Cycles: restore Denoising Depth pass, when enabling Denoising Data passes

This is still useful in some cases even if not used by OpenImageDenoise. In
the future this may be replaced with a more generic system to control render
passes and filtering, but for now this just does what it did before.

1 files changed, 8 insertions, 0 deletions

diff --git a/intern/cycles/kernel/kernel_passes.h b/intern/cycles/kernel/kernel_passes.h
index ab8d7a26f44..8ff7750c7d5 100644
--- a/intern/cycles/kernel/kernel_passes.h
+++ b/intern/cycles/kernel/kernel_passes.h
@@ -52,6 +52,14 @@ ccl_device_forceinline void kernel_write_denoising_features_surface(
 
   ccl_global float *buffer = kernel_pass_pixel_render_buffer(kg, state, render_buffer);
 
+  if (kernel_data.film.pass_denoising_depth != PASS_UNUSED) {
+    const float3 denoising_feature_throughput = INTEGRATOR_STATE(
+        state, path, denoising_feature_throughput);
+    const float denoising_depth = ensure_finite(average(denoising_feature_throughput) *
+                                                sd->ray_length);
+    kernel_write_pass_float(buffer + kernel_data.film.pass_denoising_depth, denoising_depth);
+  }
+
   float3 normal = zero_float3();
   float3 diffuse_albedo = zero_float3();
   float3 specular_albedo = zero_float3();