Three.js particle system as background forced behind other objects?

Question

I have a particle system that I am using to generate background stars - I have it tracking position with the camera but sometimes, the stars will render closer than the bodies which they are meant to be the background for.

Is there a way to force the particle system to always render behind the other meshes in my scene (almost as a background wallpaper - but moving with rotation)?

Many thanks.

Answer 1

This is relatively easily.

• create a renderer with autoclear = false
• clear your render with renderer.clear();
• render your particle system as a separate scene
• clear the depth of the rendering with renderer.clear(false, true, false);
• then render all other objects.

And voila, you have a particle system that always stays behind the scene.

http://jsfiddle.net/vuQ9R/10/