How to change view port size?

General
1

For example, I want to draw my scene on the left top corner area of the canvas.
Thanks.

2

This would require some css/html styling. You could assign a position css property to the scene and tell it to go to the top left corner of the canvas like in the last example in that link.

3

I wanted the same function as this link.
https://threejs.org/docs/#api/en/renderers/WebGLRenderer.setViewport
solved my self