Cycles: Remove Bump Node from the graph, if Height input is not connected.

This way we can avoid building the split kernel with NODE_FEATURE_BUMP enabled, in case we don't need it.

intern/cycles/render/graph.cpp

@@ -419,6 +419,21 @@ void ShaderGraph::remove_unneeded_nodes()
 				}
 			}
 		}
+		else if(node->special_type == SHADER_SPECIAL_TYPE_BUMP) {
+			BumpNode *bump = static_cast<BumpNode*>(node);
+
+			if(bump->outputs[0]->links.size()) {
+				/* Height input not connected */
+				/* ToDo: Strength zero? */
+				if(!bump->inputs[0]->link) {
+					vector<ShaderInput*> inputs = bump->outputs[0]->links;
+
+					relink(bump->inputs, inputs, NULL);
+					removed[bump->id] = true;
+					any_node_removed = true;
+				}
+			}
+		}
 		else if(node->special_type == SHADER_SPECIAL_TYPE_MIX_CLOSURE) {
 			MixClosureNode *mix = static_cast<MixClosureNode*>(node);
 
@@ -560,7 +575,7 @@ void ShaderGraph::clean()
 		else
 			delete node;
 	}
-	
+
 	nodes = newnodes;
 }
 

intern/cycles/render/graph.h

@@ -84,6 +84,7 @@ enum ShaderNodeSpecialType {
 	SHADER_SPECIAL_TYPE_IMAGE_SLOT,
 	SHADER_SPECIAL_TYPE_CLOSURE,
 	SHADER_SPECIAL_TYPE_EMISSION,
+	SHADER_SPECIAL_TYPE_BUMP,
 };
 
 /* Enum

intern/cycles/render/nodes.cpp

@@ -3934,6 +3934,8 @@ BumpNode::BumpNode()
 {
 	invert = false;
 
+	special_type = SHADER_SPECIAL_TYPE_BUMP;
+
 	/* this input is used by the user, but after graph transform it is no longer
 	 * used and moved to sampler center/x/y instead */
 	add_input("Height", SHADER_SOCKET_FLOAT);

intern/cycles/render/nodes.h

@@ -652,7 +652,6 @@ public:
 	SHADER_NODE_CLASS(BumpNode)
 	bool has_spatial_varying() { return true; }
 	virtual int get_feature() {
-		/* TODO(sergey): Check for incoming links. */
 		return NODE_FEATURE_BUMP;
 	}