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Which do you prefer? Rembrandt or ALS?

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Rembrandt vs. ALS

Rembrandt
7
12%
ALS
43
74%
Neither
4
7%
What are these?
4
7%
 
Total votes : 58

Re: Which do you prefer? Rembrandt or ALS?

Postby Richard » Mon Jan 18, 2016 3:18 pm

Thorsten wrote in Mon Jan 18, 2016 2:25 pm:
Unless it works over multiplayer, its pointless for me.


That goes a long way to show how different users are... different.
....
Please don't see this as a criticism in any way - you're entitled to value whatever features you like - but just as a quest for comprehension: Why is this so much more important than getting the rest of the scene right?


I know that the lack of emissive lights is not an easy problem to solve. AIUI it's either per vertex which doesn't scale to more than a couple of lights, or deferred lighting. NVidia recently published information about a new scheme that they're supporting as an extension that might work well but it's too early to tell and I rather suspect it'll be for high end hardware anyway.

What I suspect Stuart means is when taxiing, or using helicopters (search and rescue), helicopter landing etc. If you're doing a group flight then not being able to see each other or the taxiiways when you taxi in dusk is an issue. Not being able to see the ground as you come into land is quite important.

I know that some of these issues are solved nicely for the ownship by the ALS secondary lighting but in a multiplayer environment it doesn't work. Quite often Stuart will be taking screenshots or filming another player (using the selectable thing in the model view) - and the lack of lighting in this case is less than ideal.

I used to always use Rembrandt, but now I find that the overall in cockpit realism is higher with ALS and with the ALS secondary lighting it's pretty much equal. Outside it does look good to see everyone's lights.

--Richard
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Re: Which do you prefer? Rembrandt or ALS?

Postby Thorsten » Mon Jan 18, 2016 5:08 pm

I understand that if you're especially into night operations, specifically taxiing at night, then Rembrandt is what you want. But if you equip planes with position lights and lightmaps, you can always see them. Your own lights will illuminate them under the scheme we have, you just won't be illuminated by them - it's kind of a second order problem.

I mean, it's nice if you see that some other plane can illuminate you, but... that's for me really on the level of 'cool to have but nowhere crucial'. It's cool to illuminate fog and rain with a landing light for instance, but if it couldn't have been done easily, I'd never wasted much effort on it. Rembrandt doesn't really do realistic secondary lights either, it just does a different illusion strategy (they never cast shadows for instance, they don't illuminate rain,...)

I know that the lack of emissive lights is not an easy problem to solve. AIUI it's either per vertex which doesn't scale to more than a couple of lights, or deferred lighting


As the cloud shadows demonstrate, there is a third and modestly framerate-friendly way how it could be done approximately - just imagine bright spots drawn instead of the shadows.
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Re: Which do you prefer? Rembrandt or ALS?

Postby benrob0329 » Fri Apr 15, 2016 5:01 pm

I like the way Rembrandt shadows are cast as well as how Rembrandt water looks.
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Re: Which do you prefer? Rembrandt or ALS?

Postby legoboyvdlp » Thu Apr 21, 2016 3:29 pm

I like the way ALS shadows look and how the ALS water is so beautiful.
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Re: Which do you prefer? Rembrandt or ALS?

Postby DjeL » Sun Apr 24, 2016 1:00 am

I do not understand the big difference between them, but it seems ALS has more quality while Rembrandt runs faster (please correct me if I'm wrong). But, at least on my PC, this doesn't happen, both run at the same frame rate, so I prefer using ALS.
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Re: Which do you prefer? Rembrandt or ALS?

Postby legoboyvdlp » Sun Apr 24, 2016 1:06 am

Rembrandt is slower for most people. It has nicer shadows (unless you avtually make them, there are no shadows in ALS) and lights which work in exterior views (ALS lights only work in interior views). That's pretty much the only good things I can say about it...
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Re: Which do you prefer? Rembrandt or ALS?

Postby DjeL » Sun Apr 24, 2016 1:17 am

legoboyvdlp wrote in Sun Apr 24, 2016 1:06 am:Rembrandt is slower for most people. It has nicer shadows (unless you avtually make them, there are no shadows in ALS) and lights which work in exterior views (ALS lights only work in interior views). That's pretty much the only good things I can say about it...


Well, when I began playing FG, ALS wasn't available yet, so I got used to Rembrandt. Now I upgraded my PC with new graphics, updated to the new 2016 version, started to replace the old SD scenery for the new HD one and also changed to the ALS, to see how it looked like, so I could have get impressed with other features rather than the light scattering and that's why I voted ALS, hahaha :lol:
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Re: Which do you prefer? Rembrandt or ALS?

Postby wkitty42 » Sun Apr 24, 2016 4:33 am

@Djel: the main difference between the two, ALS and Rembrandt, is how they render the scene... one renders "actively" while the other is "deferred"... "deferred" rendering spends time looking at background objects and not rendering them if they are covered by something in the foreground...
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: Which do you prefer? Rembrandt or ALS?

Postby Thorsten » Sun Apr 24, 2016 6:01 am

Let's try for an easy explanation of deferred rendering...

Rembrandt doesn't have to target the screen, it can render things into a 'buffer texture' - so you create an intermediate, abstract picture of the scene, say from a different perspective. Then you can use that buffer texture in the next go where you aim to bring things on-screen. So in this additional 'camera pass' Rembrandt can have an enhanced awareness of how the scene ties together (for instance if you rendered a shadow camera pass first, the final camera pass knows of the results of that first pass).

The advantage of this is that you can render things which don't work in a forward renderer (some reflections, shadow mapping, motion blur...). The disadvantage is that each pass costs processing time - if you have three passes, you'll take (very loosely) three times as long as if you have a single pass.

So deferred rendering gives a different toolbox (it doesn't do anything 'real' either - shadow mapping is just another illusion: semi-transparent objects never cast shadows, billboarded objects cast wrong shadows, secondary lights never create shadows,...). The question is whether that toolbox is worth having the framerate consumption of the additional passes, or whether we do something else with that processing power.

The answer depends on what you want to do.

For rendering daylight visuals from cruise altitude, I can see pretty much no use for the deferred toolbox at all. For rendering a night scene on a busy airport, the deferred toolbox is clearly superior (in an ideal world, we'd be able to switch perhaps... alas, not that easy).

My philosophy has been that I spend the processing power predominantly for what you see most during a typical flight - visuals from pilot perspective are more important than visuals from outside views - I spend 95% of my time from pilot view, visuals from cruise flight like haze, clouds and light are more important than visuals of the terrain close-up, shadows of large objects like clouds are more important than shadows of small objects, ... And frequently for what ALS can't do as well as a deferred renderer, there's often a trick that goes 90% of the way while being reasonably cheap.
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Re: Which do you prefer? Rembrandt or ALS?

Postby wkitty42 » Sun Apr 24, 2016 3:26 pm

when i was looking around to try to get the term "deferred render" i saw an article somewhere that noted that FPS (first person shooters) used deferred rendering for their screens... it kinda makes sense for close-in stuff like that whereas long distance stuff (eg: flying at 5000+ feet AGL) is better done with forward rendering... i never thought about how they did this stuff when carmack released doom way back when... i find it very interesting that he is the CTO of oculus vr now, too ;)
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: Which do you prefer? Rembrandt or ALS?

Postby Thorsten » Sun Apr 24, 2016 6:09 pm

Yes, in an enclosed environment where walls etc frequently block large fractions of the scene, deferred rendering rules performance-wise because the extra passes are all across a tiny subset of the scene - not so for a flightsim.
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Re: Which do you prefer? Rembrandt or ALS?

Postby DjeL » Tue Apr 26, 2016 4:43 am

Ok, now I think I understand. Rembrandt works as a deferred render and ALS as a forward one, right? So, Rembrandt loads more scenery than what I am seeing and when I change my view, the objects will be already loaded onto the system. While ALS only loads the objects I'm looking at, making it use less memory. I just didn't get how this difference can interfere in better or worse performance at night flights. I didn't make the test yet (I don't take night flights often), but it doesn't seem to be big difference on the light system using ALS then when I used Rembrandt.
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Re: Which do you prefer? Rembrandt or ALS?

Postby MIG29pilot » Tue Apr 26, 2016 2:52 pm

Lets put it this way
Rembrandt does this
Image
ALS does this
Image

As far as the end user is concerned, Rembrandt renders the effects of light and shadow, ALS the effects of light and sky.
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Re: Which do you prefer? Rembrandt or ALS?

Postby DjeL » Wed Apr 27, 2016 1:53 am

MIG29pilot wrote in Tue Apr 26, 2016 2:52 pm:
As far as the end user is concerned, Rembrandt renders the effects of light and shadow, ALS the effects of light and sky.


Okay, got it. That is why it is called "ALS", right? Hahaha :P
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Re: Which do you prefer? Rembrandt or ALS?

Postby MIG29pilot » Thu Apr 28, 2016 6:55 pm

ALS= Atmospheric Light Scattering
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