Comments on: Maya Linear Workflow In Two Steps http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/ more serious than before (in a good way) Sat, 04 Sep 2010 01:29:07 +1000 http://wordpress.org/?v=2.9.2 hourly 1 By: david http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10511 david Sat, 17 Jul 2010 03:58:27 +0000 http://www.djx.com.au/blog/?p=289#comment-10511 n8skow, my post is about the basic steps required to get a linear result from your render. To do that you need to set gain=1. Your render appears blown out when you use physical_sun_sky because of the huge dynamic range that this illumination system uses. If you render to float exr (recommended) then you can adjust the exposure in post and bring those over-brights back into a viewable range. The idea of using linear workflow is that you keep things linear for you render, and for some of your compositing. At some point, if you are going to output those images in an 8 bit format (tv broadcast for example) then you need to do exposure and tone mapping adjustments. There is nothing wrong with making those adjustments in the mia_exposure node if that is how you want to do it, but you need to understand that the images that you get will no longer be linear. n8skow, my post is about the basic steps required to get a linear result from your render. To do that you need to set gain=1.

Your render appears blown out when you use physical_sun_sky because of the huge dynamic range that this illumination system uses. If you render to float exr (recommended) then you can adjust the exposure in post and bring those over-brights back into a viewable range. The idea of using linear workflow is that you keep things linear for you render, and for some of your compositing. At some point, if you are going to output those images in an 8 bit format (tv broadcast for example) then you need to do exposure and tone mapping adjustments.

There is nothing wrong with making those adjustments in the mia_exposure node if that is how you want to do it, but you need to understand that the images that you get will no longer be linear.

]]> By: n8skow http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10510 n8skow Thu, 15 Jul 2010 16:21:39 +0000 http://www.djx.com.au/blog/?p=289#comment-10510 Hey David. I'm curious how you arrived at your final value of "1" for your Gain setting... Using 1 gives me a completely blown out (white) sky when using physical_sun_sky. thanks man Hey David.

I'm curious how you arrived at your final value of "1" for your Gain setting...
Using 1 gives me a completely blown out (white) sky when using physical_sun_sky.

thanks man

]]> By: david http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10504 david Fri, 11 Jun 2010 10:44:10 +0000 http://www.djx.com.au/blog/?p=289#comment-10504 Say you will be compositing in Nuke, then you would render to a float format, like openEXR. To continue your linear workflow you need to remove the gamma from the lens shader so that the rendered images are still linear. The idea is that you only add the gamma=2.2 at the end of all processing, which includes most things you would do in Nuke. And to correct your terminology slightly, the lens shader does not return any lost detail since nothing gets lost, it adds a gamma correction curve so that the image looks right on an sRGB monitor. If you render to float, all the details are preserved. Say you will be compositing in Nuke, then you would render to a float format, like openEXR. To continue your linear workflow you need to remove the gamma from the lens shader so that the rendered images are still linear. The idea is that you only add the gamma=2.2 at the end of all processing, which includes most things you would do in Nuke.

And to correct your terminology slightly, the lens shader does not return any lost detail since nothing gets lost, it adds a gamma correction curve so that the image looks right on an sRGB monitor. If you render to float, all the details are preserved.

]]> By: AlexMGD http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10503 AlexMGD Fri, 11 Jun 2010 03:44:09 +0000 http://www.djx.com.au/blog/?p=289#comment-10503 oh sorry David I didn't realize you meant 32 bit images for textures! now I understand that. Im still confused about disconnecting the lense shader when batch rendering oh sorry David I didn't realize you meant 32 bit images for textures! now I understand that.
Im still confused about disconnecting the lense shader when batch rendering

]]> By: AlexMGD http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10502 AlexMGD Fri, 11 Jun 2010 03:11:03 +0000 http://www.djx.com.au/blog/?p=289#comment-10502 Daivid, I am so confused about this process .. I have a couple of questions regarding your 2-step workflow You say that if I want to take the rendersand process them further in compositing, I should disconnect the lens shader. Why is that? isn't it the point fo the lens shader to bring up the lost detail and lighting back to the image? Also, you say that for floating point (32bpc) images I am not supposed to add the gamma node of 0.455 to the textures.. Does this mean that if I want to batch render a sequence of floating point images I shouldn't add gamma nodes and I shouldnt add lens shader? I should just work as if this workflow doesnt' exist? please enlighten me if you care to! thanks Daivid, I am so confused about this process .. I have a couple of questions regarding your 2-step workflow
You say that if I want to take the rendersand process them further in compositing, I should disconnect the lens shader. Why is that? isn't it the point fo the lens shader to bring up the lost detail and lighting back to the image?
Also, you say that for floating point (32bpc) images I am not supposed to add the gamma node of 0.455 to the textures.. Does this mean that if I want to batch render a sequence of floating point images I shouldn't add gamma nodes and I shouldnt add lens shader? I should just work as if this workflow doesnt' exist?
please enlighten me if you care to!
thanks

]]> By: rasto http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10479 rasto Wed, 31 Mar 2010 19:03:26 +0000 http://www.djx.com.au/blog/?p=289#comment-10479 Support for color profiles in Maya 2011 - http://download.autodesk.com/us/maya/2011help/movies/Color_Profile.html http://www.toxik.sk - Maya 2011 Screenshots + Videos Support for color profiles in Maya 2011 - http://download.autodesk.com/us/maya/2011help/movies/Color_Profile.html

http://www.toxik.sk - Maya 2011 Screenshots + Videos

]]> By: smokedogg http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10476 smokedogg Wed, 17 Mar 2010 20:04:25 +0000 http://www.djx.com.au/blog/?p=289#comment-10476 Yeah, well I will just wait to see that happen. I thought that has been mentioned a ton of times saying that Maya will soon implement linear workflow. I really hope so... Yeah, well I will just wait to see that happen. I thought that has been mentioned a ton of times saying that Maya will soon implement linear workflow. I really hope so...

]]> By: david http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10475 david Fri, 12 Mar 2010 11:11:39 +0000 http://www.djx.com.au/blog/?p=289#comment-10475 Thanks for the kind words smokedogg. I've just been reading about the soon to be released maya 2011 and it seems that linear workflow is going to be a whole lot easier. Finally. Thanks for the kind words smokedogg.

I've just been reading about the soon to be released maya 2011 and it seems that linear workflow is going to be a whole lot easier. Finally.

]]> By: smokedogg http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10474 smokedogg Fri, 12 Mar 2010 06:00:27 +0000 http://www.djx.com.au/blog/?p=289#comment-10474 David, very simple, very clear, and very understandable explanation of linear workflow. Well done! David, very simple, very clear, and very understandable explanation of linear workflow. Well done!

]]> By: david http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/comment-page-1/#comment-10473 david Mon, 08 Mar 2010 05:59:07 +0000 http://www.djx.com.au/blog/?p=289#comment-10473 medooch, speculation is not really my thing. I attribute the messy mentalray integration to a lack of priority and misguided attempt to maintain full backward compatibility for the sake of old scenes. There are some scripts here http://3dlight.blogspot.com/2008/09/gamma-tools-10.html that you can use to insert gamma nodes, but I've yet to see something that would be considered fully automated. Kieman, that "Linear Workflow" box has me confused. The manual states "Note that this option is intended to be used only for quickly converting old scenes which are not set up with proper linear workflow in mind. This option is not a replacement for proper linear workflow." I will be spending more time learning vray in the near future, but if you care to elaborate on this it would be great. medooch, speculation is not really my thing. I attribute the messy mentalray integration to a lack of priority and misguided attempt to maintain full backward compatibility for the sake of old scenes.

There are some scripts here http://3dlight.blogspot.com/2008/09/gamma-tools-10.html that you can use to insert gamma nodes, but I've yet to see something that would be considered fully automated.

Kieman, that "Linear Workflow" box has me confused. The manual states "Note that this option is intended to be used only for quickly converting old scenes which are not set up with proper linear workflow in mind. This option is not a replacement for proper linear workflow."
I will be spending more time learning vray in the near future, but if you care to elaborate on this it would be great.

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