1 files changed, 24 insertions, 7 deletions

diff --git a/intern/cycles/render/shader.cpp b/intern/cycles/render/shader.cpp
index 21bac460255..3c94f2dfb59 100644
--- a/intern/cycles/render/shader.cpp
+++ b/intern/cycles/render/shader.cpp
@@ -220,20 +220,37 @@ bool Shader::is_constant_emission(float3 *emission)
 {
 	ShaderInput *surf = graph->output()->input("Surface");
 
-	if(!surf->link || surf->link->parent->type != EmissionNode::node_type) {
+	if(surf->link == NULL) {
 		return false;
 	}
 
-	EmissionNode *node = (EmissionNode*) surf->link->parent;
+	if(surf->link->parent->type == EmissionNode::node_type) {
+		EmissionNode *node = (EmissionNode*) surf->link->parent;
 
-	assert(node->input("Color"));
-	assert(node->input("Strength"));
+		assert(node->input("Color"));
+		assert(node->input("Strength"));
 
-	if(node->input("Color")->link || node->input("Strength")->link) {
-		return false;
+		if(node->input("Color")->link || node->input("Strength")->link) {
+			return false;
+		}
+
+		*emission = node->color*node->strength;
 	}
+	else if(surf->link->parent->type == BackgroundNode::node_type) {
+		BackgroundNode *node = (BackgroundNode*) surf->link->parent;
 
-	*emission = node->color*node->strength;
+		assert(node->input("Color"));
+		assert(node->input("Strength"));
+
+		if(node->input("Color")->link || node->input("Strength")->link) {
+			return false;
+		}
+
+		*emission = node->color*node->strength;
+	}
+	else {
+		return false;
+	}
 
 	return true;
 }