does not @@ -290,7 +290,7 @@ ccl_device float3 kernel_volume_distance_pdf(float max_t, float3 sigma_t, float float3 full_transmittance = volume_color_transmittance(sigma_t, max_t); float3 transmittance = volume_color_transmittance(sigma_t, sample_t); - return (sigma_t * transmittance)/(make_float3(1.0f, 1.0f, 1.0f) - full_transmittance); + return safe_divide_color(sigma_t * transmittance, make_float3(1.0f, 1.0f, 1.0f) - full_transmittance); } /* Emission */ @@ -625,11 +625,13 @@ ccl_device void kernel_volume_decoupled_record(KernelGlobals *kg, PathState *sta const int global_max_steps = kernel_data.integrator.volume_max_steps; step_size = kernel_data.integrator.volume_step_size; /* compute exact steps in advance for malloc */ - max_steps = max((int)ceilf(ray->t/step_size), 1); - if(max_steps > global_max_steps) { + if(ray->t > global_max_steps*step_size) { max_steps = global_max_steps; step_size = ray->t / (float)max_steps; } + else { + max_steps = max((int)ceilf(ray->t/step_size), 1); + } #ifdef __KERNEL_CPU__ /* NOTE: For the branched path tracing it's possible to have direct * and indirect light integration both having volume segments allocated. _______________________________________________ Bf-blender-cvs mailing list [email protected] https://lists.blender.org/mailman/listinfo/bf-blender-cvs
