Merge remote-tracking branch 'origin/blender-v2.83-release'

source/blender/io/alembic/intern/abc_customdata.cc

@@ -144,7 +144,7 @@ const char *get_uv_sample(UVSample &sample, const CDStreamConfig &config, Custom
  * - (optional due to its behavior) tag as UV using Alembic::AbcGeom::SetIsUV
  */
 static void write_uv(const OCompoundProperty &prop,
-                     const CDStreamConfig &config,
+                     CDStreamConfig &config,
                      void *data,
                      const char *name)
 {
@@ -157,13 +157,18 @@ static void write_uv(const OCompoundProperty &prop,
     return;
   }
 
-  OV2fGeomParam param(prop, name, true, kFacevaryingScope, 1);
+  std::string uv_map_name(name);
+  OV2fGeomParam param = config.abc_uv_maps[uv_map_name];
 
+  if (!param.valid()) {
+    param = OV2fGeomParam(prop, name, true, kFacevaryingScope, 1);
+  }
   OV2fGeomParam::Sample sample(V2fArraySample(&uvs.front(), uvs.size()),
                                UInt32ArraySample(&indices.front(), indices.size()),
                                kFacevaryingScope);
-
   param.set(sample);
+
+  config.abc_uv_maps[uv_map_name] = param;
 }
 
 /* Convention to write Vertex Colors:
@@ -217,7 +222,7 @@ static void write_mcol(const OCompoundProperty &prop,
 }
 
 void write_custom_data(const OCompoundProperty &prop,
-                       const CDStreamConfig &config,
+                       CDStreamConfig &config,
                        CustomData *data,
                        int data_type)
 {

source/blender/io/alembic/intern/abc_customdata.h

@@ -27,6 +27,8 @@
 #include <Alembic/Abc/All.h>
 #include <Alembic/AbcGeom/All.h>
 
+#include <map>
+
 struct CustomData;
 struct MLoop;
 struct MLoopUV;
@@ -70,6 +72,12 @@ struct CDStreamConfig {
 
   const char **modifier_error_message;
 
+  /* Alembic needs Blender to keep references to C++ objects (the destructors
+   * finalise the writing to ABC). This map stores OV2fGeomParam objects for the
+   * 2nd and subsequent UV maps; the primary UV map is kept alive by the Alembic
+   * mesh sample itself. */
+  std::map<std::string, Alembic::AbcGeom::OV2fGeomParam> abc_uv_maps;
+
   CDStreamConfig()
       : mloop(NULL),
         totloop(0),
@@ -95,7 +103,7 @@ struct CDStreamConfig {
 const char *get_uv_sample(UVSample &sample, const CDStreamConfig &config, CustomData *data);
 
 void write_custom_data(const OCompoundProperty &prop,
-                       const CDStreamConfig &config,
+                       CDStreamConfig &config,
                        CustomData *data,
                        int data_type);