Reflections in Second Life

[BjRazzz Qinan]

A very long time ago there were Dynamic Reflections in Second Life as spoken of in this blog from 2007: Render Dynamic Reflections

Is there anything like this presently in the viewer?

[Fritigern Gothly]

Dynamic reflections, although possible, were decided against because of technical reasons. You see, each reflection needs to be calculated on the server, the server needs to put an exact copy of the reflected scene in its memory, then each of these copies need to be calculated, rendered, and fed to the viewer and pray that the user has the memory and the graphics card to deal with all this extra stuff it needs to render.

Even if you were to limit the reflections per mirror to, let's say, four. That would mean that 4 copies of the region the mirror is in needs to be held in the server's memory, calculated, etc. 

Now imagine some joker placing 2 mirrors in front of each other, reflecting each other's reflections.
Now imagine this same joker repeating this process 100 times in a sandbox or some place on mainland where someone forgot to restrict building.

And even if someone does not intentionally starts griefing with these mirrors, it is still possible that someone accidentally starts causing issues by placing a mirror on the wall in full view of their vanity...

I'm sure you can see now why dynamic reflections are a bad idea for SL, but I agree, it would have been nice to have them. But it is not a good idea.

[BjRazzz Qinan]

46 minutes ago, Fritigern Gothly said:

it would have been nice to have them. But it is not a good idea.

Yes, it would have. I fully agree with your break down though.

Edited March 22, 2021 by BjRazzz Qinan

[panterapolnocy]

3 hours ago, Fritigern Gothly said:

You see, each reflection needs to be calculated on the server

That is slightly not true, I guess. Rendering is done in the viewer - if viewer has all of the objects' positions, then can invert them and put inside a rendered mirror. Server has nothing to do with it. Mirrors as a concept / tech demo was done already - see https://jira.secondlife.com/browse/STORM-2055 - its "only" issue was that it didn't work with ALM enabled, worked only on flat surfaces and had some small bugs here and there. Other than that, they worked pretty well.

You may also want to see https://modemworld.me/2018/05/12/projectors-as-mirrors-in-second-life/ and https://modemworld.me/2014/08/06/reflections-on-a-prim-a-potential-way-to-create-mirrors-in-sl/

Edited March 22, 2021 by panterapolnocy

[BjRazzz Qinan]

5 hours ago, panterapolnocy said:

its "only" issue was that it didn't work with ALM enabled

what is ALM and what about the new GPUs for raytracing from NVIDIA and AMD.

Edited March 22, 2021 by BjRazzz Qinan

[Solar Legion]

48 minutes ago, BjRazzz Qinan said:

what is ALM and what about the new GPUs for raytracing from NVIDIA and AMD.

Advanced Lighting Model - that's the function that allows you to see Shadows, Materials, Point Lights, Projectors and pretty much all of the newer visual shiny things.

Second Life is not coded to make use of RTX functions.

[BjRazzz Qinan]

RTX is a little too new. I didn't expect SL was up to using RTX functions.

Maybe something for the future when Ray-tracing is less niche and more accessible.

Edited March 22, 2021 by BjRazzz Qinan

[Rachel1206]

Raytracing would put a considerable overhead on performance in SL and notice even full HD with raytracing really requires like GTX 3070 or more expensive high end graphic cards in optimzed AAA games.

And clever usage of creators on materials and UV maps really show how good Second Lise is with Advanced Light Modelling (ALM) and gives eftects like reflections. Impressive and excellent work in the SL engine by Linden Lab.Try and visit some high end quality regions with grahics set to ultra and all the bells and whistles on. Done right by the creators/builders even good high FPS is maintained.

To me, it shows the old lady (Second Life) still sings!