Blender instance question .draw call multi time

Hi ~ I have multiple instance “studio_door_left/right_xxx” in my .glb file created in Blender

but one instance need 2 draw call.
I also try to use scene.useRightHandedSystem = true
But it doesn’t seem to affect the number of draw calls . still 40 draw calls


That’s because your master mesh has a x scaling of -1 and your instances have a scaling of 1. More precisely, 8 instances over 10 have a scaling of 1 and 2 a scaling of -1. So, only 2 instances can be batched with their corresponding master mesh and all other instances need one draw call each. You should update your blender file to have the same scaling for all instances.