v1.6.0

Added

• Added ability to add and remove objects in real-time after viewer starts running.
• Added option to drag and drop serialized JSON files of scene and geometries.
• Added shortcut Del to remove selected objects in scene.
• Added OffscreenBufferContext for better maintainability on instance rendering pipeline.

Changed

• Made linewidth working again through GeometryShader.
• Fixed a bug of viewer crashing with empty scene.

Removed