Cycles: experimental integration of Alembic procedural in viewport rendering

This patch exposes the Cycles Alembic Procedural through the MeshSequenceCache
modifier in order to use and test it from Blender.

To enable it, one has to switch the render feature set to experimental and
activate the Procedural in the modifier. An Alembic Procedural is then
created for each CacheFile from Blender set to use the Procedural, and each
Blender object having a MeshSequenceCache modifier is added to list of objects
of the right procedural.

The procedural's parameters derive from the CacheFile's properties which are
already exposed in the UI through the modifier, although more Cycles specific
options might be added in the future.

As there is currently no cache controls and since we load all the data at the
beginning of the render session, the procedural is only available during
viewport renders at the moment. When an Alembic procedural is rendered, data
from the archive are not read on the Blender side.

If a Cycles render is not active and the CacheFile is set to use the Cycles Procedural,
bounding boxes are used to display the objects in the scene as a signal that the
objects are not processed by Blender anymore. This is standard in other DCCs.
However this does not reduce the memory usage from Blender as the Alembic data
was already loaded either during an import or during a .blend file read.

This is mostly a hack to test the Cycles Alembic procedural until we have a
better Blender side mechanism for letting renderers load their own geometry,
which will be based on import and export settings on Collections (T68933).

Ref T79174, D3089

Reviewed By: brecht, sybren

Maniphest Tasks: T79174

Differential Revision: https://developer.blender.org/D10197

17 files changed, 97 insertions, 18 deletions

diff --git a/source/blender/modifiers/intern/MOD_build.c b/source/blender/modifiers/intern/MOD_build.c
index 52f21e3d3d0..a344a15b0c1 100644
--- a/source/blender/modifiers/intern/MOD_build.c
+++ b/source/blender/modifiers/intern/MOD_build.c
@@ -61,7 +61,9 @@ static void initData(ModifierData *md)
   MEMCPY_STRUCT_AFTER(bmd, DNA_struct_default_get(BuildModifierData), modifier);
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_cloth.c b/source/blender/modifiers/intern/MOD_cloth.c
index 4487adcfdda..fa2f70e1a9c 100644
--- a/source/blender/modifiers/intern/MOD_cloth.c
+++ b/source/blender/modifiers/intern/MOD_cloth.c
@@ -220,7 +220,9 @@ static void copyData(const ModifierData *md, ModifierData *target, const int fla
   tclmd->solver_result = NULL;
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_collision.c b/source/blender/modifiers/intern/MOD_collision.c
index 5dd57469914..e7d5fe056c5 100644
--- a/source/blender/modifiers/intern/MOD_collision.c
+++ b/source/blender/modifiers/intern/MOD_collision.c
@@ -95,7 +95,9 @@ static void freeData(ModifierData *md)
   }
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_displace.c b/source/blender/modifiers/intern/MOD_displace.c
index a7ac9f618af..07da18f990d 100644
--- a/source/blender/modifiers/intern/MOD_displace.c
+++ b/source/blender/modifiers/intern/MOD_displace.c
@@ -95,7 +95,9 @@ static void requiredDataMask(Object *UNUSED(ob),
   }
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *md,
+                          const int UNUSED(dag_eval_mode))
 {
   DisplaceModifierData *dmd = (DisplaceModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_dynamicpaint.c b/source/blender/modifiers/intern/MOD_dynamicpaint.c
index 8b1d541d45d..77ae5c4b6f1 100644
--- a/source/blender/modifiers/intern/MOD_dynamicpaint.c
+++ b/source/blender/modifiers/intern/MOD_dynamicpaint.c
@@ -155,7 +155,9 @@ static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphConte
   }
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_explode.c b/source/blender/modifiers/intern/MOD_explode.c
index bf197dca7e5..493b59b3a1a 100644
--- a/source/blender/modifiers/intern/MOD_explode.c
+++ b/source/blender/modifiers/intern/MOD_explode.c
@@ -86,7 +86,9 @@ static void copyData(const ModifierData *md, ModifierData *target, const int fla
 
   temd->facepa = NULL;
 }
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_fluid.c b/source/blender/modifiers/intern/MOD_fluid.c
index 36d2ab2a11a..a14d582063a 100644
--- a/source/blender/modifiers/intern/MOD_fluid.c
+++ b/source/blender/modifiers/intern/MOD_fluid.c
@@ -132,7 +132,9 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 #endif /* WITH_FLUID */
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_meshcache.c b/source/blender/modifiers/intern/MOD_meshcache.c
index e0507320628..6ef64ad8bc9 100644
--- a/source/blender/modifiers/intern/MOD_meshcache.c
+++ b/source/blender/modifiers/intern/MOD_meshcache.c
@@ -63,7 +63,9 @@ static void initData(ModifierData *md)
   MEMCPY_STRUCT_AFTER(mcmd, DNA_struct_default_get(MeshCacheModifierData), modifier);
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *md,
+                          const int UNUSED(dag_eval_mode))
 {
   MeshCacheModifierData *mcmd = (MeshCacheModifierData *)md;
   return (mcmd->play_mode == MOD_MESHCACHE_PLAY_CFEA);
diff --git a/source/blender/modifiers/intern/MOD_meshsequencecache.c b/source/blender/modifiers/intern/MOD_meshsequencecache.c
index 3e6081e0a18..2aa76c18c83 100644
--- a/source/blender/modifiers/intern/MOD_meshsequencecache.c
+++ b/source/blender/modifiers/intern/MOD_meshsequencecache.c
@@ -20,6 +20,7 @@
 
 #include <string.h>
 
+#include "BLI_math_vector.h"
 #include "BLI_string.h"
 #include "BLI_utildefines.h"
 
@@ -39,6 +40,8 @@
 #include "BKE_cachefile.h"
 #include "BKE_context.h"
 #include "BKE_lib_query.h"
+#include "BKE_mesh.h"
+#include "BKE_object.h"
 #include "BKE_scene.h"
 #include "BKE_screen.h"
 
@@ -118,6 +121,44 @@ static bool isDisabled(const struct Scene *UNUSED(scene),
   return (mcmd->cache_file == NULL) || (mcmd->object_path[0] == '\0');
 }
 
+static Mesh *generate_bounding_box_mesh(Object *object, Mesh *org_mesh)
+{
+  BoundBox *bb = BKE_object_boundbox_get(object);
+  Mesh *result = BKE_mesh_new_nomain_from_template(org_mesh, 8, 0, 0, 24, 6);
+
+  MVert *mvert = result->mvert;
+  for (int i = 0; i < 8; ++i) {
+    copy_v3_v3(mvert[i].co, bb->vec[i]);
+  }
+
+  /* See DNA_object_types.h for the diagram showing the order of the vertices for a BoundBox. */
+  static unsigned int loops_v[6][4] = {
+      {0, 4, 5, 1},
+      {4, 7, 6, 5},
+      {7, 3, 2, 6},
+      {3, 0, 1, 2},
+      {1, 5, 6, 2},
+      {3, 7, 4, 0},
+  };
+
+  MLoop *mloop = result->mloop;
+  for (int i = 0; i < 6; ++i) {
+    for (int j = 0; j < 4; ++j, ++mloop) {
+      mloop->v = loops_v[i][j];
+    }
+  }
+
+  MPoly *mpoly = result->mpoly;
+  for (int i = 0; i < 6; ++i) {
+    mpoly[i].loopstart = i * 4;
+    mpoly[i].totloop = 4;
+  }
+
+  BKE_mesh_calc_edges(result, false, false);
+
+  return result;
+}
+
 static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mesh)
 {
 #if defined(WITH_USD) || defined(WITH_ALEMBIC)
@@ -143,6 +184,12 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
     }
   }
 
+  /* Do not process data if using a render procedural, return a box instead for displaying in the
+   * viewport. */
+  if (BKE_cache_file_uses_render_procedural(cache_file, scene, DEG_get_mode(ctx->depsgraph))) {
+    return generate_bounding_box_mesh(ctx->object, org_mesh);
+  }
+
   /* If this invocation is for the ORCO mesh, and the mesh hasn't changed topology, we
    * must return the mesh as-is instead of deforming it. */
   if (ctx->flag & MOD_APPLY_ORCO) {
@@ -228,11 +275,13 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 #endif
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(Scene *scene, ModifierData *md, const int dag_eval_mode)
 {
 #if defined(WITH_USD) || defined(WITH_ALEMBIC)
   MeshSeqCacheModifierData *mcmd = (MeshSeqCacheModifierData *)md;
-  return (mcmd->cache_file != NULL);
+  /* Do not evaluate animations if using the render engine procedural. */
+  return (mcmd->cache_file != NULL) &&
+         !BKE_cache_file_uses_render_procedural(mcmd->cache_file, scene, dag_eval_mode);
 #else
   UNUSED_VARS(md);
   return false;
diff --git a/source/blender/modifiers/intern/MOD_softbody.c b/source/blender/modifiers/intern/MOD_softbody.c
index d7d2f948955..4187f9087a0 100644
--- a/source/blender/modifiers/intern/MOD_softbody.c
+++ b/source/blender/modifiers/intern/MOD_softbody.c
@@ -62,7 +62,9 @@ static void deformVerts(ModifierData *UNUSED(md),
       ctx->depsgraph, scene, ctx->object, DEG_get_ctime(ctx->depsgraph), vertexCos, numVerts);
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_surface.c b/source/blender/modifiers/intern/MOD_surface.c
index bfd4cd81803..3f2d0a06db8 100644
--- a/source/blender/modifiers/intern/MOD_surface.c
+++ b/source/blender/modifiers/intern/MOD_surface.c
@@ -98,7 +98,9 @@ static void freeData(ModifierData *md)
   }
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_volume_displace.cc b/source/blender/modifiers/intern/MOD_volume_displace.cc
index af4b31d6bfc..dfd3fdd80f8 100644
--- a/source/blender/modifiers/intern/MOD_volume_displace.cc
+++ b/source/blender/modifiers/intern/MOD_volume_displace.cc
@@ -95,7 +95,7 @@ static void foreachTexLink(ModifierData *md, Object *ob, TexWalkFunc walk, void
   walk(userData, ob, md, "texture");
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md, const int UNUSED(dag_eval_mode))
 {
   VolumeDisplaceModifierData *vdmd = reinterpret_cast<VolumeDisplaceModifierData *>(md);
   if (vdmd->texture) {
diff --git a/source/blender/modifiers/intern/MOD_warp.c b/source/blender/modifiers/intern/MOD_warp.c
index 3bebc52c503..25e33b22bde 100644
--- a/source/blender/modifiers/intern/MOD_warp.c
+++ b/source/blender/modifiers/intern/MOD_warp.c
@@ -116,7 +116,9 @@ static void matrix_from_obj_pchan(float mat[4][4],
   }
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *md,
+                          const int UNUSED(dag_eval_mode))
 {
   WarpModifierData *wmd = (WarpModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_wave.c b/source/blender/modifiers/intern/MOD_wave.c
index cf4c195c66d..03f8e3a1dfb 100644
--- a/source/blender/modifiers/intern/MOD_wave.c
+++ b/source/blender/modifiers/intern/MOD_wave.c
@@ -70,7 +70,9 @@ static void initData(ModifierData *md)
   MEMCPY_STRUCT_AFTER(wmd, DNA_struct_default_get(WaveModifierData), modifier);
 }
 
-static bool dependsOnTime(ModifierData *UNUSED(md))
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *UNUSED(md),
+                          const int UNUSED(dag_eval_mode))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_weightvgedit.c b/source/blender/modifiers/intern/MOD_weightvgedit.c
index 093fa118ee0..a9d01c64ff1 100644
--- a/source/blender/modifiers/intern/MOD_weightvgedit.c
+++ b/source/blender/modifiers/intern/MOD_weightvgedit.c
@@ -112,7 +112,9 @@ static void requiredDataMask(Object *UNUSED(ob),
   /* No need to ask for CD_PREVIEW_MLOOPCOL... */
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *md,
+                          const int UNUSED(dag_eval_mode))
 {
   WeightVGEditModifierData *wmd = (WeightVGEditModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_weightvgmix.c b/source/blender/modifiers/intern/MOD_weightvgmix.c
index 7aae089fa18..b369b82ebb7 100644
--- a/source/blender/modifiers/intern/MOD_weightvgmix.c
+++ b/source/blender/modifiers/intern/MOD_weightvgmix.c
@@ -154,7 +154,9 @@ static void requiredDataMask(Object *UNUSED(ob),
   /* No need to ask for CD_PREVIEW_MLOOPCOL... */
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *md,
+                          const int UNUSED(dag_eval_mode))
 {
   WeightVGMixModifierData *wmd = (WeightVGMixModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_weightvgproximity.c b/source/blender/modifiers/intern/MOD_weightvgproximity.c
index 6e78774269a..7ee19e1c537 100644
--- a/source/blender/modifiers/intern/MOD_weightvgproximity.c
+++ b/source/blender/modifiers/intern/MOD_weightvgproximity.c
@@ -362,7 +362,9 @@ static void requiredDataMask(Object *UNUSED(ob),
   /* No need to ask for CD_PREVIEW_MLOOPCOL... */
 }
 
-static bool dependsOnTime(ModifierData *md)
+static bool dependsOnTime(struct Scene *UNUSED(scene),
+                          ModifierData *md,
+                          const int UNUSED(dag_eval_mode))
 {
   WeightVGProximityModifierData *wmd = (WeightVGProximityModifierData *)md;