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

10 files changed, 82 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 9501d3f8ec9..11f151af44d 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -990,6 +990,7 @@ void BKE_nodetree_remove_layer_n(struct bNodeTree *ntree,
 #define SH_NODE_TEX_WHITE_NOISE 704
 #define SH_NODE_VOLUME_INFO 705
 #define SH_NODE_VERTEX_COLOR 706
+#define SH_NODE_OUTPUT_AOV 707
 
 /* custom defines options for Material node */
 #define SH_NODE_MAT_DIFF 1
diff --git a/source/blender/blenkernel/intern/node.c b/source/blender/blenkernel/intern/node.c
index 578d81b157c..be28ca26459 100644
--- a/source/blender/blenkernel/intern/node.c
+++ b/source/blender/blenkernel/intern/node.c
@@ -4007,6 +4007,7 @@ static void registerShaderNodes(void)
   register_node_type_sh_output_material();
   register_node_type_sh_output_world();
   register_node_type_sh_output_linestyle();
+  register_node_type_sh_output_aov();
 
   register_node_type_sh_tex_image();
   register_node_type_sh_tex_environment();
diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index a02eeaa1502..35c9082b54c 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -1154,6 +1154,11 @@ static void node_shader_buts_white_noise(uiLayout *layout, bContext *UNUSED(C),
   uiItemR(layout, ptr, "noise_dimensions", 0, "", ICON_NONE);
 }
 
+static void node_shader_buts_output_aov(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+  uiItemR(layout, ptr, "name", 0, NULL, ICON_NONE);
+}
+
 /* only once called */
 static void node_shader_set_butfunc(bNodeType *ntype)
 {
@@ -1310,6 +1315,9 @@ static void node_shader_set_butfunc(bNodeType *ntype)
     case SH_NODE_TEX_WHITE_NOISE:
       ntype->draw_buttons = node_shader_buts_white_noise;
       break;
+    case SH_NODE_OUTPUT_AOV:
+      ntype->draw_buttons = node_shader_buts_output_aov;
+      break;
   }
 }
 
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index e3ea3a5b3f8..d94a05ccb81 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -1010,6 +1010,10 @@ typedef struct NodeShaderTexIES {
   char filepath[1024];
 } NodeShaderTexIES;
 
+typedef struct NodeShaderOutputAOV {
+  char name[64];
+} NodeShaderOutputAOV;
+
 typedef struct NodeSunBeams {
   float source[2];
 
diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 7fe88ec94b7..94f2ec25ded 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -574,6 +574,7 @@ extern StructRNA RNA_ShaderNodeMath;
 extern StructRNA RNA_ShaderNodeMixRGB;
 extern StructRNA RNA_ShaderNodeNormal;
 extern StructRNA RNA_ShaderNodeOutput;
+extern StructRNA RNA_ShaderNodeOutputAOV;
 extern StructRNA RNA_ShaderNodeRGB;
 extern StructRNA RNA_ShaderNodeRGBCurve;
 extern StructRNA RNA_ShaderNodeRGBToBW;
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 0a47830b1e3..17e34cd60ad 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -5187,6 +5187,19 @@ static void def_sh_tex_ies(StructRNA *srna)
   RNA_def_struct_sdna_from(srna, "bNode", NULL);
 }
 
+static void def_sh_output_aov(StructRNA *srna)
+{
+  PropertyRNA *prop;
+
+  RNA_def_struct_sdna_from(srna, "NodeShaderOutputAOV", "storage");
+
+  prop = RNA_def_property(srna, "name", PROP_STRING, PROP_NONE);
+  RNA_def_property_ui_text(prop, "Name", "Name of the AOV that this output writes to");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+
+  RNA_def_struct_sdna_from(srna, "bNode", NULL);
+}
+
 static void def_sh_script(StructRNA *srna)
 {
   PropertyRNA *prop;
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);
+}