From 223f45818ec216a76d89de0efcb3b0292eabf71e Mon Sep 17 00:00:00 2001 From: Mai Lavelle Date: Fri, 3 Mar 2017 04:07:26 -0500 Subject: [PATCH] Cycles: Initialize rng_state for split kernel Because the split kernel can render multiple samples in parallel it is necessary to have everything initialized before rendering of any samples begins. The code that normally handles initialization of `rng_state` (`kernel_path_trace_setup()`) only does so for the first sample, which was causing artifacts in the split kernel due to uninitialized `rng_state` for some samples. Note that because the split kernel can render samples in parallel this means that the split kernel is incompatible with the LCG. --- intern/cycles/kernel/split/kernel_data_init.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/intern/cycles/kernel/split/kernel_data_init.h b/intern/cycles/kernel/split/kernel_data_init.h index c22703e5abd..785103a79ac 100644 --- a/intern/cycles/kernel/split/kernel_data_init.h +++ b/intern/cycles/kernel/split/kernel_data_init.h @@ -126,7 +126,7 @@ void KERNEL_FUNCTION_FULL_NAME(data_init)( *use_queues_flag = 0; } - /* zero the tiles pixels if this is the first sample */ + /* zero the tiles pixels and initialize rng_state if this is the first sample */ if(start_sample == 0) { parallel_for(kg, i, sw * sh * kernel_data.film.pass_stride) { int pixel = i / kernel_data.film.pass_stride; @@ -139,6 +139,14 @@ void KERNEL_FUNCTION_FULL_NAME(data_init)( *(buffer + index) = 0.0f; } + + parallel_for(kg, i, sw * sh) { + int x = sx + i % sw; + int y = sy + i / sw; + + int index = (offset + x + y*stride); + *(rng_state + index) = hash_int_2d(x, y); + } } }