Click on the question-mark item for say Reflection Probes - you get taken to the base, built-in graphics, docs which is not very helpful since options are different for most components in HDRP. It should go to Reflection Probe | High Definition RP | 10.2.2 (unity3d.com) in this instance.
if it’s a mystery, I would suggest looking at the new HDRP scene template. It uses several reflection proxies (assigned to reflection probes) to ensure the probes are correctly “distorted” in the volume set by the proxy and based on the camera position. If you still have trouble understanding how it works after this, let us know.
Regarding “infinite”, this won’t distort the probe at all, so it will look as if the reflection follows the camera. Again, playing with the new HDRP template should make it quite clear, I hope.
Yes it does thanks. The last part of the docs is clear actually - maybe should be in bold - use a proxy for much more accurate reflections at potential price of distortion!
You can get some quite excessive distortion on box proxies
In that demo the reflective spheres do not appear in reflections, as you would want, but if you had a number of spheres around the room or it was an interior with lots of chrome, this is not an option, so I guess all of this is just smoke and mirrors until we can use real time raytracing for all reflections (which are there, but hardware…)
Side note: with motion blur off, the TAA seems to still cause motion blur and even distortion on the plants in particular, AA is tricky…
The capture point for the reflection applied to that sphere is a couple of meters away, so it’s normal you won’t get a perfect reflection on the sphere.
There is always a tradeoff between placing a ton of probes, blending between them, and performance.
Also, blending nicely between probes when dealing with mirror surfaces is a complex setup issue. It’s actually often more pleasing to have one giant reflection that is slightly incorrect, rather than a ton of accurate probes trying to blend together and creating a blurry mess between each reflection probe volume.
If you wanted more correct reflections on that specific object, you could just place another reflection probe with a small radius inside the Unity sphere, tag the sphere to not be seen by the reflection probe, and bake it. Now you’d get accurate reflections from the point of view of the sphere, giving pretty much ray-traced-like quality (except for self-reflection, and being limited by the reflection probe’s resolution).
That depends entirely on your project requirements indeed, but this technique is widely used, and it hasn’t prevented anyone from shipping games for more than a decade using reflection probes.
So basically Reflection Proxy Volume is just used for distortion of reflection probe. (zooming in/out, in particular direction kind of thingy ?)
There is no additional relation between reflection probes inside (interpolation etc…).
So when there are multiple Reflection Probes connected to the same Reflection Proxy Volume it would give us the same result as if each Reflection probe got it’s own Reflection Proxy Volume.
