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Reflection Clipping Problem

Hi,

We are seeing our screen space reflections abruptly disappear in the distance. Is there a way to adjust the distance at which SSR clips out?

The scene we’re working on is a model of Portland, Oregon, where the river and bridges are the main actors. Notice how the first bridge has a decent reflection in our water material, but with the second and third bridges, the reflections disappear. Reflection planes and ray-tracing are great, but too expensive for real-time in our scene.

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Anybody? Why do reflections seem to simply stop at some point in the distance???

I think the reason there’s a cutoff is that the “real” reflection should show what’s “behind” the things that are in front, but obviously they’re not there. For example, if you lowered the camera just a little, the second bridge would, in screen space “reflect” the towers of the first bridge, which is obviously incorrect. My guess is that the distance cut-off is to reduce such artifacts.

For that river, specifically, I would suggest using a planar reflection in plane with the river surface – it’s an almost perfect use case for this feature!

For other cases, strategically placed reflection captures may help improve things, although you may have to tweak things like capture distance and maybe even turn off SSR.

To get reflections to be physically correct, though, you need to turn on ray tracing, with all the additional complexities and requirements that that involves.