Introduction to Maya - Rendering in Arnold
This course will look at the fundamentals of rendering in Arnold. We'll go through the different light types available, cameras, shaders, Arnold's render settings and finally how to split an image into render passes (AOV's), before we then reassemble it i
# 16 09-10-2008 , 09:28 AM
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That's much more like it, still need work though:
user added imageuser added image
I'm done for today.

Does someone know what I need to do to get rid of these specific(grain(or whatever it's called) like) artifacts? I raised the overall quality an it's better then it was before but I don't want to raise anything that I don't need. render time is already 5:30 for this one(and a half) figure(s)...
Thanks,
Benny


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My latest snake game
(Requires DirectX9 SDK and Framework)

Last edited by BennyK; 09-10-2008 at 09:31 AM.
# 17 09-10-2008 , 09:40 AM
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Yeah now that I see your ref, the super mega blurry refractions would look best. And your samples are too low hence the grain. What material are you using?


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# 18 09-10-2008 , 11:23 AM
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Thanks, I'll have a look there.
Here are the materials:
murky glass| clear glass
user added image
(did I mention I love SnagIt?)
Benny
EDIT: raising anti aliasing sampling worked. Thanks again :bow:


When in doubt, delete history and freeze transformations.

My latest snake game
(Requires DirectX9 SDK and Framework)

Last edited by BennyK; 09-10-2008 at 11:29 AM.
# 19 09-10-2008 , 05:16 PM
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Lol yeah SnagIt makes things soooo much easier and more fun. And raising anti aliasing helps with grain but theres an attribute on the shaders to help eliminate that, kinda like the relationship between light radius and shadow rays.

user added image


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# 20 09-10-2008 , 07:07 PM
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Thanks, I'll look at that as well in the next render - I need to use the 16 to 256 currently to eliminate it completely and it take way too much time to render a 320X480 with it, and I really don't want to find out how long it takes to render a 1600X1200 with it user added image

Here's what I've(my computer have) done overnight:
user added image

Added irradiance and scattering and it addes exactly the feeling I was looking for, even though I don't really know what these attributes do user added image ...

I'll try to improve the clear glass shader before I go on because it looks a bit disappointing...

Holiday over so I don't know when the next post (that is containing progress) will be user added image
C&C please,
Benny


When in doubt, delete history and freeze transformations.

My latest snake game
(Requires DirectX9 SDK and Framework)

Last edited by BennyK; 09-10-2008 at 07:20 PM.
# 21 10-10-2008 , 01:39 AM
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Its coming along. Though I think the lighting needs tweaking as its really burning out the details on the pieces, you really see it around the bases.


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# 22 10-10-2008 , 02:28 AM
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Its looking good but imo the pieces aren't looking like they are from the same box.

# 23 10-10-2008 , 05:25 AM
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Thanks :attn:
I'll see what I can do about the lights.

Here's another render after adding Fresnel effect and chrome for the clear glass:
user added imageuser added image
2h 8m already user added image
:headbang: :headbang: :headbang: :headbang:

hammer.horror: do they? what's imo btw?

And I have a little question: how can I create something like what I get with bookmarks for cameras for the render settings? I tried presets but it doesn't work right user added image
Thanks in advance,
Benny


When in doubt, delete history and freeze transformations.

My latest snake game
(Requires DirectX9 SDK and Framework)
# 24 10-10-2008 , 05:39 AM
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The presets don't work right, how so? I've never had a problem with it. 2h 8m is a lot for this but then again I don't know your specs. Most likely you jacked up a setting way higher than need be.


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# 25 10-10-2008 , 09:29 AM
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Nvm the presets, they work now... I don't know why I had problems with them.
Here are my specs:
Intel Pentium 4 Prescott (800kb cash) 2.6GHz
1 GB RAM DDR 400MHz
ATI Radeon 9550 256MB (AGP 8X)
Windows XP sp2

Don't know what else could be relevant...

Here are my render settings for the 2h 8m render:
user added image

Anything you think I need to lower/raise or turn on/of etc. to improve the quality/performance ratio?
I've also got two more questions about MR:
*What does 'Acceleration' under Raytracing do?
*What does the primary framebuffer do? Especially 'Data type'.

Here's a test render with low quality that took 16m:
user added imageuser added image
presets make life much easier user added image

Benny


When in doubt, delete history and freeze transformations.

My latest snake game
(Requires DirectX9 SDK and Framework)
# 26 10-10-2008 , 10:47 AM
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framebuffers deals with the type of data your writing out of mental ray. For example if you want to write out to a larger bit depth like with .exr format you would want to set it to rgba_fp (floating point) or rgba_h (16 bit) data type.

exr format is a fantastic . Maya 2009 will come with much better support for this format, i suggest it becomes everyones default if your not using it allready.
Read up on it especially if your into compositing.

If you just want to do standard rendering you really dont have to worry too much.

acceleration is just how mental ray will deal with the scene at render time. Read about it in the help files its all there, i allways tend to callibrate my bsp properly if im doing ray tracing. There is a diagnose tab in mental ray where you can see the results of your bsp settings visually, very usefull.

Your renders look ok, I really think you need an enviroment to refract and reflect a bit, clear glass will get all its surface shading values from reflection and refraction, so its important to have somthing there to get a convincing result.

Oh and on render settings, set your max sample level to 2 for production, you need to be rendering at super high res to warrent any higher. If your just testing turn it to 0.

Under raytracing remember that your reflectoin and refraction number setting referes to the number of bounces in the scene not the quality of the raytrace itself. When you have reflections and refractions set to 10, mental ray will refract/ reflect 10 times before returning a sample value. think about how many times it will need to refract or reflect. Start at low 2 maybe 3 and then work up only if you need to.

When it come to blurring reflections and refractoins, i would do that in post if possible, render out refractions and reflections sperately and then blur them. You will need an ID pass as well to have correct matts for each object.

# 27 10-10-2008 , 11:30 AM
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Thanks (again) for the reply :bow:
I'll do some testing for reflection/refraction amount now. This scene contains enough reflections and refractions for a super computer to calculate for a few weeks so I thought It needs to be high. I don't know why I haven't thought about checking what actually helps...

About the max sampling - for a value of 2 I get the result I got in the first post of this page(2). Genny's advise about reflection and refraction rays didn't help much.

just a few more questions:
*Since I've never touched BSP I don't really know how to optimize it. What settings do you recommend I use for a scene like this? 'large scenes' in Maya help isn't really specific...
*What exactly is exr? I found all sort's of mixed up stuff in Google, not much help... was also mentioned a few times in Maya help together with OpenEXR which probably isn't it...
Anyway, What's exr?

Thanks in advance,
Benny


When in doubt, delete history and freeze transformations.

My latest snake game
(Requires DirectX9 SDK and Framework)
# 28 10-10-2008 , 11:50 AM
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exr is a 32 bit format developed by ilm ages ago, its industry standard as it has the most detail in it compared to other floating point formats like log luv.

The difference between luminance the eye can detect is around 4%. If the value step is greater than this you start to get banding and ugly format problems, most hdri formats have around 2-3% difference, but exr can hold 1% which is good for cgi as it can hold up well to lots of blending, layering and manipulation.

Exr doesnt have as high a dynamic range as other formats but its plenty for cgi. The best thing about exr is that it can hold hold multiple passes like occlusion, UV, world space normals, z depth, reflections, refractions, shadows, ID whatever you want. So its really good for compositing, unfortunately maya 2008 doesnt support that functionality of the exr format, im sure you can do it with mental ray but its too much to be bothered with, so i usually just output all my auxillary information as seperate sequences.

The artifacting your getting looks like its due to your refractions being undersampled, i would really just do those blurs in post. Its a bit like motion blur, it looks nice as its truely 3D in mental ray but it really isnt worth the render time. Render out a reflection and refraction pass, and an ID pass then you can blur and tweak in post.

With your bsp, for a scene like this i would jsut use defaults, its not a heavy scene, its important if you have busy scenes as there is a chance of maya crashing if it tries do deal with too much at onces. For example if it tries to render an area at once which has hundreds of polygons and textures in.

Do you have any compositing experience? Or have any compositing packages, if your on mac buy shake, its cheap now, or if your on PC AE is the affordable option.

If your rich, i would go for nuke or digital fusion are great out the box.

# 29 10-10-2008 , 01:40 PM
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Benny even messing with BSP settings a teeny tiny bit can shoot the render time all to hell if you don't have proper settings. And for this scene you don't need to touch it, first thing I noticed was the really high AA settings.. The refraction rays do influence the grain in the refraction blur, turn down your AA settings and try again.


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# 30 10-10-2008 , 07:54 PM
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So basically I need to use a half or a floating point framebuffer format, lower anti aliasing samples, increase refraction rays, lower refraction and reflection limits and not touch the BSP. Simple enough, Thanks user added image

Sorry for the late response ( :zzz: ) .
Here's a render I left overnight :
user added imageuser added image
2h 18m for this one.
that's weird, since it's a much more dance scene and I've added 4 spotlights (instead of the directional I had) and a HDRI (last HDRI was in a slightly different version).

I'll work on some of the above now...
C&C please
Benny

EDIT: almost forgot, I've got no compositing experience and everything I now about post is what I can do in Photoshop if it counts... LOL


When in doubt, delete history and freeze transformations.

My latest snake game
(Requires DirectX9 SDK and Framework)

Last edited by BennyK; 10-10-2008 at 08:05 PM.
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