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View Full Version : Your Experience with GI noise with Vray?


Francky
06-13-2008, 04:42 PM
Hey Guys, I've had VrayforC4D for a while now. Used it quite a bit on a bunch of projects, but I always seem to be getting a LOT more noise than I used to in 3dsMax. I had asked about this on the Vray forum, but it got nowhere.

Recently I was again confronted with this problem and thought I'd ask here. I know that Vray 1.5 now has an Animation Prepass fonction for GI, but I have to wonder, was this fonction added at the detriment of the quality of GI prior to 1.5 ?

For example, here is a commercial I worked on, a year ago, on 3dsMax with Vray 1.5 rc2 Note that the GI settings where just at Medium Animation...

http://www.bigfuzzydice.com/forum_posts/thumb/BrakeMaster.jpg (http://www.bigfuzzydice.com/forum_posts/BrakeMaster.mov)
(click for animation)

For all intent and purposes, I can not get close to this level of flicker free with VrayForC4d but I have no idea if it's the new Vray 1.5 core that is the culprit (with it's animation prepass feature), VrayForC4D or if the problem is just me and I'm just missing something.

I have to imagine that I'm the problem, lol, since everyone seems so happy with VrayForC4D. Yet I've reinstalled countless times C4D (for different reasons) and I've rendered over network, and all the times, all machines cannot reproduce the result I was getting a year ago in 3dsMax...

Annother basic test I did was to simply create a similar scene with both Max and C4D, both in centimeters and both very basic. Again, I am getting a LOT more noise in C4D.

http://www.bigfuzzydice.com/forum_posts/thumb/HDRI-Test.jpg (http://www.bigfuzzydice.com/forum_posts/GI-Example.mov)
(click for animation)

And the scene is here (http://www.bigfuzzydice.com/forum_posts/GI-Test.zip)

Any of you have experience with the latest Vray 1.5 in 3dsMax ? Is it noisier than before. Or am I missing something basic ?

Thanks,

Francois

Francky
06-14-2008, 05:26 PM
On a side note, perhaps the problem steems from HDR images. As I just did some more test and with normal lighting the problem doesn't seem to be there. (Need to do another compare between soft to be sure)

But my workflow involves using HDR about 99% of the time, so I'm plagued with bad GI because of this problem. I realise that in 3dsMax, Vray has it's own HDR image loader... I wonder if this has something to do with it.

heathivan
06-14-2008, 09:01 PM
subscribing to this thread. :thumbsup:

---h

thev
06-15-2008, 12:20 PM
When using HDR lighting with V-Ray, you would normally use a V-Ray dome light with the HDR texture attached to it, rather than rely just on the GI.

Best regards,
Vlado

Francky
06-15-2008, 09:20 PM
Hi Vlado, thanks for the reply.

I guess that the "global illumination" tab in the render settings is just there for backwards compatibilitie's sake, since the Vray Dome light was added later on?

Did some things change in the new Vray core, meaning that rendering the old way is now noisier and this is the problem I'm seeing ?

But as you may know C4D has no Vray dome light though, so I'm kinda stuck. :(

Thanks

Francois

AAAron
06-16-2008, 04:33 AM
But as you may know C4D has no Vray dome light though, so I'm kinda stuck. :(


The one in the area tab of the vray light tag, is it not the same? It got options for hdri images etc.

lllab
06-16-2008, 09:34 AM
vray has the light dome francky:-)

it was an erro in 1.0876 but worked in older and in newer 1.1.(forthcoming)versions

also download my example in vray forum, there you see how to use hdri with enviroment, also without noise...

cheers
stefan

Francky
06-16-2008, 08:57 PM
Oh thanks for that info Stefan. I'll go take a look at the Vray forum, I must admit I've missed that thread completly. The thread in question, "Dome HDRI Lighting", correct ?

I always loved Vray simple solution, of loading up the image in the render settings, compared to the more involved solution of other soft (like XSI) where you had to create a dome and map the image to it, but in the end I guess we are going back to that workflow.

I have to ask, if doing it the other way, using the GI slot in the environment tab, is not the proper way, and will give bad result, why is it there in the first place in C4D? I understand why in 3dsMax, for backward compability, but for C4D, does it have a purpose ? Just curious :)

Thanks again for the solution Stefan.

Francky
06-16-2008, 09:22 PM
Oops, hadn't seen your post AAAron, You are so right, I was looking for "Dome light" I never thought of looking into the area light tab for it. Makes sense though, as it is a form of area light. Thanks for the info ;)

lllab
06-17-2008, 01:04 PM
vray enviroment has far more detailes controll than vray dome light.
you can also set seperate for reflection, refraction, visibility, etc.

also i get perfect results with it. so it is actually my favorite over the vray dome light. in vray dome light you need lower gi thats right, but i prefer more conrol adn with normal gi you have good hdri light.

in addition it also allows different mapping types and is used for background images...

so a very important feature set:-)

again vray gives you the choice of both...
cheers
stefan

Francky
06-17-2008, 05:01 PM
I can see how the Dome light, combined with an HDR would be the better option, noise wise though. Since it lights without being dependent of GI. One could light a scene without ever turning on GI and still get a very similar look. Hence the cleaner results, no GI noise to begin with, coming from the HDR.

One really has to keep up to date with these darn things, lol. I had been doing it wrong for a long time...

Though, as you mentionned Stefan, it doesn't work right now in 1.0876 (Crashes when HDR is loaded in the dome light) :(

lllab
06-17-2008, 06:07 PM
as said above in 1.0876 the dome is temporarily not working sadly, in 1.1 it is.

still whats the sense of rendering hdri without gi? thats a nice gimmick for me not more.

with gi i get overall better result and more realistic still on all surfaces, also vray is not really slower with gi on. and if you use proper AA settings you get a smooth result in any method, this smoothes out any noise from an hdri, i never have noise that i dont want;-)

i love hdri but mostly use enviroment or even classic light domes (i have my own custom shape domes built in several layers) that i mix with physical sky for very cool results;-)

cheers
stefan

Francky
06-17-2008, 07:14 PM
Obviously, I agree, GI is the way to go, thats the whole point of using Vray ;)

I was just stating what I noticed when using a dome light, like TheV suggested. Cool username by the way Vlado ;)

I liked the fact that one could get a similar look of GI without it, simply for huge projects, where rendering full GI becomes impossible. (Like features and such) It might be a gimmick, but if one is doing cartoon and not photoreal, gimmicky is perfect ;)

lllab
06-18-2008, 09:05 AM
image quality is the point of vray, gi is only a part of that, but not the main secret;-)
so yes of course even without gi you can get very high quality.
i juts prefer to work with gi most time.

cheers
stefan

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