Tracking: Warn when no tracks are selected when creating mesh

Makes it more clear why mesh was not created this way.

Fixes T54368: 3D markers to mesh In MovieClipEditor Not working.

1 files changed, 6 insertions, 7 deletions

diff --git a/release/scripts/startup/bl_operators/clip.py b/release/scripts/startup/bl_operators/clip.py
index 6356121cffd..d70808ac963 100644
--- a/release/scripts/startup/bl_operators/clip.py
+++ b/release/scripts/startup/bl_operators/clip.py
@@ -301,20 +301,19 @@ class CLIP_OT_bundles_to_mesh(Operator):
             reconstructed_matrix = reconstruction.cameras.matrix_from_frame(framenr)
             matrix = camera.matrix_world * reconstructed_matrix.inverted()
 
-        mesh = bpy.data.meshes.new(name="Tracks")
         for track in tracking_object.tracks:
             if track.has_bundle and track.select == True:
                 new_verts.append(track.bundle)
 
         if new_verts:
+            mesh = bpy.data.meshes.new(name="Tracks")
             mesh.vertices.add(len(new_verts))
             mesh.vertices.foreach_set("co", unpack_list(new_verts))
-
-        ob = bpy.data.objects.new(name="Tracks", object_data=mesh)
-
-        ob.matrix_world = matrix
-
-        context.scene.objects.link(ob)
+            ob = bpy.data.objects.new(name="Tracks", object_data=mesh)
+            ob.matrix_world = matrix
+            context.scene.objects.link(ob)
+        else:
+            self.report({'WARNING'}, "No usable tracks selected")
 
         return {'FINISHED'}