Cycles: Small optimization for scenes without Transparent Shaders, helps a few percent.

Differential Revision: https://developer.blender.org/D570

2 files changed, 12 insertions, 2 deletions

diff --git a/intern/cycles/render/integrator.cpp b/intern/cycles/render/integrator.cpp
index 59a0de07e5a..051ba1baf3a 100644
--- a/intern/cycles/render/integrator.cpp
+++ b/intern/cycles/render/integrator.cpp
@@ -95,7 +95,11 @@ void Integrator::device_update(Device *device, DeviceScene *dscene, Scene *scene
 	kintegrator->transparent_max_bounce = transparent_max_bounce + 1;
 	kintegrator->transparent_min_bounce = transparent_min_bounce + 1;
 
-	kintegrator->transparent_shadows = transparent_shadows;
+	/* At this point kintegrator->transparent_shadows is set automatically
+	 * based on whether shaders use transparent shadows (see shader.cpp).
+	 * If user doesn't want transparent shadows, force them off. */
+	if(!transparent_shadows)
+		kintegrator->transparent_shadows = false;
 
 	kintegrator->volume_homogeneous_sampling = volume_homogeneous_sampling;
 	kintegrator->volume_max_steps = volume_max_steps;
diff --git a/intern/cycles/render/shader.cpp b/intern/cycles/render/shader.cpp
index d48cd75d801..0f9a5a5d39d 100644
--- a/intern/cycles/render/shader.cpp
+++ b/intern/cycles/render/shader.cpp
@@ -229,6 +229,7 @@ void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Sc
 	uint i = 0;
 	bool has_converter_blackbody = false;
 	bool has_volumes = false;
+	bool has_transparent_shadows = false;
 
 	foreach(Shader *shader, scene->shaders) {
 		uint flag = 0;
@@ -267,6 +268,10 @@ void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Sc
 
 		shader_flag[i++] = flag;
 		shader_flag[i++] = shader->pass_id;
+		
+		/* Check if we need transparent shadows */
+		if(flag & SD_HAS_TRANSPARENT_SHADOW)
+			has_transparent_shadows = true;
 	}
 
 	device->tex_alloc("__shader_flag", dscene->shader_flag);
@@ -285,9 +290,10 @@ void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Sc
 		blackbody_table_offset = TABLE_OFFSET_INVALID;
 	}
 
-	/* volumes */
+	/* integrator */
 	KernelIntegrator *kintegrator = &dscene->data.integrator;
 	kintegrator->use_volumes = has_volumes;
+	kintegrator->transparent_shadows = has_transparent_shadows;
 }
 
 void ShaderManager::device_free_common(Device *device, DeviceScene *dscene, Scene *scene)