Cycles: Query XYZ to/from Scene Linear conversion from OCIO instead of assuming sRGB

I've limited it to just the RGB<->XYZ stuff for now, correct image handling is the next step.

Reviewers: brecht, sergey

Differential Revision: https://developer.blender.org/D3478

32 files changed, 204 insertions, 65 deletions

diff --git a/intern/cycles/CMakeLists.txt b/intern/cycles/CMakeLists.txt
index 100a52625d1..233bc639fd8 100644
--- a/intern/cycles/CMakeLists.txt
+++ b/intern/cycles/CMakeLists.txt
@@ -326,6 +326,14 @@ if(WITH_CYCLES_NETWORK)
 	add_definitions(-DWITH_NETWORK)
 endif()
 
+if(WITH_OPENCOLORIO)
+	add_definitions(-DWITH_OCIO)
+	include_directories(
+		SYSTEM
+		${OPENCOLORIO_INCLUDE_DIRS}
+	)
+endif()
+
 if(WITH_CYCLES_STANDALONE OR WITH_CYCLES_NETWORK OR WITH_CYCLES_CUBIN_COMPILER)
 	add_subdirectory(app)
 endif()
diff --git a/intern/cycles/app/CMakeLists.txt b/intern/cycles/app/CMakeLists.txt
index d1f86a5fe7d..cfca45600a5 100644
--- a/intern/cycles/app/CMakeLists.txt
+++ b/intern/cycles/app/CMakeLists.txt
@@ -80,6 +80,10 @@ macro(cycles_target_link_libraries target)
 	if(WITH_CYCLES_OPENSUBDIV)
 		target_link_libraries(${target} ${OPENSUBDIV_LIBRARIES})
 	endif()
+	if(WITH_OPENCOLORIO)
+		link_directories(${OPENCOLORIO_LIBPATH})
+		target_link_libraries(${target} ${OPENCOLORIO_LIBRARIES})
+	endif()
 	target_link_libraries(
 		${target}
 		${OPENIMAGEIO_LIBRARIES}
diff --git a/intern/cycles/blender/blender_curves.cpp b/intern/cycles/blender/blender_curves.cpp
index 81d6a21cd13..5fd3455061d 100644
--- a/intern/cycles/blender/blender_curves.cpp
+++ b/intern/cycles/blender/blender_curves.cpp
@@ -784,17 +784,18 @@ static void ExportCurveTriangleVcol(ParticleCurveData *CData,
 
 			for(int curvekey = CData->curve_firstkey[curve]; curvekey < CData->curve_firstkey[curve] + CData->curve_keynum[curve] - 1; curvekey++) {
 				for(int section = 0; section < resol; section++) {
-					cdata[vertexindex] = color_float_to_byte(color_srgb_to_scene_linear_v3(CData->curve_vcol[curve]));
+					/* Encode vertex color using the sRGB curve. */
+					cdata[vertexindex] = color_float_to_byte(color_srgb_to_linear_v3(CData->curve_vcol[curve]));
 					vertexindex++;
-					cdata[vertexindex] = color_float_to_byte(color_srgb_to_scene_linear_v3(CData->curve_vcol[curve]));
+					cdata[vertexindex] = color_float_to_byte(color_srgb_to_linear_v3(CData->curve_vcol[curve]));
 					vertexindex++;
-					cdata[vertexindex] = color_float_to_byte(color_srgb_to_scene_linear_v3(CData->curve_vcol[curve]));
+					cdata[vertexindex] = color_float_to_byte(color_srgb_to_linear_v3(CData->curve_vcol[curve]));
 					vertexindex++;
-					cdata[vertexindex] = color_float_to_byte(color_srgb_to_scene_linear_v3(CData->curve_vcol[curve]));
+					cdata[vertexindex] = color_float_to_byte(color_srgb_to_linear_v3(CData->curve_vcol[curve]));
 					vertexindex++;
-					cdata[vertexindex] = color_float_to_byte(color_srgb_to_scene_linear_v3(CData->curve_vcol[curve]));
+					cdata[vertexindex] = color_float_to_byte(color_srgb_to_linear_v3(CData->curve_vcol[curve]));
 					vertexindex++;
-					cdata[vertexindex] = color_float_to_byte(color_srgb_to_scene_linear_v3(CData->curve_vcol[curve]));
+					cdata[vertexindex] = color_float_to_byte(color_srgb_to_linear_v3(CData->curve_vcol[curve]));
 					vertexindex++;
 				}
 			}
@@ -1010,9 +1011,10 @@ void BlenderSync::sync_curves(Mesh *mesh,
 				if(fdata) {
 					size_t i = 0;
 
+					/* Encode vertex color using the sRGB curve. */
 					for(size_t curve = 0; curve < CData.curve_vcol.size(); curve++)
 						if(!(CData.curve_keynum[curve] <= 1 || CData.curve_length[curve] == 0.0f))
-							fdata[i++] = color_srgb_to_scene_linear_v3(CData.curve_vcol[curve]);
+							fdata[i++] = color_srgb_to_linear_v3(CData.curve_vcol[curve]);
 				}
 			}
 		}
diff --git a/intern/cycles/blender/blender_mesh.cpp b/intern/cycles/blender/blender_mesh.cpp
index 76d17bc1ae6..8d2ade1e30b 100644
--- a/intern/cycles/blender/blender_mesh.cpp
+++ b/intern/cycles/blender/blender_mesh.cpp
@@ -401,7 +401,8 @@ static void attr_create_vertex_color(Scene *scene,
 				int n = p->loop_total();
 				for(int i = 0; i < n; i++) {
 					float3 color = get_float3(l->data[p->loop_start() + i].color());
-					*(cdata++) = color_float_to_byte(color_srgb_to_scene_linear_v3(color));
+					/* Encode vertex color using the sRGB curve. */
+					*(cdata++) = color_float_to_byte(color_srgb_to_linear_v3(color));
 				}
 			}
 		}
@@ -424,12 +425,13 @@ static void attr_create_vertex_color(Scene *scene,
 				int tri_a[3], tri_b[3];
 				face_split_tri_indices(face_flags[i], tri_a, tri_b);
 
+				/* Encode vertex color using the sRGB curve. */
 				uchar4 colors[4];
-				colors[0] = color_float_to_byte(color_srgb_to_scene_linear_v3(get_float3(c->color1())));
-				colors[1] = color_float_to_byte(color_srgb_to_scene_linear_v3(get_float3(c->color2())));
-				colors[2] = color_float_to_byte(color_srgb_to_scene_linear_v3(get_float3(c->color3())));
+				colors[0] = color_float_to_byte(color_srgb_to_linear_v3(get_float3(c->color1())));
+				colors[1] = color_float_to_byte(color_srgb_to_linear_v3(get_float3(c->color2())));
+				colors[2] = color_float_to_byte(color_srgb_to_linear_v3(get_float3(c->color3())));
 				if(nverts[i] == 4) {
-					colors[3] = color_float_to_byte(color_srgb_to_scene_linear_v3(get_float3(c->color4())));
+					colors[3] = color_float_to_byte(color_srgb_to_linear_v3(get_float3(c->color4())));
 				}
 
 				cdata[0] = colors[tri_a[0]];
diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index 00d23b9095e..4affd0479b0 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -139,6 +139,10 @@ void BlenderSession::create_session()
 	scene->image_manager->builtin_image_pixels_cb = function_bind(&BlenderSession::builtin_image_pixels, this, _1, _2, _3, _4, _5);
 	scene->image_manager->builtin_image_float_pixels_cb = function_bind(&BlenderSession::builtin_image_float_pixels, this, _1, _2, _3, _4, _5);
 
+#ifdef WITH_OCIO
+	scene->film->set_color_config(OCIO_getCurrentConfig());
+#endif
+
 	session->scene = scene;
 
 	/* create sync */
diff --git a/intern/cycles/cmake/external_libs.cmake b/intern/cycles/cmake/external_libs.cmake
index 8d04025e6fd..2e386a6bfc5 100644
--- a/intern/cycles/cmake/external_libs.cmake
+++ b/intern/cycles/cmake/external_libs.cmake
@@ -98,6 +98,12 @@ if(CYCLES_STANDALONE_REPOSITORY)
 	endif()
 
 	####
+	# OpenColorIO
+	if(WITH_OPENCOLORIO)
+		find_package(OpenColorIO REQUIRED)
+	endif()
+
+	####
 	# Boost
 	set(__boost_packages filesystem regex system thread date_time)
 	if(WITH_CYCLES_NETWORK)
diff --git a/intern/cycles/kernel/kernel_color.h b/intern/cycles/kernel/kernel_color.h
new file mode 100644
index 00000000000..d1c3dac824d
--- /dev/null
+++ b/intern/cycles/kernel/kernel_color.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2011-2018 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __KERNEL_COLOR_H__
+#define __KERNEL_COLOR_H__
+
+#include "util/util_color.h"
+
+CCL_NAMESPACE_BEGIN
+
+ccl_device float3 xyz_to_rgb(KernelGlobals *kg, float3 xyz)
+{
+    return make_float3(dot(kernel_data.film.xyz_to_r, xyz),
+                       dot(kernel_data.film.xyz_to_g, xyz),
+                       dot(kernel_data.film.xyz_to_b, xyz));
+}
+
+ccl_device float linear_rgb_to_gray(KernelGlobals *kg, float3 c)
+{
+    return dot(c, kernel_data.film.rgb_to_y);
+}
+
+CCL_NAMESPACE_END
+
+#endif /* __KERNEL_COLOR_H__ */
\ No newline at end of file
diff --git a/intern/cycles/kernel/kernel_film.h b/intern/cycles/kernel/kernel_film.h
index f9e9b413898..94815601179 100644
--- a/intern/cycles/kernel/kernel_film.h
+++ b/intern/cycles/kernel/kernel_film.h
@@ -22,9 +22,9 @@ ccl_device float4 film_map(KernelGlobals *kg, float4 irradiance, float scale)
 	float4 result = irradiance*scale;
 
 	/* conversion to srgb */
-	result.x = color_scene_linear_to_srgb(result.x*exposure);
-	result.y = color_scene_linear_to_srgb(result.y*exposure);
-	result.z = color_scene_linear_to_srgb(result.z*exposure);
+	result.x = color_linear_to_srgb(result.x*exposure);
+	result.y = color_linear_to_srgb(result.y*exposure);
+	result.z = color_linear_to_srgb(result.z*exposure);
 
 	/* clamp since alpha might be > 1.0 due to russian roulette */
 	result.w = saturate(result.w);
diff --git a/intern/cycles/kernel/kernel_types.h b/intern/cycles/kernel/kernel_types.h
index 5382213e6f7..633518c7926 100644
--- a/intern/cycles/kernel/kernel_types.h
+++ b/intern/cycles/kernel/kernel_types.h
@@ -1272,6 +1272,11 @@ typedef struct KernelFilm {
 	int pass_denoising_clean;
 	int denoising_flags;
 
+	float3 xyz_to_r;
+	float3 xyz_to_g;
+	float3 xyz_to_b;
+	float3 rgb_to_y;
+
 	int pad1, pad2, pad3;
 
 #ifdef __KERNEL_DEBUG__
diff --git a/intern/cycles/kernel/kernels/cpu/kernel_cpu_impl.h b/intern/cycles/kernel/kernels/cpu/kernel_cpu_impl.h
index ccca023a15f..5ec1655ab05 100644
--- a/intern/cycles/kernel/kernels/cpu/kernel_cpu_impl.h
+++ b/intern/cycles/kernel/kernels/cpu/kernel_cpu_impl.h
@@ -30,6 +30,7 @@
 #    include "kernel/split/kernel_split_data.h"
 #    include "kernel/kernel_globals.h"
 
+#    include "kernel/kernel_color.h"
 #    include "kernel/kernels/cpu/kernel_cpu_image.h"
 #    include "kernel/kernel_film.h"
 #    include "kernel/kernel_path.h"
diff --git a/intern/cycles/kernel/kernels/cuda/kernel.cu b/intern/cycles/kernel/kernels/cuda/kernel.cu
index 3c93e00ccf1..8a180a509e8 100644
--- a/intern/cycles/kernel/kernels/cuda/kernel.cu
+++ b/intern/cycles/kernel/kernels/cuda/kernel.cu
@@ -26,6 +26,7 @@
 #include "kernel/kernel_math.h"
 #include "kernel/kernel_types.h"
 #include "kernel/kernel_globals.h"
+#include "kernel/kernel_color.h"
 #include "kernel/kernels/cuda/kernel_cuda_image.h"
 #include "kernel/kernel_film.h"
 #include "kernel/kernel_path.h"
diff --git a/intern/cycles/kernel/kernels/opencl/kernel.cl b/intern/cycles/kernel/kernels/opencl/kernel.cl
index 9d5d784e140..63128d0aecf 100644
--- a/intern/cycles/kernel/kernels/opencl/kernel.cl
+++ b/intern/cycles/kernel/kernels/opencl/kernel.cl
@@ -20,6 +20,7 @@
 #include "kernel/kernel_math.h"
 #include "kernel/kernel_types.h"
 #include "kernel/kernel_globals.h"
+#include "kernel/kernel_color.h"
 #include "kernel/kernels/opencl/kernel_opencl_image.h"
 
 #include "kernel/kernel_film.h"
diff --git a/intern/cycles/kernel/osl/osl_services.cpp b/intern/cycles/kernel/osl/osl_services.cpp
index 5f4baf6fda3..1aca54d2ad5 100644
--- a/intern/cycles/kernel/osl/osl_services.cpp
+++ b/intern/cycles/kernel/osl/osl_services.cpp
@@ -41,6 +41,7 @@
 #include "kernel/kernel_compat_cpu.h"
 #include "kernel/split/kernel_split_data_types.h"
 #include "kernel/kernel_globals.h"
+#include "kernel/kernel_color.h"
 #include "kernel/kernel_random.h"
 #include "kernel/kernel_projection.h"
 #include "kernel/kernel_differential.h"
diff --git a/intern/cycles/kernel/shaders/node_color.h b/intern/cycles/kernel/shaders/node_color.h
index 4a17286a07f..2c3a810cb18 100644
--- a/intern/cycles/kernel/shaders/node_color.h
+++ b/intern/cycles/kernel/shaders/node_color.h
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+/* TODO(lukas): Fix colors in OSL. */
+
 float color_srgb_to_scene_linear(float c)
 {
 	if (c < 0.04045)
diff --git a/intern/cycles/kernel/split/kernel_split_common.h b/intern/cycles/kernel/split/kernel_split_common.h
index abe68104449..4b86696691a 100644
--- a/intern/cycles/kernel/split/kernel_split_common.h
+++ b/intern/cycles/kernel/split/kernel_split_common.h
@@ -23,6 +23,7 @@
 #include "kernel/split/kernel_split_data.h"
 
 #include "kernel/kernel_globals.h"
+#include "kernel/kernel_color.h"
 
 #ifdef __OSL__
 #  include "kernel/osl/osl_shader.h"
diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index bfa146f2d93..ce2affe96c8 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -243,7 +243,7 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ccl_a
 				svm_node_geometry(kg, sd, stack, node.y, node.z);
 				break;
 			case NODE_CONVERT:
-				svm_node_convert(sd, stack, node.y, node.z, node.w);
+				svm_node_convert(kg, sd, stack, node.y, node.z, node.w);
 				break;
 			case NODE_TEX_COORD:
 				svm_node_tex_coord(kg, sd, path_flag, stack, node, &offset);
@@ -465,7 +465,7 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg, ShaderData *sd, ccl_a
 				svm_node_wireframe(kg, sd, stack, node);
 				break;
 			case NODE_WAVELENGTH:
-				svm_node_wavelength(sd, stack, node.y, node.z);
+				svm_node_wavelength(kg, sd, stack, node.y, node.z);
 				break;
 			case NODE_BLACKBODY:
 				svm_node_blackbody(kg, sd, stack, node.y, node.z);
diff --git a/intern/cycles/kernel/svm/svm_closure.h b/intern/cycles/kernel/svm/svm_closure.h
index 886a1333fa3..76464e37c66 100644
--- a/intern/cycles/kernel/svm/svm_closure.h
+++ b/intern/cycles/kernel/svm/svm_closure.h
@@ -217,7 +217,7 @@ ccl_device void svm_node_closure_bsdf(KernelGlobals *kg, ShaderData *sd, float *
 
 			/* sheen */
 			if(diffuse_weight > CLOSURE_WEIGHT_CUTOFF && sheen > CLOSURE_WEIGHT_CUTOFF) {
-				float m_cdlum = linear_rgb_to_gray(base_color);
+				float m_cdlum = linear_rgb_to_gray(kg, base_color);
 				float3 m_ctint = m_cdlum > 0.0f ? base_color / m_cdlum : make_float3(1.0f, 1.0f, 1.0f); // normalize lum. to isolate hue+sat
 
 				/* color of the sheen component */
diff --git a/intern/cycles/kernel/svm/svm_convert.h b/intern/cycles/kernel/svm/svm_convert.h
index 34080377083..c88ac57e20d 100644
--- a/intern/cycles/kernel/svm/svm_convert.h
+++ b/intern/cycles/kernel/svm/svm_convert.h
@@ -18,7 +18,7 @@ CCL_NAMESPACE_BEGIN
 
 /* Conversion Nodes */
 
-ccl_device void svm_node_convert(ShaderData *sd, float *stack, uint type, uint from, uint to)
+ccl_device void svm_node_convert(KernelGlobals *kg, ShaderData *sd, float *stack, uint type, uint from, uint to)
 {
 	switch(type) {
 		case NODE_CONVERT_FI: {
@@ -33,13 +33,13 @@ ccl_device void svm_node_convert(ShaderData *sd, float *stack, uint type, uint f
 		}
 		case NODE_CONVERT_CF: {
 			float3 f = stack_load_float3(stack, from);
-			float g = linear_rgb_to_gray(f);
+			float g = linear_rgb_to_gray(kg, f);
 			stack_store_float(stack, to, g);
 			break;
 		}
 		case NODE_CONVERT_CI: {
 			float3 f = stack_load_float3(stack, from);
-			int i = (int)linear_rgb_to_gray(f);
+			int i = (int)linear_rgb_to_gray(kg, f);
 			stack_store_int(stack, to, i);
 			break;
 		}
diff --git a/intern/cycles/kernel/svm/svm_image.h b/intern/cycles/kernel/svm/svm_image.h
index 4226e7adfe0..28565308867 100644
--- a/intern/cycles/kernel/svm/svm_image.h
+++ b/intern/cycles/kernel/svm/svm_image.h
@@ -33,7 +33,8 @@ ccl_device float4 svm_image_texture(KernelGlobals *kg, int id, float x, float y,
 	}
 
 	if(srgb) {
-		r = color_srgb_to_scene_linear_v4(r);
+		/* TODO(lukas): Implement proper conversion for image textures. */
+		r = color_srgb_to_linear_v4(r);
 	}
 
 	return r;
diff --git a/intern/cycles/kernel/svm/svm_math_util.h b/intern/cycles/kernel/svm/svm_math_util.h
index 8e6bc73ddc7..caf0addbf35 100644
--- a/intern/cycles/kernel/svm/svm_math_util.h
+++ b/intern/cycles/kernel/svm/svm_math_util.h
@@ -138,6 +138,8 @@ ccl_static_constant float blackbody_table_b[6][4] = {
 
 ccl_device float3 svm_math_blackbody_color(float t)
 {
+	/* TODO(lukas): Reimplement in XYZ. */
+
 	if(t >= 12000.0f) {
 		return make_float3(0.826270103f, 0.994478524f, 1.56626022f);
 	}
diff --git a/intern/cycles/kernel/svm/svm_sky.h b/intern/cycles/kernel/svm/svm_sky.h
index 854e85fd326..b83a7168541 100644
--- a/intern/cycles/kernel/svm/svm_sky.h
+++ b/intern/cycles/kernel/svm/svm_sky.h
@@ -59,7 +59,7 @@ ccl_device float3 sky_radiance_old(KernelGlobals *kg, float3 dir,
 
 	/* convert to RGB */
 	float3 xyz = xyY_to_xyz(x, y, Y);
-	return xyz_to_rgb(xyz.x, xyz.y, xyz.z);
+	return xyz_to_rgb(kg, xyz);
 }
 
 /*
@@ -102,7 +102,7 @@ ccl_device float3 sky_radiance_new(KernelGlobals *kg, float3 dir,
 	float z = sky_radiance_internal(config_z, theta, gamma) * radiance_z;
 
 	/* convert to RGB and adjust strength */
-	return xyz_to_rgb(x, y, z) * (M_2PI_F/683);
+	return xyz_to_rgb(kg, make_float3(x, y, z)) * (M_2PI_F/683);
 }
 
 ccl_device void svm_node_tex_sky(KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node, int *offset)
diff --git a/intern/cycles/kernel/svm/svm_wavelength.h b/intern/cycles/kernel/svm/svm_wavelength.h
index 855b356b397..62e026278ac 100644
--- a/intern/cycles/kernel/svm/svm_wavelength.h
+++ b/intern/cycles/kernel/svm/svm_wavelength.h
@@ -70,7 +70,7 @@ ccl_static_constant float cie_colour_match[81][3] = {
 	{0.0001f,0.0000f,0.0000f}, {0.0001f,0.0000f,0.0000f}, {0.0000f,0.0000f,0.0000f}
 };
 
-ccl_device void svm_node_wavelength(ShaderData *sd, float *stack, uint wavelength, uint color_out)
+ccl_device void svm_node_wavelength(KernelGlobals *kg, ShaderData *sd, float *stack, uint wavelength, uint color_out)
 {	
 	float lambda_nm = stack_load_float(stack, wavelength);
 	float ii = (lambda_nm-380.0f) * (1.0f/5.0f);  // scaled 0..80
@@ -86,7 +86,7 @@ ccl_device void svm_node_wavelength(ShaderData *sd, float *stack, uint wavelengt
 		color = interp(make_float3(c[0], c[1], c[2]), make_float3(c[3], c[4], c[5]), ii);
 	}
 	
-	color = xyz_to_rgb(color.x, color.y, color.z);
+	color = xyz_to_rgb(kg, color);
 	color *= 1.0f/2.52f;	// Empirical scale from lg to make all comps <= 1
 	
 	/* Clamp to zero if values are smaller */
diff --git a/intern/cycles/render/constant_fold.cpp b/intern/cycles/render/constant_fold.cpp
index 943b218f0e4..98c3e99996c 100644
--- a/intern/cycles/render/constant_fold.cpp
+++ b/intern/cycles/render/constant_fold.cpp
@@ -22,8 +22,8 @@
 
 CCL_NAMESPACE_BEGIN
 
-ConstantFolder::ConstantFolder(ShaderGraph *graph, ShaderNode *node, ShaderOutput *output)
-: graph(graph), node(node), output(output)
+ConstantFolder::ConstantFolder(ShaderGraph *graph, ShaderNode *node, ShaderOutput *output, Scene *scene)
+: graph(graph), node(node), output(output), scene(scene)
 {
 }
 
diff --git a/intern/cycles/render/constant_fold.h b/intern/cycles/render/constant_fold.h
index 33f93b8c0ab..cc24d614206 100644
--- a/intern/cycles/render/constant_fold.h
+++ b/intern/cycles/render/constant_fold.h
@@ -22,6 +22,7 @@
 
 CCL_NAMESPACE_BEGIN
 
+class Scene;
 class ShaderGraph;
 class ShaderInput;
 class ShaderNode;
@@ -33,7 +34,9 @@ public:
 	ShaderNode *const node;
 	ShaderOutput *const output;
 
-	ConstantFolder(ShaderGraph *graph, ShaderNode *node, ShaderOutput *output);
+	Scene *scene;
+
+	ConstantFolder(ShaderGraph *graph, ShaderNode *node, ShaderOutput *output, Scene *scene);
 
 	bool all_inputs_constant() const;
 
diff --git a/intern/cycles/render/graph.cpp b/intern/cycles/render/graph.cpp
index e1c09373004..8b179f742c4 100644
--- a/intern/cycles/render/graph.cpp
+++ b/intern/cycles/render/graph.cpp
@@ -496,7 +496,7 @@ void ShaderGraph::remove_proxy_nodes()
  * Try to constant fold some nodes, and pipe result directly to
  * the input socket of connected nodes.
  */
-void ShaderGraph::constant_fold()
+void ShaderGraph::constant_fold(Scene *scene)
 {
 	ShaderNodeSet done, scheduled;
 	queue<ShaderNode*> traverse_queue;
@@ -536,7 +536,7 @@ void ShaderGraph::constant_fold()
 				}
 			}
 			/* Optimize current node. */
-			ConstantFolder folder(this, node, output);
+			ConstantFolder folder(this, node, output, scene);
 			node->constant_fold(folder);
 		}
 	}
@@ -734,7 +734,7 @@ void ShaderGraph::clean(Scene *scene)
 	/* Graph simplification */
 
 	/* NOTE: Remove proxy nodes was already done. */
-	constant_fold();
+	constant_fold(scene);
 	simplify_settings(scene);
 	deduplicate_nodes();
 	verify_volume_output();
diff --git a/intern/cycles/render/graph.h b/intern/cycles/render/graph.h
index 2c134932b3c..5d986ae4827 100644
--- a/intern/cycles/render/graph.h
+++ b/intern/cycles/render/graph.h
@@ -285,7 +285,7 @@ protected:
 
 	/* Graph simplification routines. */
 	void clean(Scene *scene);
-	void constant_fold();
+	void constant_fold(Scene *scene);
 	void simplify_settings(Scene *scene);
 	void deduplicate_nodes();
 	void verify_volume_output();
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 3dad4d1a346..0f2581b2a2e 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include "render/film.h"
 #include "render/image.h"
 #include "render/integrator.h"
 #include "render/light.h"
@@ -1673,7 +1674,8 @@ RGBToBWNode::RGBToBWNode()
 void RGBToBWNode::constant_fold(const ConstantFolder& folder)
 {
 	if(folder.all_inputs_constant()) {
-		folder.make_constant(linear_rgb_to_gray(color));
+		float val = folder.scene->shader_manager->linear_rgb_to_gray(color);
+		folder.make_constant(val);
 	}
 }
 
@@ -1769,7 +1771,8 @@ void ConvertNode::constant_fold(const ConstantFolder& folder)
 			if(to == SocketType::FLOAT) {
 				if(from == SocketType::COLOR) {
 					/* color to float */
-					folder.make_constant(linear_rgb_to_gray(value_color));
+					float val = folder.scene->shader_manager->linear_rgb_to_gray(value_color);
+					folder.make_constant(val);
 				}
 				else {
 					/* vector/point/normal to float */
diff --git a/intern/cycles/render/shader.cpp b/intern/cycles/render/shader.cpp
index ec52c51e337..e34f272d9b6 100644
--- a/intern/cycles/render/shader.cpp
+++ b/intern/cycles/render/shader.cpp
@@ -31,6 +31,11 @@
 
 #include "util/util_foreach.h"
 
+#ifdef WITH_OCIO
+#  include <OpenColorIO/OpenColorIO.h>
+namespace OCIO = OCIO_NAMESPACE;
+#endif
+
 CCL_NAMESPACE_BEGIN
 
 thread_mutex ShaderManager::lookup_table_mutex;
@@ -338,6 +343,40 @@ ShaderManager::ShaderManager()
 {
 	need_update = true;
 	beckmann_table_offset = TABLE_OFFSET_INVALID;
+
+	xyz_to_r = make_float3( 3.2404542f, -1.5371385f, -0.4985314f);
+	xyz_to_g = make_float3(-0.9692660f,  1.8760108f,  0.0415560f);
+	xyz_to_b = make_float3( 0.0556434f, -0.2040259f,  1.0572252f);
+	rgb_to_y = make_float3( 0.2126729f,  0.7151522f,  0.0721750f);
+
+#ifdef WITH_OCIO
+	OCIO::ConstConfigRcPtr config = OCIO::GetCurrentConfig();
+	if(config) {
+		if(config->hasRole("XYZ") && config->hasRole("scene_linear")) {
+			OCIO::ConstProcessorRcPtr to_rgb_processor = config->getProcessor("XYZ", "scene_linear");
+			OCIO::ConstProcessorRcPtr to_xyz_processor = config->getProcessor("scene_linear", "XYZ");
+			if(to_rgb_processor && to_xyz_processor) {
+				float r[] = {1.0f, 0.0f, 0.0f};
+				float g[] = {0.0f, 1.0f, 0.0f};
+				float b[] = {0.0f, 0.0f, 1.0f};
+				to_xyz_processor->applyRGB(r);
+				to_xyz_processor->applyRGB(g);
+				to_xyz_processor->applyRGB(b);
+				rgb_to_y = make_float3(r[1], g[1], b[1]);
+
+				float x[] = {1.0f, 0.0f, 0.0f};
+				float y[] = {0.0f, 1.0f, 0.0f};
+				float z[] = {0.0f, 0.0f, 1.0f};
+				to_rgb_processor->applyRGB(x);
+				to_rgb_processor->applyRGB(y);
+				to_rgb_processor->applyRGB(z);
+				xyz_to_r = make_float3(x[0], y[0], z[0]);
+				xyz_to_g = make_float3(x[1], y[1], z[1]);
+				xyz_to_b = make_float3(x[2], y[2], z[2]);
+			}
+		}
+	}
+#endif
 }
 
 ShaderManager::~ShaderManager()
@@ -518,6 +557,14 @@ void ShaderManager::device_update_common(Device *device,
 	kintegrator->use_volumes = has_volumes;
 	/* TODO(sergey): De-duplicate with flags set in integrator.cpp. */
 	kintegrator->transparent_shadows = has_transparent_shadow;
+
+	/* film */
+	KernelFilm *kfilm = &dscene->data.film;
+	/* color space, needs to be here because e.g. displacement shaders could depend on it */
+	kfilm->xyz_to_r = xyz_to_r;
+	kfilm->xyz_to_g = xyz_to_g;
+	kfilm->xyz_to_b = xyz_to_b;
+	kfilm->rgb_to_y = rgb_to_y;
 }
 
 void ShaderManager::device_free_common(Device *, DeviceScene *dscene, Scene *scene)
@@ -643,5 +690,10 @@ void ShaderManager::free_memory()
 	beckmann_table.free_memory();
 }
 
+float ShaderManager::linear_rgb_to_gray(float3 c)
+{
+	return dot(c, rgb_to_y);
+}
+
 CCL_NAMESPACE_END
 
diff --git a/intern/cycles/render/shader.h b/intern/cycles/render/shader.h
index abd483caabc..0353da90013 100644
--- a/intern/cycles/render/shader.h
+++ b/intern/cycles/render/shader.h
@@ -195,6 +195,8 @@ public:
 
 	static void free_memory();
 
+	float linear_rgb_to_gray(float3 c);
+
 protected:
 	ShaderManager();
 
@@ -211,6 +213,11 @@ protected:
 	                                  DeviceRequestedFeatures *requested_features);
 
 	thread_spin_lock attribute_lock_;
+
+	float3 xyz_to_r;
+	float3 xyz_to_g;
+	float3 xyz_to_b;
+	float3 rgb_to_y;
 };
 
 CCL_NAMESPACE_END
diff --git a/intern/cycles/test/CMakeLists.txt b/intern/cycles/test/CMakeLists.txt
index f3e49dc0c4e..46c525eb3bb 100644
--- a/intern/cycles/test/CMakeLists.txt
+++ b/intern/cycles/test/CMakeLists.txt
@@ -42,6 +42,11 @@ if(WITH_CYCLES_OSL)
 		${LLVM_LIBRARIES}
 	)
 endif()
+if(WITH_OPENCOLORIO)
+	list(APPEND ALL_CYCLES_LIBRARIES
+		${OPENCOLORIO_LIBRARIES}
+	)
+endif()
 if(WITH_IMAGE_OPENJPEG)
 	if(WITH_SYSTEM_OPENJPEG)
 		list(APPEND ALL_CYCLES_LIBRARIES ${OPENJPEG_LIBRARIES})
diff --git a/intern/cycles/util/util_color.h b/intern/cycles/util/util_color.h
index c73beab98dc..62a9bf8e47d 100644
--- a/intern/cycles/util/util_color.h
+++ b/intern/cycles/util/util_color.h
@@ -47,7 +47,7 @@ ccl_device_inline float3 color_byte_to_float(uchar4 c)
 	return make_float3(c.x*(1.0f/255.0f), c.y*(1.0f/255.0f), c.z*(1.0f/255.0f));
 }
 
-ccl_device float color_srgb_to_scene_linear(float c)
+ccl_device float color_srgb_to_linear(float c)
 {
 	if(c < 0.04045f)
 		return (c < 0.0f)? 0.0f: c * (1.0f/12.92f);
@@ -55,7 +55,7 @@ ccl_device float color_srgb_to_scene_linear(float c)
 		return powf((c + 0.055f) * (1.0f / 1.055f), 2.4f);
 }
 
-ccl_device float color_scene_linear_to_srgb(float c)
+ccl_device float color_linear_to_srgb(float c)
 {
 	if(c < 0.0031308f)
 		return (c < 0.0f)? 0.0f: c * 12.92f;
@@ -150,13 +150,6 @@ ccl_device float3 xyY_to_xyz(float x, float y, float Y)
 	return make_float3(X, Y, Z);
 }
 
-ccl_device float3 xyz_to_rgb(float x, float y, float z)
-{
-	return make_float3(3.240479f * x + -1.537150f * y + -0.498535f * z,
-	                  -0.969256f * x +  1.875991f * y +  0.041556f * z,
-	                   0.055648f * x + -0.204043f * y +  1.057311f * z);
-}
-
 #ifdef __KERNEL_SSE2__
 /*
  * Calculate initial guess for arg^exp based on float representation
@@ -204,7 +197,7 @@ ccl_device_inline ssef fastpow24(const ssef &arg)
 	return x * (x * x);
 }
 
-ccl_device ssef color_srgb_to_scene_linear(const ssef &c)
+ccl_device ssef color_srgb_to_linear(const ssef &c)
 {
 	sseb cmp = c < ssef(0.04045f);
 	ssef lt = max(c * ssef(1.0f/12.92f), ssef(0.0f));
@@ -214,42 +207,37 @@ ccl_device ssef color_srgb_to_scene_linear(const ssef &c)
 }
 #endif  /* __KERNEL_SSE2__ */
 
-ccl_device float3 color_srgb_to_scene_linear_v3(float3 c)
+ccl_device float3 color_srgb_to_linear_v3(float3 c)
 {
-	return make_float3(color_srgb_to_scene_linear(c.x),
-	                   color_srgb_to_scene_linear(c.y),
-	                   color_srgb_to_scene_linear(c.z));
+	return make_float3(color_srgb_to_linear(c.x),
+	                   color_srgb_to_linear(c.y),
+	                   color_srgb_to_linear(c.z));
 }
 
-ccl_device float3 color_scene_linear_to_srgb_v3(float3 c)
+ccl_device float3 color_linear_to_srgb_v3(float3 c)
 {
-	return make_float3(color_scene_linear_to_srgb(c.x),
-	                   color_scene_linear_to_srgb(c.y),
-	                   color_scene_linear_to_srgb(c.z));
+	return make_float3(color_linear_to_srgb(c.x),
+	                   color_linear_to_srgb(c.y),
+	                   color_linear_to_srgb(c.z));
 }
 
-ccl_device float4 color_srgb_to_scene_linear_v4(float4 c)
+ccl_device float4 color_srgb_to_linear_v4(float4 c)
 {
 #ifdef __KERNEL_SSE2__
 	ssef r_ssef;
 	float4 &r = (float4 &)r_ssef;
 	r = c;
-	r_ssef = color_srgb_to_scene_linear(r_ssef);
+	r_ssef = color_srgb_to_linear(r_ssef);
 	r.w = c.w;
 	return r;
 #else
-	return make_float4(color_srgb_to_scene_linear(c.x),
-	                   color_srgb_to_scene_linear(c.y),
-	                   color_srgb_to_scene_linear(c.z),
+	return make_float4(color_srgb_to_linear(c.x),
+	                   color_srgb_to_linear(c.y),
+	                   color_srgb_to_linear(c.z),
 	                   c.w);
 #endif
 }
 
-ccl_device float linear_rgb_to_gray(float3 c)
-{
-	return c.x*0.2126f + c.y*0.7152f + c.z*0.0722f;
-}
-
 CCL_NAMESPACE_END
 
 #endif /* __UTIL_COLOR_H__ */
diff --git a/release/datafiles/colormanagement/config.ocio b/release/datafiles/colormanagement/config.ocio
index 71223ea828e..ce79dfeb540 100644
--- a/release/datafiles/colormanagement/config.ocio
+++ b/release/datafiles/colormanagement/config.ocio
@@ -40,6 +40,9 @@ roles:
   # Non-color data
   data: Non-Color
 
+  # CIE XYZ color space
+  XYZ: XYZ
+
 displays:
   sRGB:
     - !<View> {name: Default, colorspace: sRGB}
@@ -188,8 +191,7 @@ colorspaces:
     allocationvars: [-8.5, 5]
     from_reference: !<GroupTransform>
       children:
-        - !<FileTransform> {src: rec709_to_aces.spimtx, interpolation: linear}
-        - !<FileTransform> {src: aces_to_xyz.spimtx, interpolation: linear}
+        - !<FileTransform> {src: srgb_to_xyz.spimtx, interpolation: linear}
 
   - !<ColorSpace>
     name: rrt_xyz