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, 26 insertions, 6 deletions

diff --git a/source/blender/alembic/intern/abc_points.cc b/source/blender/alembic/intern/abc_points.cc
index 03014547416..c16da621c77 100644
--- a/source/blender/alembic/intern/abc_points.cc
+++ b/source/blender/alembic/intern/abc_points.cc
@@ -32,6 +32,7 @@ extern "C" {
 #include "DNA_mesh_types.h"
 #include "DNA_object_types.h"
 
+#include "BKE_cdderivedmesh.h"
 #include "BKE_lattice.h"
 #include "BKE_mesh.h"
 #include "BKE_object.h"
@@ -154,14 +155,14 @@ void AbcPointsReader::readObjectData(Main *bmain, float time)
 {
 	Mesh *mesh = BKE_mesh_add(bmain, m_data_name.c_str());
 
-	const ISampleSelector sample_sel(time);
-	m_sample = m_schema.getValue(sample_sel);
+	DerivedMesh *dm = CDDM_from_mesh(mesh);
+	DerivedMesh *ndm = this->read_derivedmesh(dm, time, 0);
 
-	const P3fArraySamplePtr &positions = m_sample.getPositions();
-	utils::mesh_add_verts(mesh, positions->size());
+	if (ndm != dm) {
+		dm->release(dm);
+	}
 
-	CDStreamConfig config = create_config(mesh);
-	read_points_sample(m_schema, sample_sel, config, time);
+	DM_to_mesh(ndm, mesh, m_object, CD_MASK_MESH, true);
 
 	if (m_settings->validate_meshes) {
 		BKE_mesh_validate(mesh, false, false);
@@ -197,3 +198,22 @@ void read_points_sample(const IPointsSchema &schema,
 
 	read_mverts(config.mvert, positions, vnormals);
 }
+
+DerivedMesh *AbcPointsReader::read_derivedmesh(DerivedMesh *dm, const float time, int /*read_flag*/)
+{
+	ISampleSelector sample_sel(time);
+	const IPointsSchema::Sample sample = m_schema.getValue(sample_sel);
+
+	const P3fArraySamplePtr &positions = sample.getPositions();
+
+	DerivedMesh *new_dm = NULL;
+
+	if (dm->getNumVerts(dm) != positions->size()) {
+		new_dm = CDDM_new(positions->size(), 0, 0, 0, 0);
+	}
+
+	CDStreamConfig config = get_config(new_dm ? new_dm : dm);
+	read_points_sample(m_schema, sample_sel, config, time);
+
+	return new_dm ? new_dm : dm;
+}