How to render twice per frame with two different cull face modes?

Hello! I’m new to three.js :slight_smile:
I want to do a render with ‘CullFaceFront’ mode, then do another render with ‘CullFaceBack’ mode on top of the first render, do the two renders per frame, any idea?

You can do this by modifying the side property of all materials in your scene. Meaning in the first pass you use THREE.FrontSide, in the second pass you use THREE.BackSide. When changing the side property, you have to set the needsUpdate flag of the materials to true.

Since you call WebGLRenderer.render() more than once to produce a frame, you have to set the renderer’s autoUpdate property to false and perform the clear manually via renderer.clear() at the beginning of your render loop.

Aha,it works very well,thanks a lot!