diff options
| author | Lukas Stockner <lukas.stockner@freenet.de> | 2016-10-30 00:47:30 +0300 |
|---|---|---|
| committer | Lukas Stockner <lukas.stockner@freenet.de> | 2016-10-30 13:31:28 +0300 |
| commit | 26bf230920cb9ca0aa9626430169967f9e120482 (patch) | |
| tree | 266e7e0939a6471db8af7086635cc4e914c85b06 /intern/cycles/kernel/split | |
| parent | ce785868a56a1446750f5af1779f7623ca462ec2 (diff) | |
Cycles: Add optional probabilistic termination of light samples based on their expected contribution
In scenes with many lights, some of them might have a very small contribution to some pixels, but the shadow rays are traced anyways.
To avoid that, this patch adds probabilistic termination to light samples - if the contribution before checking for shadowing is below a user-defined threshold, the sample will be discarded with probability (1 - (contribution / threshold)) and otherwise kept, but weighted more to remain unbiased.
This is the same approach that's also used in path termination based on length.
Note that the rendering remains unbiased with this option, it just adds a bit of noise - but if the setting is used moderately, the speedup gained easily outweighs the additional noise.
Reviewers: #cycles
Subscribers: sergey, brecht
Differential Revision: https://developer.blender.org/D2217
Diffstat (limited to 'intern/cycles/kernel/split')
| -rw-r--r-- | intern/cycles/kernel/split/kernel_direct_lighting.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/intern/cycles/kernel/split/kernel_direct_lighting.h b/intern/cycles/kernel/split/kernel_direct_lighting.h index 6ad736fc2c1..82ca18829d3 100644 --- a/intern/cycles/kernel/split/kernel_direct_lighting.h +++ b/intern/cycles/kernel/split/kernel_direct_lighting.h @@ -72,6 +72,7 @@ ccl_device char kernel_direct_lighting( float light_t = path_state_rng_1D(kg, rng, state, PRNG_LIGHT); float light_u, light_v; path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v); + float terminate = path_state_rng_light_termination(kg, rng, state); LightSample ls; if(light_sample(kg, @@ -88,7 +89,7 @@ ccl_device char kernel_direct_lighting( BsdfEval L_light; bool is_lamp; - if(direct_emission(kg, sd, kg->sd_input, &ls, state, &light_ray, &L_light, &is_lamp)) { + if(direct_emission(kg, sd, kg->sd_input, &ls, state, &light_ray, &L_light, &is_lamp, terminate)) { /* Write intermediate data to global memory to access from * the next kernel. */ |