Shading: Add Volume Info node.

The Volume Info node provides the Color, Desnity, Flame, and Temperature
of smoke domains.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D5551

7 files changed, 90 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 6852f451b9d..e3d0588b607 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -979,6 +979,7 @@ void BKE_nodetree_remove_layer_n(struct bNodeTree *ntree,
 #define SH_NODE_MAP_RANGE 702
 #define SH_NODE_CLAMP 703
 #define SH_NODE_TEX_WHITE_NOISE 704
+#define SH_NODE_VOLUME_INFO 705
 
 /* 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 11a52bf53a9..206c59c110a 100644
--- a/source/blender/blenkernel/intern/node.c
+++ b/source/blender/blenkernel/intern/node.c
@@ -3960,6 +3960,7 @@ static void registerTextureNodes(void)
   register_node_type_sh_tangent();
   register_node_type_sh_normal_map();
   register_node_type_sh_hair_info();
+  register_node_type_sh_volume_info();
 
   register_node_type_tex_checker();
   register_node_type_tex_texture();
diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index df8f9d9457c..5ec24ec7086 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -2322,6 +2322,35 @@ void node_attribute_volume_temperature(
   outcol = vec4(outf, outf, outf, 1.0);
 }
 
+void node_volume_info(sampler3D densitySampler,
+                      sampler3D flameSampler,
+                      vec2 temperature,
+                      out vec4 outColor,
+                      out float outDensity,
+                      out float outFlame,
+                      out float outTemprature)
+{
+#if defined(MESH_SHADER) && defined(VOLUMETRICS)
+  vec3 p = volumeObjectLocalCoord;
+#else
+  vec3 p = vec3(0.0);
+#endif
+
+  vec4 density = texture(densitySampler, p);
+  outDensity = density.a;
+
+  /* Density is premultiplied for interpolation, divide it out here. */
+  if (density.a > 1e-8) {
+    density.rgb /= density.a;
+  }
+  outColor = vec4(density.rgb * volumeColor, 1.0);
+
+  float flame = texture(flameSampler, p).r;
+  outFlame = flame;
+
+  outTemprature = (flame > 0.01) ? temperature.x + flame * (temperature.y - temperature.x) : 0.0;
+}
+
 void node_attribute(vec3 attr, out vec4 outcol, out vec3 outvec, out float outf)
 {
   outcol = vec4(attr, 1.0);
diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt
index 0e8248d2d34..5cf5e1ac6d3 100644
--- a/source/blender/nodes/CMakeLists.txt
+++ b/source/blender/nodes/CMakeLists.txt
@@ -209,6 +209,7 @@ set(SRC
   shader/nodes/node_shader_vectTransform.c
   shader/nodes/node_shader_vector_displacement.c
   shader/nodes/node_shader_volume_absorption.c
+  shader/nodes/node_shader_volume_info.c
   shader/nodes/node_shader_volume_principled.c
   shader/nodes/node_shader_volume_scatter.c
   shader/nodes/node_shader_wavelength.c
diff --git a/source/blender/nodes/NOD_shader.h b/source/blender/nodes/NOD_shader.h
index 71ed11a8cea..30673e7cd31 100644
--- a/source/blender/nodes/NOD_shader.h
+++ b/source/blender/nodes/NOD_shader.h
@@ -81,6 +81,7 @@ void register_node_type_sh_layer_weight(void);
 void register_node_type_sh_tex_coord(void);
 void register_node_type_sh_particle_info(void);
 void register_node_type_sh_hair_info(void);
+void register_node_type_sh_volume_info(void);
 void register_node_type_sh_script(void);
 void register_node_type_sh_normal_map(void);
 void register_node_type_sh_tangent(void);
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index 877a2981a90..d14511504f0 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -96,6 +96,7 @@ DefNode(ShaderNode,     SH_NODE_LIGHT_FALLOFF,      0,                      "LIG
 DefNode(ShaderNode,     SH_NODE_OBJECT_INFO,        0,                      "OBJECT_INFO",        ObjectInfo,       "Object Info",       ""       )
 DefNode(ShaderNode,     SH_NODE_PARTICLE_INFO,      0,                      "PARTICLE_INFO",      ParticleInfo,     "Particle Info",     ""       )
 DefNode(ShaderNode,     SH_NODE_HAIR_INFO,          0,                      "HAIR_INFO",          HairInfo,         "Hair Info",         ""       )
+DefNode(ShaderNode,     SH_NODE_VOLUME_INFO,        0,                      "VOLUME_INFO",        VolumeInfo,       "Volume Info",       ""       )
 DefNode(ShaderNode,     SH_NODE_WIREFRAME,          def_sh_tex_wireframe,   "WIREFRAME",          Wireframe,        "Wireframe",         ""       )
 DefNode(ShaderNode,     SH_NODE_WAVELENGTH,         0,                      "WAVELENGTH",         Wavelength,       "Wavelength",        ""       )
 DefNode(ShaderNode,     SH_NODE_BLACKBODY,          0,                      "BLACKBODY",          Blackbody,        "Blackbody",         ""       )
diff --git a/source/blender/nodes/shader/nodes/node_shader_volume_info.c b/source/blender/nodes/shader/nodes/node_shader_volume_info.c
new file mode 100644
index 00000000000..98c44dd590b
--- /dev/null
+++ b/source/blender/nodes/shader/nodes/node_shader_volume_info.c
@@ -0,0 +1,56 @@
+/*
+ * 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"
+
+static bNodeSocketTemplate sh_node_volume_info_out[] = {
+    {SOCK_RGBA, 0, N_("Color")},
+    {SOCK_FLOAT, 0, N_("Density")},
+    {SOCK_FLOAT, 0, N_("Flame")},
+    {SOCK_FLOAT, 0, N_("Temperature")},
+    {-1, 0, ""},
+};
+
+static int node_shader_gpu_volume_info(GPUMaterial *mat,
+                                       bNode *node,
+                                       bNodeExecData *UNUSED(execdata),
+                                       GPUNodeStack *in,
+                                       GPUNodeStack *out)
+{
+
+  return GPU_stack_link(mat,
+                        node,
+                        "node_volume_info",
+                        in,
+                        out,
+                        GPU_builtin(GPU_VOLUME_DENSITY),
+                        GPU_builtin(GPU_VOLUME_FLAME),
+                        GPU_builtin(GPU_VOLUME_TEMPERATURE));
+}
+
+void register_node_type_sh_volume_info(void)
+{
+  static bNodeType ntype;
+
+  sh_node_type_base(&ntype, SH_NODE_VOLUME_INFO, "Volume Info", NODE_CLASS_INPUT, 0);
+  node_type_socket_templates(&ntype, NULL, sh_node_volume_info_out);
+  node_type_gpu(&ntype, node_shader_gpu_volume_info);
+
+  nodeRegisterType(&ntype);
+}