Cycles: support for custom shader AOVs

Custom render passes are added in the Shader AOVs panel in the view layer
settings, with a name and data type. In shader nodes, an AOV Output node
is then used to output either a value or color to the pass.

Arbitrary names can be used for these passes, as long as they don't conflict
with built-in passes that are enabled. The AOV Output node can be used in both
material and world shader nodes.

Implemented by Lukas, with tweaks by Brecht.

Differential Revision: https://developer.blender.org/D4837

4 files changed, 54 insertions, 0 deletions

diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt
index f618f964b22..fb2cb11d269 100644
--- a/source/blender/nodes/CMakeLists.txt
+++ b/source/blender/nodes/CMakeLists.txt
@@ -177,6 +177,7 @@ set(SRC
   shader/nodes/node_shader_output_linestyle.c
   shader/nodes/node_shader_output_material.c
   shader/nodes/node_shader_output_world.c
+  shader/nodes/node_shader_output_aov.c
   shader/nodes/node_shader_particle_info.c
   shader/nodes/node_shader_rgb.c
   shader/nodes/node_shader_script.c
diff --git a/source/blender/nodes/NOD_shader.h b/source/blender/nodes/NOD_shader.h
index a004090d03d..69d779c9b7f 100644
--- a/source/blender/nodes/NOD_shader.h
+++ b/source/blender/nodes/NOD_shader.h
@@ -120,6 +120,7 @@ void register_node_type_sh_output_material(void);
 void register_node_type_sh_output_eevee_material(void);
 void register_node_type_sh_output_world(void);
 void register_node_type_sh_output_linestyle(void);
+void register_node_type_sh_output_aov(void);
 
 void register_node_type_sh_tex_image(void);
 void register_node_type_sh_tex_environment(void);
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index a8163391c13..2b141e1a639 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -130,6 +130,7 @@ DefNode(ShaderNode,     SH_NODE_DISPLACEMENT,       def_sh_displacement,    "DIS
 DefNode(ShaderNode,     SH_NODE_VECTOR_DISPLACEMENT,def_sh_vector_displacement,"VECTOR_DISPLACEMENT",VectorDisplacement,"Vector Displacement",""  )
 DefNode(ShaderNode,     SH_NODE_TEX_IES,            def_sh_tex_ies,         "TEX_IES",            TexIES,           "IES Texture",       ""       )
 DefNode(ShaderNode,     SH_NODE_TEX_WHITE_NOISE,    def_sh_tex_white_noise, "TEX_WHITE_NOISE",    TexWhiteNoise,    "White Noise",       ""       )
+DefNode(ShaderNode,     SH_NODE_OUTPUT_AOV,         def_sh_output_aov,      "OUTPUT_AOV",         OutputAOV,        "AOV Output",        ""       )
 
 DefNode(CompositorNode, CMP_NODE_VIEWER,         def_cmp_viewer,         "VIEWER",         Viewer,           "Viewer",            ""              )
 DefNode(CompositorNode, CMP_NODE_RGB,            0,                      "RGB",            RGB,              "RGB",               ""              )
diff --git a/source/blender/nodes/shader/nodes/node_shader_output_aov.c b/source/blender/nodes/shader/nodes/node_shader_output_aov.c
new file mode 100644
index 00000000000..a3ecb06157e
--- /dev/null
+++ b/source/blender/nodes/shader/nodes/node_shader_output_aov.c
@@ -0,0 +1,51 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2005 Blender Foundation.
+ * All rights reserved.
+ */
+
+#include "../node_shader_util.h"
+
+/* **************** OUTPUT ******************** */
+
+static bNodeSocketTemplate sh_node_output_aov_in[] = {
+    {SOCK_RGBA, 1, N_("Color"), 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f},
+    {SOCK_FLOAT, 1, N_("Value"), 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f},
+    {-1, 0, ""},
+};
+
+static void node_shader_init_output_aov(bNodeTree *UNUSED(ntree), bNode *node)
+{
+  NodeShaderOutputAOV *aov = MEM_callocN(sizeof(NodeShaderOutputAOV), "NodeShaderOutputAOV");
+  node->storage = aov;
+}
+
+/* node type definition */
+void register_node_type_sh_output_aov(void)
+{
+  static bNodeType ntype;
+
+  sh_node_type_base(&ntype, SH_NODE_OUTPUT_AOV, "AOV Output", NODE_CLASS_OUTPUT, 0);
+  node_type_socket_templates(&ntype, sh_node_output_aov_in, NULL);
+  node_type_init(&ntype, node_shader_init_output_aov);
+  node_type_storage(
+      &ntype, "NodeShaderOutputAOV", node_free_standard_storage, node_copy_standard_storage);
+
+  /* Do not allow muting output node. */
+  node_type_internal_links(&ntype, NULL);
+
+  nodeRegisterType(&ntype);
+}