Cycles: Optimize shaders earlier to skip unneccessary attributes for noninteractive rendering

Before, Cycles would first sync the shader exactly as shown in the UI, then determine and sync the used attributes and later optimize the shader.
Therefore, even completely unconnected nodes would cause unneccessary attributes to be synced.

The reason for this is to avoid frequent resyncs when editing shaders interactively, but it can still be avoided for noninteractive renders - which is what this commit does.

Reviewed by: sergey

Differential Revision: https://developer.blender.org/D2285

4 files changed, 23 insertions, 9 deletions

diff --git a/intern/cycles/render/graph.cpp b/intern/cycles/render/graph.cpp
index f6c83fb5c7e..0cfd08090c2 100644
--- a/intern/cycles/render/graph.cpp
+++ b/intern/cycles/render/graph.cpp
@@ -17,6 +17,7 @@
 #include "attribute.h"
 #include "graph.h"
 #include "nodes.h"
+#include "scene.h"
 #include "shader.h"
 #include "constant_fold.h"
 
@@ -195,6 +196,7 @@ bool ShaderNode::equals(const ShaderNode& other)
 ShaderGraph::ShaderGraph()
 {
 	finalized = false;
+	simplified = false;
 	num_node_ids = 0;
 	add(new OutputNode());
 }
@@ -207,6 +209,8 @@ ShaderGraph::~ShaderGraph()
 ShaderNode *ShaderGraph::add(ShaderNode *node)
 {
 	assert(!finalized);
+	simplified = false;
+
 	node->id = num_node_ids++;
 	nodes.push_back(node);
 	return node;
@@ -241,6 +245,7 @@ void ShaderGraph::connect(ShaderOutput *from, ShaderInput *to)
 {
 	assert(!finalized);
 	assert(from && to);
+	simplified = false;
 
 	if(to->link) {
 		fprintf(stderr, "Cycles shader graph connect: input already connected.\n");
@@ -273,6 +278,7 @@ void ShaderGraph::connect(ShaderOutput *from, ShaderInput *to)
 void ShaderGraph::disconnect(ShaderOutput *from)
 {
 	assert(!finalized);
+	simplified = false;
 
 	foreach(ShaderInput *sock, from->links) {
 		sock->link = NULL;
@@ -285,6 +291,7 @@ void ShaderGraph::disconnect(ShaderInput *to)
 {
 	assert(!finalized);
 	assert(to->link);
+	simplified = false;
 
 	ShaderOutput *from = to->link;
 
@@ -294,6 +301,8 @@ void ShaderGraph::disconnect(ShaderInput *to)
 
 void ShaderGraph::relink(ShaderNode *node, ShaderOutput *from, ShaderOutput *to)
 {
+	simplified = false;
+
 	/* Copy because disconnect modifies this list */
 	vector<ShaderInput*> outputs = from->links;
 
@@ -310,9 +319,19 @@ void ShaderGraph::relink(ShaderNode *node, ShaderOutput *from, ShaderOutput *to)
 	}
 }
 
+void ShaderGraph::simplify(Scene *scene)
+{
+	if(!simplified) {
+		default_inputs(scene->shader_manager->use_osl());
+		clean(scene);
+		refine_bump_nodes();
+
+		simplified = true;
+	}
+}
+
 void ShaderGraph::finalize(Scene *scene,
                            bool do_bump,
-                           bool do_osl,
                            bool do_simplify,
                            bool bump_in_object_space)
 {
@@ -322,9 +341,7 @@ void ShaderGraph::finalize(Scene *scene,
 	 * modified afterwards. */
 
 	if(!finalized) {
-		default_inputs(do_osl);
-		clean(scene);
-		refine_bump_nodes();
+		simplify(scene);
 
 		if(do_bump)
 			bump_from_displacement(bump_in_object_space);
diff --git a/intern/cycles/render/graph.h b/intern/cycles/render/graph.h
index 06524d3fa13..d22193d4e51 100644
--- a/intern/cycles/render/graph.h
+++ b/intern/cycles/render/graph.h
@@ -240,6 +240,7 @@ public:
 	list<ShaderNode*> nodes;
 	size_t num_node_ids;
 	bool finalized;
+	bool simplified;
 
 	ShaderGraph();
 	~ShaderGraph();
@@ -255,9 +256,9 @@ public:
 	void relink(ShaderNode *node, ShaderOutput *from, ShaderOutput *to);
 
 	void remove_proxy_nodes();
+	void simplify(Scene *scene);
 	void finalize(Scene *scene,
 	              bool do_bump = false,
-	              bool do_osl = false,
 	              bool do_simplify = false,
 	              bool bump_in_object_space = false);
 
diff --git a/intern/cycles/render/osl.cpp b/intern/cycles/render/osl.cpp
index 67b68e63cb2..68bd8d96bf9 100644
--- a/intern/cycles/render/osl.cpp
+++ b/intern/cycles/render/osl.cpp
@@ -1096,12 +1096,10 @@ void OSLCompiler::compile(Scene *scene, OSLGlobals *og, Shader *shader)
 		/* finalize */
 		shader->graph->finalize(scene,
 		                        false,
-		                        true,
 		                        shader->has_integrator_dependency);
 		if(shader->graph_bump) {
 			shader->graph_bump->finalize(scene,
 			                             true,
-			                             true,
 			                             shader->has_integrator_dependency,
 			                             shader->displacement_method == DISPLACE_BOTH);
 		}
diff --git a/intern/cycles/render/svm.cpp b/intern/cycles/render/svm.cpp
index 955b892f4c3..bbf14c24b56 100644
--- a/intern/cycles/render/svm.cpp
+++ b/intern/cycles/render/svm.cpp
@@ -813,7 +813,6 @@ void SVMCompiler::compile(Scene *scene,
 		scoped_timer timer((summary != NULL)? &summary->time_finalize: NULL);
 		shader->graph->finalize(scene,
 		                        false,
-		                        false,
 		                        shader->has_integrator_dependency);
 	}
 
@@ -821,7 +820,6 @@ void SVMCompiler::compile(Scene *scene,
 		scoped_timer timer((summary != NULL)? &summary->time_finalize_bump: NULL);
 		shader->graph_bump->finalize(scene,
 		                             true,
-		                             false,
 		                             shader->has_integrator_dependency,
 		                             shader->displacement_method == DISPLACE_BOTH);
 	}