3ds max 5 & brazil test = rendering artefacts?

[Chris Thomas]

Could you give some details? like what version of brazil, the settings you used for key features (ray bounces) and also what features you used during your render...

[treed]

Bene.b, I think your off to a pretty good start. I use Brazil R/S 1.0 and I'm still trying to learn it. Also what version of Brazil are you using because if it took 5 hours that's way to long. I think the free version of brazil is slower than the full copy. :bounce:


treed

[ToddD]

If you guys are using Brazil 1.0, then why not take advantage of the support you get when you buy the registered copy? Bene b it looks like a sampling issue, I don't use brazil that often, but it looks like either sampling or GI samples might be your problem.:thumbsup:

[bene.b]

Thanks for your replies jmonkey2000, treed, and Tbonz816.
As soon as I'm home I'll post details about the render settings. I am experimenting with the Brazil public test version 0.4.53 right now, since I can't afford version 1.0 atm.
I've also read that the public test version is slower than version 1.0, seems to be true because 5 hours is long to render this.
So I'll post the settings in 2 hours, some of them I haven't quite figured out yet (obviously) but I'm working on that :)
cya,
Ben

[acre]

hi, i noe this maybe out of question, but can you kindly tell me where to find tutorials which teaches you how to render realistic glass with brazil?

cheers.

[bene.b]

hi acre,
I found those two tutorials quite useful:
one at 3dkingdom.org (http://www.3dkingdom.org/modules.php?op=modload&name=News&file=article&sid=245&mode=thread&order=0&thold=0)
and the other one
at studiolounge.net (http://studiolounge.net/index.php?name=caustics&left=sub-nav-tutorials)

Concerning the settings of this render:
I have to render it again because since I made this first render I tweaked around and I don't know the exact settings for this pic anymore. :hmm:

cya,
Ben

[Chris Thomas]

I'll hazard a guess at some things that may help

looks like your using secondary illumination by the caustic effects i can see in the image. If you simply use skylight you should get a much faster render.

Brazil 1.0 handles caustics much more effectively using photon maps, these render much more quickly

another thing that could be slowing things down is the number of ray bounces your using. try lowering the refraction and reflection settings. The reflection settings are the most sensitive speed wise, so start out with 1 and do test renders with each increment to see if that helps.

if you can afford it buy 1.0 of brazil, it offers much faster rendering in general compared to the beta (it is a beta, not a demo) and also the full release has many other additions that'll free you up creatively

cheers

[acre]

thanks for the links.

[bene.b]

Wow I was about to post the settings I used for a new pic. jmonkey2000 you know what you are talking about, I'm impressed :)
For the old render I indeed used a light plane to get the caustics on the left side. I thought it should look better than the skylight, but with the light plane the render turns out very pixeled (as you could see in the first render - any idea why?).
It's true that it's not a demo but a beta. I'm sure version 1.0 is well worth it, that's why I'm saving money for it already.

Here is the second render with its settings. It looks much better now, I got rid of the light plane and used only the skylight (no more caustics on the side :thumbsdow), but a reflection on the surface :thumbsup:.
The rendering time increased to 7hrs 30mins which could be attributed to the fact that I used min and max settings of 2 and 4.
I tried increasing by increments as you suggested jmonkey2000. How long should a render like this take on a fairly fast single proc with enought RAM? (does anyone know how much faster brazil 1.0 is compared to the beta?)
http://www.cjvma.org/media/whiskeyglass3_5.jpg
http://www.cjvma.org/media/settings.gif
http://www.cjvma.org/media/settings2.gif

Here are my questions summarized to make it easier:
1. Why is the render so bad when using a light plane?
2. What would be an acceptable rendering time for sth like this?
3. Brazil 1.0 compared to beta: How much faster? (e.g.:50%?)
4. How can I avoid the lines of the rendering box? (e.g. on the bottom right side of the glass)

Thanks for your help guys, it is really important to me, since I need it for a portfolio to apply for a school.

Ben

[bene.b]

hey please don't give up on me!
any got suggestions p l e a s e?

[Chris Thomas]

could you e-mail your glass model to me please, I'll do you a test render then and give you a time :)

Chris Thomas

[bene.b]

k I sent you the the .3ds file.
Do you also need the .max file to get the same materials/settings?
Thanks Chris!

Ben

[Pjanssen]

I'll give you my thoughts on this :
-The sampling seems a little high to me. I often use 0/2 or 1/2 And that gives good results
-Depth of field increases rendertimes, so maybe you could fake that in Photoshop or something like that.
-skylight allso greatly increases rendertimes. So with a good light setup you better get rid of it (allso seen the fact that it isn't an outdoor scene)

edit: Sorry for the DOF :) I thought that you did use it, because the ground was a bit blurry at the first picture.

[bene.b]

Thanks for the tips Pjannsen. I'll try it without the sky light and decrease the sampling.
However, I think :) I didn't use DOF, it's not checked under image sampling!
I'll post sth. if I get better results which are worth mentioning.

Ben

[Chris Thomas]

ok here are some pointers

the AA level can be assumed to be

-1/1 = preview
1/1 = production quality
1/2+ = Very NIIIICE :)

so only use 1/2 for renders that reallyt need it due to sampling issue (moire effects, nasty bump maps etc). You have yours at 2/4 which is pretty much super overkill and very slow

your reflected/refracted rays are at 3/8, these could be quite happily set to 1/4 with little difference, if you notice a big difference in the quality use 2/5

in the luma server, leave skylight on, but don't use indirect illumination, as i said it will give you caustic effects but its a damn slow method and prone to sampling noise.

set the GI shade rate to -3/-2 instead of -3/0. this is adaptive i.e. it will start with a 8x8 pixel sample and work its way down to 1 pixel if it finds the image to be too noisey (the dpative bit...). However for speed its better to use a smaller adaptive range and instead increase the vew rate samples. You have these set at 6 and 3, a produection setting would be more like 20, 15.

hope this helps

here a brazil 1.0 render of your glass, and to show speed/quality i've used some extra features

AA = 1/2
skylight GI @ 15
Caustiics = photon mapped
shadow is from an area light which looks much better than point raytraced shadows with glass

rendertime 20 minutes, dual athlon 1.2ghz


http://www.christopher-thomas.net/glass_example.jpg

[bene.b]

wow Chris thanks a lot for this analysis!
The next thing I'll spend money on will be brazil 1.0 :D
Until then I'll try to get as close to 20 mins as possible :).
Thank you Chris, I owe you sth.! :beer:
Ben

[bene.b]

really great!!!
I just rendered it with AA 1/2, rays 1/4, GI -3/-2 and that's the result:
http://www.cjvma.org/media/whiskeyglass3_5_fast.jpg
in 19mins
vs.
http://www.cjvma.org/media/whiskeyglass3_5.jpg
in 7 hrs 30mins.
I think the result is acceptable considering the MUCH faster render!
:bounce:
I'm so happy thanks guys esp. Chris!

Good night,
Ben

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