I want to use the frustum of the specified area to exclude the mesh outside the frustum, similar to setViewOffset in threeJs, does BJS have a similar method?
Hello @ZoeLeee , how are you doing?
Maybe you can set the camera’s viewport property to the area you wish the frustum to be and them call camera.isCompletelyInFrustum or camera.isInFrustum.
If you need extra help, can you please setup a Playground with an example?
Hello! Just checking in if you still have questions @ZoeLeee
Hello , how are you doing?
This is PG, the ideal state is to only display the content of the viewport, but actually the entire scene is zoomed into the viewport.
This is the main idea about viewport 
it defines the zone where the render will be visible. If you only want a zone being visible, I guess you are willing to use scissor instead ?