Alembic: store a pointer to the object reader in the cache modifiers and

constraints.

This avoids traversing the archive everytime object data is needed and
gives an overall consistent ~2x speedup here with files containing
between 136 and 500 Alembic objects. Also this somewhat nicely de-
duplicates code between data creation (upon import) and data streaming
(modifiers and constraints).

The only worying part is what happens when a CacheFile is deleted and/or
has its path changed. For now, we traverse the whole scene and for each
object using the CacheFile we free the pointer and NULL-ify it (see
BKE_cachefile_clean), but at some point this should be re-considered and
make use of the dependency graph.

1 files changed, 20 insertions, 1 deletions

diff --git a/source/blender/makesrna/intern/rna_constraint.c b/source/blender/makesrna/intern/rna_constraint.c
index db3f76f3cfc..ad037af943d 100644
--- a/source/blender/makesrna/intern/rna_constraint.c
+++ b/source/blender/makesrna/intern/rna_constraint.c
@@ -148,12 +148,17 @@ static EnumPropertyItem space_object_items[] = {
 	{0, NULL, 0, NULL, NULL}
 };
 
+#include "DNA_cachefile_types.h"
+
 #include "BKE_animsys.h"
 #include "BKE_action.h"
 #include "BKE_constraint.h"
 #include "BKE_context.h"
 #include "BKE_depsgraph.h"
 
+#ifdef WITH_ALEMBIC
+#  include "ABC_alembic.h"
+#endif
 
 static StructRNA *rna_ConstraintType_refine(struct PointerRNA *ptr)
 {
@@ -471,6 +476,20 @@ static void rna_Constraint_objectSolver_camera_set(PointerRNA *ptr, PointerRNA v
 	}
 }
 
+static void rna_Constraint_transformCache_object_path_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+{
+	bConstraint *con = (bConstraint *)ptr->data;
+	bTransformCacheConstraint *data = (bTransformCacheConstraint *)con->data;
+	Object *ob = (Object *)ptr->id.data;
+
+	data->reader = CacheReader_open_alembic_object(data->cache_file->handle,
+	                                               data->reader,
+	                                               ob,
+	                                               data->object_path);
+
+	rna_Constraint_update(bmain, scene, ptr);
+}
+
 #else
 
 static EnumPropertyItem constraint_distance_items[] = {
@@ -2593,7 +2612,7 @@ static void rna_def_constraint_transform_cache(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "object_path", PROP_STRING, PROP_NONE);
 	RNA_def_property_ui_text(prop, "Object Path", "Path to the object in the Alembic archive used to lookup the transform matrix");
-	RNA_def_property_update(prop, 0, "rna_Constraint_update");
+	RNA_def_property_update(prop, 0, "rna_Constraint_transformCache_object_path_update");
 }
 
 /* base struct for constraints */