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

1 files changed, 120 insertions, 15 deletions

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
+}