Cycles: add constant folding to displacement nodes.

2 files changed, 21 insertions, 0 deletions

diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index e36a75f59b1..d732189af66 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -5785,6 +5785,15 @@ DisplacementNode::DisplacementNode()
 {
 }
 
+void DisplacementNode::constant_fold(const ConstantFolder& folder)
+{
+	if(folder.all_inputs_constant()) {
+		if((height - midlevel == 0.0f) || (scale == 0.0f)) {
+			folder.make_zero();
+		}
+	}
+}
+
 void DisplacementNode::compile(SVMCompiler& compiler)
 {
 	ShaderInput *height_in = input("Height");
@@ -5836,6 +5845,16 @@ VectorDisplacementNode::VectorDisplacementNode()
 {
 }
 
+void VectorDisplacementNode::constant_fold(const ConstantFolder& folder)
+{
+	if(folder.all_inputs_constant()) {
+		if((vector == make_float3(0.0f, 0.0f, 0.0f) && midlevel == 0.0f) ||
+		   (scale == 0.0f)) {
+			folder.make_zero();
+		}
+	}
+}
+
 void VectorDisplacementNode::attributes(Shader *shader, AttributeRequestSet *attributes)
 {
 	if(shader->has_surface && space == NODE_NORMAL_MAP_TANGENT) {
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 33df2866341..58c3d472cd3 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -1063,6 +1063,7 @@ public:
 class DisplacementNode : public ShaderNode {
 public:
 	SHADER_NODE_CLASS(DisplacementNode)
+	void constant_fold(const ConstantFolder& folder);
 	virtual int get_feature() {
 		return NODE_FEATURE_BUMP;
 	}
@@ -1079,6 +1080,7 @@ public:
 	SHADER_NODE_CLASS(VectorDisplacementNode)
 	void attributes(Shader *shader, AttributeRequestSet *attributes);
 	bool has_attribute_dependency() { return true; }
+	void constant_fold(const ConstantFolder& folder);
 	virtual int get_feature() {
 		return NODE_FEATURE_BUMP;
 	}