Author Topic: VRay vs Corona (yes, again) - SCENE INCLUDED  (Read 21515 times)

2015-05-20, 16:26:00
Reply #15

cecofuli

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DeadClown, this thread is just for fun.
I don' t want to say "VRay is best, Corona is the best etc...".
Just share some experiences.
We know that Corona has no adaptivity.
So, with the actual version of corona, I would liked to see what we can do.
for example, Rawalanche suggestion is a good idea (Bucket mode) =)

2015-05-20, 16:28:50
Reply #16

Ludvik Koutny

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FFFFFFFUUUUU, sorry. This is because I don't have Vray and the camera loaded upside-down, I had to create a new on in the same place and rotate it. Could some good soul re-save the scene with a standard camera?

In my scene (attached under my post), i replaced the Vray camera with native one, so grab it :)

2015-05-20, 16:40:42
Reply #17

maru

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And btw, using defaults are useful for a settings-limited renderer like corona but you cannot expect anyone to use vray defaults (for reasons vray users know).
My point was, that if you devoted some time to find optimal settings in vray, then why not do the same with corona instead of using defaults?

2015-05-20, 16:40:55
Reply #18

Ludvik Koutny

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Maybe there is slightly more noise than before so it would require a bit more GI samples, but a jump from 7 to 4,5min is pretty big, right? If you are using adaptive supersampling in V-ray (2-64), then why set it in Corona to 110 passes? Also, I guess you didn't use default settings in Vray, and you used defaults in Corona - this is a bit unfair. I was kidding about the fanboyism in the first post, but please correct me if I'm making some stupid mistakes here.

Sorry to say that but this is exactly why those threads always become useless after a short while.
If you'd really want to compare Vrays 64 max to corona you'd have to increase corona passes to 4096 - vray's is subdivision, thus 62^2  = 4096 passes (reachable maximum). So much for fair comparison. Vray's strength is adaptivity, and none of the "possible" improvements posted here to make corona faster are actually making any sense if you want to compare it 1:1 (whatever this should be).
If you really want to make corona so much faster, decrease the albedo to a bare minimum and crank up the exposure, wouldn't make the discussion much worse...
And btw, using defaults are useful for a settings-limited renderer like corona but you cannot expect anyone to use vray defaults (for reasons vray users know).

I don't think these threads always need to turn into pissing contests unless someone starts to directly imply they should :)

They can remain objective as long as the mistakes in testing methodology are not made.

So first of all, we are not comparing renderers at identical settings, but we are comparing visual quality at a given rendertime. If there was 40 or 4000 AA rays shot does not matter as long as both pictures look visually good, meaning there are no obvious differences in quality. Nice example of quality difference is absence of reflective caustics in Cecofuli's first render. That's kind of aspect that should not be left out, but AA sampling is the opposite.

And sure vray can eventually cast all 4096 rays per pixel, but it rarely does. I actually have exterior scene with car here at work, which has coincidentally 64 subdivs as max value, and you would not believe how long can one bucket, even as small as 16*16px take, when it stumbles upon direct sunlight reflection. Even 10 minutes when it comes to it. So when Vray finally reaches some area that needs those 4096 rays, it will take quite long to crunch it.

What point would be comparing identical render settings of renderers that do not have identical settings? That would not be senseful comparison at all. Senseful comparison in this case can only be comparing visual quality at fixed time, or comparing time it takes to reach similar visual quality. Not comparing how many rays each of the renderers shot, because this is attribute that does not have direct effect at quality of the output. What good is it if Vray wasted hundreds of AA samples somewhere in the scene when perceptual AA quality ends up indistinguishable from Corona output that used only dozens of AA rays?

2015-05-20, 16:54:53
Reply #19

DeadClown

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Well, I didn't want to be the party pooper here, so sorry if that was the case. I simply forget every time that I should probably keep out of discussions like that. My problem was that I had the impression that everyone tried to get an image matching the vray one as close as possible (better speed, less noise) when it would actually be a lot easier to render a corona image with "best possible settings" and let someone do a highly optimized vray version. You could easily squeeze some minutes out of the vray one (still using Bf etc)

But as I said, I should keep myself out of those things ;)
Any sufficiently advanced bug is indistinguishable from a feature.

2015-05-20, 17:04:06
Reply #20

Ludvik Koutny

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Well, now there is a version of this scene in Corona, that seems to be pretty much 50:50 with Vray. Little more noise here, little less noise there. I don't think i could optimize it significantly more, so now it's possible to start squeezing some minutes out of the Vray one :) But of course only of quality remains on par with corona (no reflective caustics disabling, etc...) :)

2015-05-20, 17:33:06
Reply #21

cecofuli

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Ok, I was able to have the same rendering time 11min 40 sec in Corona, in Bucket mode (16, 16 0.03)
Nothing changed. In Corona everything is as before: I have a plane outside and the glasses have caustics ON.
VRay has less noise and the differences, in Corona, bethween progressive and bucket isn't so big.
Now, the shadows under the torus are black, and not green, like in VRay.

PS: I think, if we reduce MSI from 20 to 10, I'm able to remove a little bit of noise, as Rawalanche did.

« Last Edit: 2015-05-20, 17:44:22 by cecofuli »

2015-05-20, 18:55:51
Reply #22

maru

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Ok, my last try. The original file by Rawalanche (07:17) vs buckets (05:34).

2015-05-20, 19:17:09
Reply #23

Alex Abarca

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What is the conclusion, Is corona really faster than VRAY?

2015-05-20, 20:23:11
Reply #24

lacilaci

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"PS: I think, if we reduce MSI from 20 to 10, I'm able to remove a little bit of noise, as Rawalanche did" = aaaand you also cut off quite a bit of GI from the sun...

2015-05-20, 20:57:16
Reply #25

Ludvik Koutny

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Ok, my last try. The original file by Rawalanche (07:17) vs buckets (05:34).

Afaik my file had buckets set up too :)

2015-05-20, 21:00:02
Reply #26

Ludvik Koutny

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What is the conclusion, Is corona really faster than VRAY?

Conclusion is that renderer code is only about 60% of the average renderer speed factor, remaining 40% of the factor are skill of the user using it. So Vray used by skilled user can be a lot faster than Corona used by unskilled one, and vice-versa :)

2015-05-20, 21:47:59
Reply #27

cecofuli

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In my opinion, if you use VRay in IM+LC, yes (obviously)
if you use QMC+LC, it depends.
In this simple example my answer is YES. But, as I wrote, it's simple.
It's easy to tweak one light and two shaders to obtain the best rendering time and less noise as possible.
For this scene, I did many tests to get the best ratio between anti-aliasing, subdivision, noise. I needed to look at render elements to understand better the noise etc...
But, if you have complex scene, with +50 shaders, +30 lights, you have to spend hours to understand why you had some noise in some areas, or why a single bucket stays 10 minutes in the same place, etc...
With Corona, you hadn't do that, never. Just work, click render and you are 99% sure about the final result.
I prefer to work to create a new location, instead t se correctly a renderer, by doing 30 test-render
And, often, it's faster than V-Ray (often because, at the end, you are tired to make 20 render test or you don't understand well how to solve some trouble).

2015-05-20, 22:22:33
Reply #28

pokoy

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In my eyes, a comparison like this misses the point. Are we going to applaud a 10 seconds render that lacks everything that makes it visually pleasant? The quality differences here are quite noticeable and range from subtle shades in the shadows to quite big differences in reflections and refractions, the result from Corona is just more pleasant even in a simple example like this.
I would grant Corona 5 minutes more solely for the fact that it will have more 'depth'. Since these things are so subtle they can't really be expressed in numbers and render times...
For me it's something else that's impressive here: to see how much adaptive sampling can help to get rid of noise. Then again, a real-world camera will almost always show more noise.
« Last Edit: 2015-05-20, 22:41:58 by pokoy »

2015-05-20, 22:33:25
Reply #29

cecofuli

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I agree with you pokoy: adaptive sampling  is very important!
In addition, each one will read this test as he wants.
There are users who want as little noise as possible, others users need "deeper" rendering, even with some noise.
There are those who, instead, needs a quick setup without too much trouble, regardless of noise and depth.