Objects: Eevee and workbench rendering of new Volume, Hair, PointCloud

Only the volume drawing part is really finished and exposed to the user. Hair
plugs into the existing hair rendering code and is fairly straightforward. The
pointcloud drawing is a hack using overlays rather than Eevee and workbench.

The most tricky part for volume rendering is the case where each volume grid
has a different transform, which requires an additional matrix in the shader
and non-trivial logic in Eevee volume drawing. In the common case were all the
transforms match we don't use the additional per-grid matrix in the shader.

Ref T73201, T68981

Differential Revision: https://developer.blender.org/D6955

5 files changed, 40 insertions, 9 deletions

diff --git a/source/blender/gpu/GPU_material.h b/source/blender/gpu/GPU_material.h
index da00306bf9f..337c0b03308 100644
--- a/source/blender/gpu/GPU_material.h
+++ b/source/blender/gpu/GPU_material.h
@@ -233,7 +233,8 @@ typedef struct GPUMaterialTexture {
 typedef struct GPUMaterialVolumeGrid {
   struct GPUMaterialVolumeGrid *next, *prev;
   char *name;
-  char sampler_name[32]; /* Name of sampler in GLSL. */
+  char sampler_name[32];   /* Name of sampler in GLSL. */
+  char transform_name[32]; /* Name of 4x4 matrix in GLSL. */
   int users;
 } GPUMaterialVolumeGrid;
 
diff --git a/source/blender/gpu/intern/gpu_codegen.c b/source/blender/gpu/intern/gpu_codegen.c
index bcaa95c2f59..066b8d633d2 100644
--- a/source/blender/gpu/intern/gpu_codegen.c
+++ b/source/blender/gpu/intern/gpu_codegen.c
@@ -335,6 +335,7 @@ static int codegen_process_uniforms_functions(GPUMaterial *material,
   /* Volume Grids */
   for (GPUMaterialVolumeGrid *grid = graph->volume_grids.first; grid; grid = grid->next) {
     BLI_dynstr_appendf(ds, "uniform sampler3D %s;\n", grid->sampler_name);
+    BLI_dynstr_appendf(ds, "uniform mat4 %s = mat4(0.0);\n", grid->transform_name);
   }
 
   /* Print other uniforms */
@@ -432,6 +433,9 @@ static void codegen_call_functions(DynStr *ds, GPUNodeGraph *graph, GPUOutput *f
       else if (input->source == GPU_SOURCE_VOLUME_GRID) {
         BLI_dynstr_append(ds, input->volume_grid->sampler_name);
       }
+      else if (input->source == GPU_SOURCE_VOLUME_GRID_TRANSFORM) {
+        BLI_dynstr_append(ds, input->volume_grid->transform_name);
+      }
       else if (input->source == GPU_SOURCE_OUTPUT) {
         codegen_convert_datatype(
             ds, input->link->output->type, input->type, "tmp", input->link->output->id);
diff --git a/source/blender/gpu/intern/gpu_node_graph.c b/source/blender/gpu/intern/gpu_node_graph.c
index 0d5cc46c0b9..0eb62bf5b2f 100644
--- a/source/blender/gpu/intern/gpu_node_graph.c
+++ b/source/blender/gpu/intern/gpu_node_graph.c
@@ -123,6 +123,10 @@ static void gpu_node_input_link(GPUNode *node, GPUNodeLink *link, const eGPUType
       input->source = GPU_SOURCE_VOLUME_GRID;
       input->volume_grid = link->volume_grid;
       break;
+    case GPU_NODE_LINK_VOLUME_GRID_TRANSFORM:
+      input->source = GPU_SOURCE_VOLUME_GRID_TRANSFORM;
+      input->volume_grid = link->volume_grid;
+      break;
     case GPU_NODE_LINK_ATTR:
       input->source = GPU_SOURCE_ATTR;
       input->attr = link->attr;
@@ -342,6 +346,7 @@ static GPUMaterialVolumeGrid *gpu_node_graph_add_volume_grid(GPUNodeGraph *graph
     grid = MEM_callocN(sizeof(*grid), __func__);
     grid->name = BLI_strdup(name);
     BLI_snprintf(grid->sampler_name, sizeof(grid->sampler_name), "vsamp%d", num_grids);
+    BLI_snprintf(grid->transform_name, sizeof(grid->transform_name), "vtfm%d", num_grids);
     BLI_addtail(&graph->volume_grids, grid);
   }
 
@@ -432,16 +437,20 @@ GPUNodeLink *GPU_volume_grid(GPUMaterial *mat, const char *name)
   link->link_type = GPU_NODE_LINK_VOLUME_GRID;
   link->volume_grid = gpu_node_graph_add_volume_grid(graph, name);
 
+  GPUNodeLink *transform_link = gpu_node_link_create();
+  transform_link->link_type = GPU_NODE_LINK_VOLUME_GRID_TRANSFORM;
+  transform_link->volume_grid = link->volume_grid;
+
   /* Two special cases, where we adjust the output values of smoke grids to
    * bring the into standard range without having to modify the grid values. */
   if (strcmp(name, "color") == 0) {
-    GPU_link(mat, "node_attribute_volume_color", link, &link);
+    GPU_link(mat, "node_attribute_volume_color", link, transform_link, &link);
   }
   else if (strcmp(name, "temperature") == 0) {
-    GPU_link(mat, "node_attribute_volume_temperature", link, &link);
+    GPU_link(mat, "node_attribute_volume_temperature", link, transform_link, &link);
   }
   else {
-    GPU_link(mat, "node_attribute_volume", link, &link);
+    GPU_link(mat, "node_attribute_volume", link, transform_link, &link);
   }
 
   return link;
@@ -590,7 +599,7 @@ static void gpu_inputs_free(ListBase *inputs)
     else if (ELEM(input->source, GPU_SOURCE_TEX, GPU_SOURCE_TEX_TILED_MAPPING)) {
       input->texture->users--;
     }
-    else if (ELEM(input->source, GPU_SOURCE_VOLUME_GRID)) {
+    else if (ELEM(input->source, GPU_SOURCE_VOLUME_GRID, GPU_SOURCE_VOLUME_GRID_TRANSFORM)) {
       input->volume_grid->users--;
     }
 
diff --git a/source/blender/gpu/intern/gpu_node_graph.h b/source/blender/gpu/intern/gpu_node_graph.h
index ceaeea2bfa8..8506c6a87e2 100644
--- a/source/blender/gpu/intern/gpu_node_graph.h
+++ b/source/blender/gpu/intern/gpu_node_graph.h
@@ -62,6 +62,7 @@ typedef enum {
   GPU_NODE_LINK_IMAGE_TILED,
   GPU_NODE_LINK_IMAGE_TILED_MAPPING,
   GPU_NODE_LINK_VOLUME_GRID,
+  GPU_NODE_LINK_VOLUME_GRID_TRANSFORM,
   GPU_NODE_LINK_OUTPUT,
   GPU_NODE_LINK_UNIFORM,
 } GPUNodeLinkType;
@@ -131,7 +132,7 @@ typedef struct GPUInput {
     struct GPUMaterialTexture *texture;
     /* GPU_SOURCE_ATTR */
     struct GPUMaterialAttribute *attr;
-    /* GPU_SOURCE_VOLUME_GRID */
+    /* GPU_SOURCE_VOLUME_GRID | GPU_SOURCE_VOLUME_GRID_TRANSFORM */
     struct GPUMaterialVolumeGrid *volume_grid;
   };
 } GPUInput;
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl
index a80cd3cb329..e6d7b9d3721 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl
@@ -4,18 +4,24 @@ uniform vec3 volumeColor = vec3(1.0);
 uniform vec2 volumeTemperature = vec2(0.0);
 
 /* Generic volume attribute. */
-void node_attribute_volume(sampler3D tex, out vec3 outvec)
+void node_attribute_volume(sampler3D tex, mat4 transform, out vec3 outvec)
 {
 #if defined(MESH_SHADER) && defined(VOLUMETRICS)
   vec3 cos = volumeObjectLocalCoord;
 #else
   vec3 cos = vec3(0.0);
 #endif
+
+  /* Optional per-grid transform. */
+  if (transform[3][3] != 0.0) {
+    cos = (transform * vec4(cos, 1.0)).xyz;
+  }
+
   outvec = texture(tex, cos).rgb;
 }
 
 /* Special color attribute for smoke. */
-void node_attribute_volume_color(sampler3D tex, out vec3 outvec)
+void node_attribute_volume_color(sampler3D tex, mat4 transform, out vec3 outvec)
 {
 #if defined(MESH_SHADER) && defined(VOLUMETRICS)
   vec3 cos = volumeObjectLocalCoord;
@@ -23,6 +29,11 @@ void node_attribute_volume_color(sampler3D tex, out vec3 outvec)
   vec3 cos = vec3(0.0);
 #endif
 
+  /* Optional per-grid transform. */
+  if (transform[3][3] != 0.0) {
+    cos = (transform * vec4(cos, 1.0)).xyz;
+  }
+
   /* Density is premultiplied for interpolation, divide it out here. */
   vec4 value = texture(tex, cos).rgba;
   if (value.a > 1e-8) {
@@ -33,7 +44,7 @@ void node_attribute_volume_color(sampler3D tex, out vec3 outvec)
 }
 
 /* Special temperature attribute for smoke. */
-void node_attribute_volume_temperature(sampler3D tex, out float outf)
+void node_attribute_volume_temperature(sampler3D tex, mat4 transform, out float outf)
 {
 #if defined(MESH_SHADER) && defined(VOLUMETRICS)
   vec3 cos = volumeObjectLocalCoord;
@@ -41,6 +52,11 @@ void node_attribute_volume_temperature(sampler3D tex, out float outf)
   vec3 cos = vec3(0.0);
 #endif
 
+  /* Optional per-grid transform. */
+  if (transform[3][3] != 0.0) {
+    cos = (transform * vec4(cos, 1.0)).xyz;
+  }
+
   float value = texture(tex, cos).r;
   if (volumeTemperature.x < volumeTemperature.y) {
     outf = (value > 0.01) ?