Basic Alembic support

All in all, this patch adds an Alembic importer, an Alembic exporter,
and a new CacheFile data block which, for now, wraps around an Alembic
archive. This data block is made available through a new modifier ("Mesh
Sequence Cache") as well as a new constraint ("Transform Cache") to
somewhat properly support respectively geometric and transformation data
streaming from alembic caches.

A more in-depth documentation is to be found on the wiki, as well as a
 guide to compile alembic: https://wiki.blender.org/index.php/
User:Kevindietrich/AlembicBasicIo.

Many thanks to everyone involved in this little project, and huge shout
out to "cgstrive" for the thorough testings with Maya, 3ds Max, Houdini
and Realflow as well as @fjuhec, @jensverwiebe and @jasperge for the
custom builds and compile fixes.

Reviewers: sergey, campbellbarton, mont29

Reviewed By: sergey, campbellbarton, mont29

Differential Revision: https://developer.blender.org/D2060

1 files changed, 17 insertions, 0 deletions

diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index fb31cd227ba..b6a54715763 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -107,6 +107,7 @@
 #include "DNA_armature_types.h"
 #include "DNA_actuator_types.h"
 #include "DNA_brush_types.h"
+#include "DNA_cachefile_types.h"
 #include "DNA_camera_types.h"
 #include "DNA_cloth_types.h"
 #include "DNA_constraint_types.h"
@@ -3882,6 +3883,21 @@ static void write_linestyles(WriteData *wd, ListBase *idbase)
 	}
 }
 
+static void write_cachefiles(WriteData *wd, ListBase *idbase)
+{
+	CacheFile *cache_file;
+
+	for (cache_file = idbase->first; cache_file; cache_file = cache_file->id.next) {
+		if (cache_file->id.us > 0 || wd->current) {
+			writestruct(wd, ID_CF, CacheFile, 1, cache_file);
+
+			if (cache_file->adt) {
+				write_animdata(wd, cache_file->adt);
+			}
+		}
+	}
+}
+
 /* Keep it last of write_foodata functions. */
 static void write_libraries(WriteData *wd, Main *main)
 {
@@ -4079,6 +4095,7 @@ static bool write_file_handle(
 	write_paintcurves(wd, &mainvar->paintcurves);
 	write_gpencils(wd, &mainvar->gpencil);
 	write_linestyles(wd, &mainvar->linestyle);
+	write_cachefiles(wd, &mainvar->cachefiles);
 	write_libraries(wd,  mainvar->next);
 
 	/* So changes above don't cause a 'DNA1' to be detected as changed on undo. */