Arnold Q&A

Discussions about rendering in SOFTIMAGE©
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xsisupport
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Re: Arnold Q&A

Post by xsisupport » 23 Jan 2014, 16:18

sant0s wrote:hey,
just tried to test render on rebus farm - but it always gives error message that the path to images is wrong and stops rendering.
so I guess, I have to check/uncheck something and maybe change the environment for textures?
It's probably the Textures Search Path in the Renderer options.
I don't know how Rebus Farm works, and a quick scan of their web site didn't tell me how it handles texture paths.
// Steve Blair
// "You're not a runner, you're just a guy who runs" -- my wife
//
// My Blogs: Arnold | Softimage

hamed19
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Re: Arnold Q&A

Post by hamed19 » 23 Jan 2014, 17:18

How to render the flame,fire,dust, smoke and like them with Arnold?








-------------------------------
Sorry for my poor English.

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sant0s
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Re: Arnold Q&A

Post by sant0s » 24 Jan 2014, 10:55


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Re: Arnold Q&A

Post by sant0s » 30 Jan 2014, 20:08

is there a way, to color strands in arnold like in this video?







i heard, its only possible with a custom shader?

scaron
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Re: Arnold Q&A

Post by scaron » 07 Feb 2014, 02:43

sant0s wrote:is there a way, to color strands in arnold like in this video?
i heard, its only possible with a custom shader?
you mean the shading along the strand?

yes, use a gradient and use scalar state set to lengthwise hair to drive the gradient

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sant0s
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Re: Arnold Q&A

Post by sant0s » 08 Feb 2014, 02:00

thats actually what im need, thx.
only problem is, that the gradient gets streched as longer the strand gets - so i guess, i need to get some more data from the strand to feed into the shader?
is it possible to calculate a fixed part on the strand and input that to the gradient?

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rray
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Re: Arnold Q&A

Post by rray » 08 Feb 2014, 10:47

Can't speak for arnold but in mental ray you could write each strand's length into an attribute, read that attribute from the render tree using the scalar attribute node, and convert that value some way into gradient colors positions so that the absolute length of the tip part remains constant for example.

If Solidangle did a 1:1 conversion of the gradient node that should work there too.
softimage resources section updated Jan 5th 2024

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sant0s
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Re: Arnold Q&A

Post by sant0s » 08 Feb 2014, 12:01

Getting closer, thx alot! :)

Its working for Strand Trails already. Using Scalar Attribute and set it to StrandAge, Value to 1 and input that into the gradient.
For Strands itself i'll have to figure out how that works - seems to be bit more than just to nodes.
Do you mean each strand segments length? Because strand length is already in the list.
Will try that later - but I think I just have to divide the strand length through segment count to get segments length ;)

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Re: Arnold Q&A

Post by rray » 08 Feb 2014, 13:45

I would use total strand length, in case the segments have different lengths. There are compounds out there that calculate ther total strand length (kristinka/melena?)
It would require a relation higher strandlength ==> lower value for the gradient node so it must be an inverse relation of some kind for example 1/strandLength times some factor
softimage resources section updated Jan 5th 2024

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sant0s
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Re: Arnold Q&A

Post by sant0s » 08 Feb 2014, 14:17

ah okay, I had a wrong understanding of segments - thought they keep same length they get emitted :)
will try that out.

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diissar
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Re: Arnold Q&A

Post by diissar » 09 Feb 2014, 22:31

hello,Im a little bit confused about linear workflow settings,can anyone help?
Im using Softimage 2014SP2.

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xsisupport
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Re: Arnold Q&A

Post by xsisupport » 10 Feb 2014, 12:11

diissar wrote:hello,Im a little bit confused about linear workflow settings,can anyone help?
Im using Softimage 2014SP2.
Output gamma is the gamma correction applied to the render region, and to non-floating point render output.
Shader/light/texture gamma are for linearizingthe input data.

You could set all the Arnold gamma settings to 1, and use the Softimage color management settings (some people leave the Arnold Texture gamma at 2.2, to linearize 8- and 16-bit non-floating point textures).
// Steve Blair
// "You're not a runner, you're just a guy who runs" -- my wife
//
// My Blogs: Arnold | Softimage

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diissar
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Re: Arnold Q&A

Post by diissar » 10 Feb 2014, 12:45

xsisupport wrote:
diissar wrote:hello,Im a little bit confused about linear workflow settings,can anyone help?
Im using Softimage 2014SP2.
Output gamma is the gamma correction applied to the render region, and to non-floating point render output.
Shader/light/texture gamma are for linearizingthe input data.

You could set all the Arnold gamma settings to 1, and use the Softimage color management settings (some people leave the Arnold Texture gamma at 2.2, to linearize 8- and 16-bit non-floating point textures).
OK,I think I got it,Thank you !

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sant0s
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Re: Arnold Q&A

Post by sant0s » 26 Feb 2014, 20:44

was triying to build something like a street shader and got a result that is fine for what I need it.
I also tried to get it to run under arnold, but as you can see on the image, there is that falloff.

any idea how to fix that? I have noticed that in the ppg of the gradient, right at the border where white and black meet, the slider has a little fallof, too.
the gradient itself has that problem - its not that I plugged something wrong. :)
Attachments
arnold_street.jpg
strassen_shader.jpg

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cheeseburger
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Re: Arnold Q&A

Post by cheeseburger » 01 Mar 2014, 01:37

I couldn't see any documentation on how to get fog/atmosphere (I think it's called volume scattering). Is it possible in an easy way ?

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sant0s
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Re: Arnold Q&A

Post by sant0s » 01 Mar 2014, 09:48

you have a fog shader thats actually quite easy to setup.
in xsi just go to arnold/shaders/fog - guess maya is similar.

for volume scattering you add the shader and specify a light to scatter.

here https://support.solidangle.com/display/ ... Scattering
and
here https://support.solidangle.com/display/SItoAUG/Fog

are the most importent infos.

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