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

6 files changed, 184 insertions, 37 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
index e957f8bbe9c..0c2b7850f94 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
@@ -11,6 +11,7 @@ uniform sampler3D shadowTexture;
 uniform sampler3D flameTexture;
 uniform sampler1D flameColorTexture;
 uniform sampler1D transferTexture;
+uniform mat4 volumeObjectToTexture;
 
 uniform int samplesLen = 256;
 uniform float noiseOfs = 0.0;
@@ -110,20 +111,24 @@ void volume_properties(vec3 ls_pos, out vec3 scattering, out float extinction)
   scattering = tval.rgb * 1500.0;
   extinction = max(1e-4, tval.a * 50.0);
 #else
+#  ifdef VOLUME_SMOKE
   float flame = sample_volume_texture(flameTexture, co).r;
   vec4 emission = texture(flameColorTexture, flame);
+#  endif
+  vec3 density = sample_volume_texture(densityTexture, co).rgb;
   float shadows = sample_volume_texture(shadowTexture, co).r;
-  vec4 density = sample_volume_texture(densityTexture, co); /* rgb: color, a: density */
 
-  scattering = density.rgb * densityScale;
+  scattering = density * densityScale;
   extinction = max(1e-4, dot(scattering, vec3(0.33333)));
   scattering *= activeColor;
 
   /* Scale shadows in log space and clamp them to avoid completely black shadows. */
   scattering *= exp(clamp(log(shadows) * densityScale * 0.1, -2.5, 0.0)) * M_PI;
 
+#  ifdef VOLUME_SMOKE
   /* 800 is arbitrary and here to mimic old viewport. TODO make it a parameter */
   scattering += pow(emission.rgb, vec3(2.2)) * emission.a * 800.0;
+#  endif
 #endif
 }
 
@@ -201,9 +206,16 @@ void main()
   vec3 ls_ray_ori = point_view_to_object(vs_ray_ori);
   vec3 ls_ray_end = point_view_to_object(vs_ray_end);
 
+#  ifdef VOLUME_SMOKE
   ls_ray_dir = (OrcoTexCoFactors[0].xyz + ls_ray_dir * OrcoTexCoFactors[1].xyz) * 2.0 - 1.0;
   ls_ray_ori = (OrcoTexCoFactors[0].xyz + ls_ray_ori * OrcoTexCoFactors[1].xyz) * 2.0 - 1.0;
   ls_ray_end = (OrcoTexCoFactors[0].xyz + ls_ray_end * OrcoTexCoFactors[1].xyz) * 2.0 - 1.0;
+#  else
+  ls_ray_dir = (volumeObjectToTexture * vec4(ls_ray_dir, 1.0)).xyz * 2.0f - 1.0;
+  ls_ray_ori = (volumeObjectToTexture * vec4(ls_ray_ori, 1.0)).xyz * 2.0f - 1.0;
+  ls_ray_end = (volumeObjectToTexture * vec4(ls_ray_end, 1.0)).xyz * 2.0f - 1.0;
+#  endif
+
   ls_ray_dir -= ls_ray_ori;
 
   /* TODO: Align rays to volume center so that it mimics old behaviour of slicing the volume. */
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_volume_vert.glsl b/source/blender/draw/engines/workbench/shaders/workbench_volume_vert.glsl
index 1a32a202290..7327a92e04f 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_volume_vert.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_volume_vert.glsl
@@ -5,6 +5,8 @@
 uniform float slicePosition;
 uniform int sliceAxis; /* -1 is no slice, 0 is X, 1 is Y, 2 is Z. */
 
+uniform mat4 volumeTextureToObject;
+
 in vec3 pos;
 
 RESOURCE_ID_VARYING
@@ -31,7 +33,12 @@ void main()
 #else
   vec3 final_pos = pos;
 #endif
+
+#ifdef VOLUME_SMOKE
   final_pos = ((final_pos * 0.5 + 0.5) - OrcoTexCoFactors[0].xyz) / OrcoTexCoFactors[1].xyz;
+#else
+  final_pos = (volumeTextureToObject * vec4(final_pos * 0.5 + 0.5, 1.0)).xyz;
+#endif
   gl_Position = point_object_to_ndc(final_pos);
 
   PASS_RESOURCE_ID
diff --git a/source/blender/draw/engines/workbench/workbench_engine.c b/source/blender/draw/engines/workbench/workbench_engine.c
index 742489c7311..e9525af5682 100644
--- a/source/blender/draw/engines/workbench/workbench_engine.c
+++ b/source/blender/draw/engines/workbench/workbench_engine.c
@@ -33,8 +33,9 @@
 #include "BKE_paint.h"
 #include "BKE_particle.h"
 
-#include "DNA_image_types.h"
 #include "DNA_fluid_types.h"
+#include "DNA_hair_types.h"
+#include "DNA_image_types.h"
 #include "DNA_mesh_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_node_types.h"
@@ -192,12 +193,12 @@ static void workbench_cache_common_populate(WORKBENCH_PrivateData *wpd,
 
 static void workbench_cache_hair_populate(WORKBENCH_PrivateData *wpd,
                                           Object *ob,
+                                          ParticleSystem *psys,
                                           ModifierData *md,
                                           eV3DShadingColorType color_type,
-                                          bool use_texpaint_mode)
+                                          bool use_texpaint_mode,
+                                          const int matnr)
 {
-  ParticleSystem *psys = ((ParticleSystemModifierData *)md)->psys;
-  ParticleSettings *part = psys->part;
   const DRWContextState *draw_ctx = DRW_context_state_get();
   const Scene *scene = draw_ctx->scene;
 
@@ -206,8 +207,8 @@ static void workbench_cache_hair_populate(WORKBENCH_PrivateData *wpd,
   int interp = (imapaint && imapaint->interp == IMAGEPAINT_INTERP_LINEAR) ? SHD_INTERP_LINEAR :
                                                                             SHD_INTERP_CLOSEST;
   DRWShadingGroup *grp = (use_texpaint_mode) ?
-                             workbench_image_hair_setup(wpd, ob, part->omat, ima, NULL, interp) :
-                             workbench_material_hair_setup(wpd, ob, part->omat, color_type);
+                             workbench_image_hair_setup(wpd, ob, matnr, ima, NULL, interp) :
+                             workbench_material_hair_setup(wpd, ob, matnr, color_type);
 
   DRW_shgroup_hair_create_sub(ob, psys, md, grp);
 }
@@ -244,14 +245,20 @@ static eV3DShadingColorType workbench_color_type_get(WORKBENCH_PrivateData *wpd,
     color_type = V3D_SHADING_OBJECT_COLOR;
   }
 
-  *r_sculpt_pbvh = is_sculpt_pbvh;
-  *r_texpaint_mode = false;
+  if (r_sculpt_pbvh) {
+    *r_sculpt_pbvh = is_sculpt_pbvh;
+  }
+  if (r_texpaint_mode) {
+    *r_texpaint_mode = false;
+  }
 
   if (!is_sculpt_pbvh && !is_render) {
     /* Force texture or vertex mode if object is in paint mode. */
     if (is_texpaint_mode && me && me->mloopuv) {
       color_type = V3D_SHADING_TEXTURE_COLOR;
-      *r_texpaint_mode = true;
+      if (r_texpaint_mode) {
+        *r_texpaint_mode = true;
+      }
     }
     else if (is_vertpaint_mode && me && me->mloopcol) {
       color_type = V3D_SHADING_VERTEX_COLOR;
@@ -286,8 +293,8 @@ void workbench_cache_populate(void *ved, Object *ob)
   }
 
   if (ob->type == OB_MESH && ob->modifiers.first != NULL) {
-    bool use_sculpt_pbvh, use_texpaint_mode;
-    int color_type = workbench_color_type_get(wpd, ob, &use_sculpt_pbvh, &use_texpaint_mode, NULL);
+    bool use_texpaint_mode;
+    int color_type = workbench_color_type_get(wpd, ob, NULL, &use_texpaint_mode, NULL);
 
     LISTBASE_FOREACH (ModifierData *, md, &ob->modifiers) {
       if (md->type != eModifierType_ParticleSystem) {
@@ -301,7 +308,8 @@ void workbench_cache_populate(void *ved, Object *ob)
       const int draw_as = (part->draw_as == PART_DRAW_REND) ? part->ren_as : part->draw_as;
 
       if (draw_as == PART_DRAW_PATH) {
-        workbench_cache_hair_populate(wpd, ob, md, color_type, use_texpaint_mode);
+        workbench_cache_hair_populate(
+            wpd, ob, psys, md, color_type, use_texpaint_mode, part->omat);
       }
     }
   }
@@ -311,7 +319,7 @@ void workbench_cache_populate(void *ved, Object *ob)
     if (md && modifier_isEnabled(wpd->scene, md, eModifierMode_Realtime)) {
       FluidModifierData *fmd = (FluidModifierData *)md;
       if (fmd->domain && fmd->domain->type == FLUID_DOMAIN_TYPE_GAS) {
-        workbench_volume_cache_populate(vedata, wpd->scene, ob, md);
+        workbench_volume_cache_populate(vedata, wpd->scene, ob, md, V3D_SHADING_SINGLE_COLOR);
         return; /* Do not draw solid in this case. */
       }
     }
@@ -325,7 +333,7 @@ void workbench_cache_populate(void *ved, Object *ob)
     return;
   }
 
-  if (ELEM(ob->type, OB_MESH, OB_CURVE, OB_SURF, OB_FONT, OB_MBALL)) {
+  if (ELEM(ob->type, OB_MESH, OB_CURVE, OB_SURF, OB_FONT, OB_MBALL, OB_POINTCLOUD)) {
     bool use_sculpt_pbvh, use_texpaint_mode, draw_shadow, has_transp_mat = false;
     eV3DShadingColorType color_type = workbench_color_type_get(
         wpd, ob, &use_sculpt_pbvh, &use_texpaint_mode, &draw_shadow);
@@ -344,6 +352,16 @@ void workbench_cache_populate(void *ved, Object *ob)
       workbench_shadow_cache_populate(vedata, ob, has_transp_mat);
     }
   }
+  else if (ob->type == OB_HAIR) {
+    int color_type = workbench_color_type_get(wpd, ob, NULL, NULL, NULL);
+    workbench_cache_hair_populate(wpd, ob, NULL, NULL, color_type, false, HAIR_MATERIAL_NR);
+  }
+  else if (ob->type == OB_VOLUME) {
+    if (wpd->shading.type != OB_WIRE) {
+      int color_type = workbench_color_type_get(wpd, ob, NULL, NULL, NULL);
+      workbench_volume_cache_populate(vedata, wpd->scene, ob, NULL, color_type);
+    }
+  }
 }
 
 void workbench_cache_finish(void *ved)
diff --git a/source/blender/draw/engines/workbench/workbench_private.h b/source/blender/draw/engines/workbench/workbench_private.h
index a68b66e0f85..49becf93f48 100644
--- a/source/blender/draw/engines/workbench/workbench_private.h
+++ b/source/blender/draw/engines/workbench/workbench_private.h
@@ -101,6 +101,7 @@ typedef struct WORKBENCH_TextureList {
   struct GPUTexture *smaa_area_tx;
   struct GPUTexture *dummy_image_tx;
   struct GPUTexture *dummy_volume_tx;
+  struct GPUTexture *dummy_shadow_tx;
   struct GPUTexture *dummy_coba_tx;
 } WORKBENCH_TextureList;
 
@@ -405,7 +406,7 @@ GPUShader *workbench_shader_outline_get(void);
 GPUShader *workbench_shader_antialiasing_accumulation_get(void);
 GPUShader *workbench_shader_antialiasing_get(int stage);
 
-GPUShader *workbench_shader_volume_get(bool slice, bool coba, bool cubic);
+GPUShader *workbench_shader_volume_get(bool slice, bool coba, bool cubic, bool smoke);
 
 void workbench_shader_depth_of_field_get(GPUShader **prepare_sh,
                                          GPUShader **downsample_sh,
@@ -479,7 +480,8 @@ void workbench_volume_cache_init(WORKBENCH_Data *vedata);
 void workbench_volume_cache_populate(WORKBENCH_Data *vedata,
                                      struct Scene *UNUSED(scene),
                                      struct Object *ob,
-                                     struct ModifierData *md);
+                                     struct ModifierData *md,
+                                     eV3DShadingColorType color_type);
 void workbench_volume_draw_pass(WORKBENCH_Data *vedata);
 void workbench_volume_draw_finish(WORKBENCH_Data *vedata);
 
diff --git a/source/blender/draw/engines/workbench/workbench_shader.c b/source/blender/draw/engines/workbench/workbench_shader.c
index 14a980fe628..2e796056029 100644
--- a/source/blender/draw/engines/workbench/workbench_shader.c
+++ b/source/blender/draw/engines/workbench/workbench_shader.c
@@ -106,7 +106,7 @@ static struct {
   struct GPUShader *aa_accum_sh;
   struct GPUShader *smaa_sh[3];
 
-  struct GPUShader *volume_sh[2][2][2];
+  struct GPUShader *volume_sh[2][2][2][2];
 
   struct DRWShaderLibrary *lib;
 } e_data = {{{{NULL}}}};
@@ -448,9 +448,9 @@ GPUShader *workbench_shader_antialiasing_get(int stage)
   return e_data.smaa_sh[stage];
 }
 
-GPUShader *workbench_shader_volume_get(bool slice, bool coba, bool cubic)
+GPUShader *workbench_shader_volume_get(bool slice, bool coba, bool cubic, bool smoke)
 {
-  GPUShader **shader = &e_data.volume_sh[slice][coba][cubic];
+  GPUShader **shader = &e_data.volume_sh[slice][coba][cubic][smoke];
 
   if (*shader == NULL) {
     DynStr *ds = BLI_dynstr_new();
@@ -464,6 +464,9 @@ GPUShader *workbench_shader_volume_get(bool slice, bool coba, bool cubic)
     if (cubic) {
       BLI_dynstr_append(ds, "#define USE_TRICUBIC\n");
     }
+    if (smoke) {
+      BLI_dynstr_append(ds, "#define VOLUME_SMOKE\n");
+    }
 
     char *defines = BLI_dynstr_get_cstring(ds);
     BLI_dynstr_free(ds);
@@ -513,7 +516,7 @@ void workbench_shader_free(void)
     DRW_SHADER_FREE_SAFE(sh_array[j]);
   }
   for (int j = 0; j < sizeof(e_data.volume_sh) / sizeof(void *); j++) {
-    struct GPUShader **sh_array = &e_data.volume_sh[0][0][0];
+    struct GPUShader **sh_array = &e_data.volume_sh[0][0][0][0];
     DRW_SHADER_FREE_SAFE(sh_array[j]);
   }
 
diff --git a/source/blender/draw/engines/workbench/workbench_volume.c b/source/blender/draw/engines/workbench/workbench_volume.c
index a3072b834bd..1eccc99d9e9 100644
--- a/source/blender/draw/engines/workbench/workbench_volume.c
+++ b/source/blender/draw/engines/workbench/workbench_volume.c
@@ -22,16 +22,20 @@
 
 #include "workbench_private.h"
 
-#include "BKE_object.h"
-#include "BKE_fluid.h"
+#include "DNA_fluid_types.h"
+#include "DNA_modifier_types.h"
+#include "DNA_object_force_types.h"
+#include "DNA_volume_types.h"
 
 #include "BLI_rand.h"
 #include "BLI_dynstr.h"
 #include "BLI_string_utils.h"
 
-#include "DNA_modifier_types.h"
-#include "DNA_object_force_types.h"
-#include "DNA_fluid_types.h"
+#include "BKE_fluid.h"
+#include "BKE_global.h"
+#include "BKE_object.h"
+#include "BKE_volume.h"
+#include "BKE_volume_render.h"
 
 #include "GPU_draw.h"
 
@@ -40,9 +44,11 @@ void workbench_volume_engine_init(WORKBENCH_Data *vedata)
   WORKBENCH_TextureList *txl = vedata->txl;
 
   if (txl->dummy_volume_tx == NULL) {
-    float pixel[4] = {0.0f, 0.0f, 0.0f, 0.0f};
-    txl->dummy_volume_tx = GPU_texture_create_3d(1, 1, 1, GPU_RGBA8, pixel, NULL);
-    txl->dummy_coba_tx = GPU_texture_create_1d(1, GPU_RGBA8, pixel, NULL);
+    float zero[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+    float one[4] = {1.0f, 1.0f, 1.0f, 1.0f};
+    txl->dummy_volume_tx = GPU_texture_create_3d(1, 1, 1, GPU_RGBA8, zero, NULL);
+    txl->dummy_shadow_tx = GPU_texture_create_3d(1, 1, 1, GPU_RGBA8, one, NULL);
+    txl->dummy_coba_tx = GPU_texture_create_1d(1, GPU_RGBA8, zero, NULL);
   }
 }
 
@@ -54,10 +60,9 @@ void workbench_volume_cache_init(WORKBENCH_Data *vedata)
   vedata->stl->wpd->volumes_do = false;
 }
 
-void workbench_volume_cache_populate(WORKBENCH_Data *vedata,
-                                     Scene *UNUSED(scene),
-                                     Object *ob,
-                                     ModifierData *md)
+static void workbench_volume_modifier_cache_populate(WORKBENCH_Data *vedata,
+                                                     Object *ob,
+                                                     ModifierData *md)
 {
   FluidModifierData *mmd = (FluidModifierData *)md;
   FluidDomainSettings *mds = mmd->domain;
@@ -90,8 +95,7 @@ void workbench_volume_cache_populate(WORKBENCH_Data *vedata,
   const bool use_slice = (mds->slice_method == FLUID_DOMAIN_SLICE_AXIS_ALIGNED &&
                           mds->axis_slice_method == AXIS_SLICE_SINGLE);
   const bool cubic_interp = (mds->interp_method == VOLUME_INTERP_CUBIC);
-
-  GPUShader *sh = workbench_shader_volume_get(use_slice, mds->use_coba, cubic_interp);
+  GPUShader *sh = workbench_shader_volume_get(use_slice, mds->use_coba, cubic_interp, true);
 
   if (use_slice) {
     float invviewmat[4][4];
@@ -162,6 +166,107 @@ void workbench_volume_cache_populate(WORKBENCH_Data *vedata,
   BLI_addtail(&wpd->smoke_domains, BLI_genericNodeN(mmd));
 }
 
+static void workbench_volume_material_color(WORKBENCH_PrivateData *wpd,
+                                            Object *ob,
+                                            eV3DShadingColorType color_type,
+                                            float color[3])
+{
+  Material *ma = BKE_object_material_get(ob, VOLUME_MATERIAL_NR);
+  WORKBENCH_UBO_Material ubo_data;
+  workbench_material_ubo_data(wpd, ob, ma, &ubo_data, color_type);
+  copy_v3_v3(color, ubo_data.base_color);
+}
+
+static void workbench_volume_object_cache_populate(WORKBENCH_Data *vedata,
+                                                   Object *ob,
+                                                   eV3DShadingColorType color_type)
+{
+  /* Create 3D textures. */
+  Volume *volume = ob->data;
+  BKE_volume_load(volume, G.main);
+  VolumeGrid *volume_grid = BKE_volume_grid_active_get(volume);
+  if (volume_grid == NULL) {
+    return;
+  }
+  DRWVolumeGrid *grid = DRW_volume_batch_cache_get_grid(volume, volume_grid);
+  if (grid == NULL) {
+    return;
+  }
+
+  WORKBENCH_PrivateData *wpd = vedata->stl->wpd;
+  WORKBENCH_TextureList *txl = vedata->txl;
+  DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
+
+  wpd->volumes_do = true;
+
+  /* Create shader. */
+  GPUShader *sh = workbench_shader_volume_get(false, false, false, false);
+
+  /* Compute color. */
+  float color[3];
+  workbench_volume_material_color(wpd, ob, color_type, color);
+
+  /* Combined texture to object, and object to world transform. */
+  float texture_to_world[4][4];
+  mul_m4_m4m4(texture_to_world, ob->obmat, grid->texture_to_object);
+
+  /* Compute world space dimensions for step size. */
+  float world_size[3];
+  mat4_to_size(world_size, texture_to_world);
+  abs_v3(world_size);
+
+  /* Compute step parameters. */
+  double noise_ofs;
+  BLI_halton_1d(3, 0.0, wpd->taa_sample, &noise_ofs);
+  float step_length, max_slice;
+  int resolution[3];
+  GPU_texture_get_mipmap_size(grid->texture, 0, resolution);
+  float slice_ct[3] = {resolution[0], resolution[1], resolution[2]};
+  mul_v3_fl(slice_ct, max_ff(0.001f, 5.0f));
+  max_slice = max_fff(slice_ct[0], slice_ct[1], slice_ct[2]);
+  invert_v3(slice_ct);
+  mul_v3_v3(slice_ct, world_size);
+  step_length = len_v3(slice_ct);
+
+  /* Compute density scale. */
+  const float density_scale = volume->display.density;
+
+  /* Set uniforms. */
+  DRWShadingGroup *grp = DRW_shgroup_create(sh, vedata->psl->volume_ps);
+  DRW_shgroup_uniform_block(grp, "world_block", wpd->world_ubo);
+  DRW_shgroup_uniform_int_copy(grp, "samplesLen", max_slice);
+  DRW_shgroup_uniform_float_copy(grp, "stepLength", step_length);
+  DRW_shgroup_uniform_float_copy(grp, "noiseOfs", noise_ofs);
+  DRW_shgroup_state_enable(grp, DRW_STATE_CULL_FRONT);
+
+  DRW_shgroup_uniform_texture(grp, "densityTexture", grid->texture);
+  /* TODO: implement shadow texture, see manta_smoke_calc_transparency. */
+  DRW_shgroup_uniform_texture(grp, "shadowTexture", txl->dummy_shadow_tx);
+  DRW_shgroup_uniform_vec3_copy(grp, "activeColor", color);
+
+  DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &dtxl->depth);
+  DRW_shgroup_uniform_float_copy(grp, "densityScale", density_scale);
+
+  DRW_shgroup_uniform_mat4(grp, "volumeObjectToTexture", grid->object_to_texture);
+  DRW_shgroup_uniform_mat4(grp, "volumeTextureToObject", grid->texture_to_object);
+
+  DRW_shgroup_call(grp, DRW_cache_cube_get(), ob);
+}
+
+void workbench_volume_cache_populate(WORKBENCH_Data *vedata,
+                                     Scene *UNUSED(scene),
+                                     Object *ob,
+                                     ModifierData *md,
+                                     eV3DShadingColorType color_type)
+{
+  if (md == NULL) {
+    workbench_volume_object_cache_populate(vedata, ob, color_type);
+  }
+  else {
+    workbench_volume_modifier_cache_populate(vedata, ob, md);
+  }
+}
+
 void workbench_volume_draw_pass(WORKBENCH_Data *vedata)
 {
   WORKBENCH_PassList *psl = vedata->psl;
@@ -189,4 +294,4 @@ void workbench_volume_draw_finish(WORKBENCH_Data *vedata)
     GPU_free_smoke(mmd);
   }
   BLI_freelistN(&wpd->smoke_domains);
-}
\ No newline at end of file
+}