Alembic import: changing cache modifier path no longer discards object paths

This allows, for example, the path of an Alembic file to be changed from
absolute to relative, without having to reconstruct all object paths.

2 files changed, 37 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/cachefile.c b/source/blender/blenkernel/intern/cachefile.c
index ff0a776aa82..67c66d4e40b 100644
--- a/source/blender/blenkernel/intern/cachefile.c
+++ b/source/blender/blenkernel/intern/cachefile.c
@@ -221,7 +221,6 @@ void BKE_cachefile_clean(Scene *scene, CacheFile *cache_file)
 				}
 #endif
 				mcmd->reader = NULL;
-				mcmd->object_path[0] = '\0';
 			}
 		}
 
@@ -239,7 +238,6 @@ void BKE_cachefile_clean(Scene *scene, CacheFile *cache_file)
 				}
 #endif
 				data->reader = NULL;
-				data->object_path[0] = '\0';
 			}
 		}
 	}
diff --git a/tests/python/bl_alembic_import_test.py b/tests/python/bl_alembic_import_test.py
index cd23183ec06..33ccc49f301 100644
--- a/tests/python/bl_alembic_import_test.py
+++ b/tests/python/bl_alembic_import_test.py
@@ -85,6 +85,43 @@ class SimpleImportTest(unittest.TestCase):
         for ob in bpy.data.objects:
             self.assertEqual('Cube' in ob.name, ob.select)
 
+    def test_change_path(self):
+        import math
+
+        fname = 'cube-rotating1.abc'
+        abc = self.testdir / fname
+        relpath = bpy.path.relpath(str(abc))
+
+        res = bpy.ops.wm.alembic_import(filepath=str(abc), as_background_job=False)
+        self.assertEqual({'FINISHED'}, res)
+        cube = bpy.context.active_object
+
+        # Check that the file loaded ok.
+        bpy.context.scene.frame_set(10)
+        x, y, z = cube.matrix_world.to_euler('XYZ')
+        self.assertAlmostEqual(x, 0)
+        self.assertAlmostEqual(y, 0)
+        self.assertAlmostEqual(z, math.pi / 2, places=5)
+
+        # Change path from absolute to relative. This should not break the animation.
+        bpy.context.scene.frame_set(1)
+        bpy.data.cache_files[fname].filepath = relpath
+        bpy.context.scene.frame_set(10)
+
+        x, y, z = cube.matrix_world.to_euler('XYZ')
+        self.assertAlmostEqual(x, 0)
+        self.assertAlmostEqual(y, 0)
+        self.assertAlmostEqual(z, math.pi / 2, places=5)
+
+        # Replace the Alembic file; this should apply new animation.
+        bpy.data.cache_files[fname].filepath = relpath.replace('1.abc', '2.abc')
+        bpy.context.scene.update()
+
+        x, y, z = cube.matrix_world.to_euler('XYZ')
+        self.assertAlmostEqual(x, math.pi / 2, places=5)
+        self.assertAlmostEqual(y, 0)
+        self.assertAlmostEqual(z, 0)
+
 
 def main():
     global args