Question by NymThePseudo · Dec 07, 2016 at 05:49 AM · culling near

How to not render objects within certain distance of camera?

I'm working on a project where it might be preferable to not render certain objects (on a specific layer) if they're within a certain distance of the camera. I know I could technically achieve this with a script, but seeing how this should apply to thousands of objects at the same time (grass for example), I was wondering whether this would be possible to do in a different, more efficient way?

Would a shader work? I'm not very good at writing shaders myself, so it would be nice if such a shader could be found somewhere. Or is there a way of doing it with built-in Unity functionality?

So yeah, I'm basically looking for the opposite of layerCullDistances, however in my case I can't just move the near clip plane.

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getyour411 · Dec 07, 2016 at 06:01 AM 0

What's the criteria for "might be"?

JedBeryll · Dec 07, 2016 at 06:31 AM 0

Interesting question. I know you said scripts may be slow but it's pretty easy to test. You would only have to calculate the squared magnitude. For efficiency, create a static reference to the main camera's transform, and a local reference to the object's own transforms. Then just compare the squared distance to the squared range that you want to test, if object passes outside, turn off renderer, otherwise turn it on. I think it's worth a try.

JedBeryll · Dec 07, 2016 at 06:34 AM 0

Another idea: lod levels. Unity already handles lod levels pretty well, so maybe just create a lod that is a cube or nothing at all (if that's even possible).

tomekkie2 · Dec 07, 2016 at 07:02 AM 0

You could use a clipping shader. Then you could define clipping surfaces like planes or spheres, and code this shader so it doesn't render between these surfaces. But objects that are cut by these surfaces will be partially rendered, i.e. clipped.