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, 3 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_context.h b/source/blender/blenkernel/BKE_context.h
index 30ac310c2df..4da6a61cbfa 100644
--- a/source/blender/blenkernel/BKE_context.h
+++ b/source/blender/blenkernel/BKE_context.h
@@ -39,6 +39,7 @@ extern "C" {
 
 struct ARegion;
 struct bScreen;
+struct CacheFile;
 struct ListBase;
 struct Main;
 struct Object;
@@ -271,6 +272,8 @@ struct Text *CTX_data_edit_text(const bContext *C);
 struct MovieClip *CTX_data_edit_movieclip(const bContext *C);
 struct Mask *CTX_data_edit_mask(const bContext *C);
 
+struct CacheFile *CTX_data_edit_cachefile(const bContext *C);
+
 int CTX_data_selected_nodes(const bContext *C, ListBase *list);
 
 struct EditBone *CTX_data_active_bone(const bContext *C);