Comments on: Compositing Maya 2009 Render Passes with After Effects

By: John

John — Wed, 18 Nov 2009 04:46:11 +0000

From the Maya 2010 docs:
Colorclip

Controls how colors are clipped into a valid range [0, 1] before being written to a non-floating point frame buffer or file.

In all modes, the RGB components are clipped as specified by the desaturate option. The RGB and alpha modes ensure that the resulting color is a valid premultiplied color.

Clipping occurs only in 8-bit integer and 16-bit integer frame buffers. if you are using float and half-float, no clipping occurs.

RGB

RGB is first clipped to [0, 1] and alpha subsequently to [max(R, G, B), 1]. Use RGB if the alpha channel is considered less important than preserving the RGB color and intensity.
Alpha

Alpha is first clipped to [0, 1] and RGB subsequently to [0, A]. Alpha mode is intended for alpha compositing, where the alpha channel is more important than the absolute color value to preserve correct transparencies.
Raw (default)

RGB and A are both clipped to [0, 1] independently of each other. Use Raw mode only if no layering based on alpha is going to take place. This mode turns Premultiply on, so use it with care because shaders might receive colors that cannot be composited in standard ways.

By: ramses objio

ramses objio — Wed, 16 Sep 2009 06:15:54 +0000

for the render pass depthRemapped and depth in mental ray EXR 32 bits work great because it seems to be working in the original maya units i was working in respect to distance, if you see a black image for depth pass then you need to clamp to to find the correct values, to do this add the extractor then a levels, change the extractor values to depth and then look for the black point and white point range close to those you use in maya clip planes then you will be able to see in the levels historigram effect the values appear, then just clamp the values to the desire range using levels. hope this helps, this tut just made my life so easier because i had so much problems with this subject in the past THANKS

By: Jake

Jake — Thu, 20 Aug 2009 17:15:20 +0000

This was happening to me with the extractor plugin that shipped with after effects. I put the new one in
applications > after effects > plug-ins > effects
replacing the old version, and then it worked after that. Hope this helps!

By: Gary

Gary — Thu, 20 Aug 2009 08:08:16 +0000

Hi,

My AE CS3 keeps crashing when I try to import the exr sequence. Does anyone know why this happens? I tried downloading the plug ins from the proexr website and placing them in the respective folders. I have a MAC. The website doesn’t do a good job explaining where to place the replacement plug ins.

Has anyone needed to troubleshoot this?

By: Jason Brummett

Jason Brummett — Sun, 19 Apr 2009 05:40:37 +0000

Jake,

Just upgrading to Maya 2009 and therefor SPa1 too. So I don’t have much testing time at this point but seeing the issues here but thought I’d throw out that under the MR Globals>Quality Settings>Framebuffer>Color Clip…

Maya is set to RAW unlike RGB modes will clamp 0-1 color space and affect premultiplication of rendered images. I’m guessing this could end in a result where a clamped render might get close to a Beauty render or be way off based on the particular scene. Wondered if you’d investigated this yet with the new renderer? Don’t have time myself but if I get to it will post my results then.

Thanks for your help on this topic!

Jason

By: Darren

Darren — Mon, 16 Feb 2009 03:02:50 +0000

I see, it uses maya software renderer. I can’t believe I forgot the use background shader. I’d stopped using it in past versions because it had some quirks with MR. Going to give it a whirl though. I used to use that to grab shadow and spec.

thanks for the help

By: Jake

Jake — Sun, 15 Feb 2009 06:08:54 +0000

the old method of “render layer shadow” is that there used to be a render layer preset for shadow renders. now it is disabled and replaced with broken render passes, but it still exists in the application if you use mel:
creating a new render layer and then:
renderLayerBuiltinPreset shadow Render_Layer_Name;

As for your workaround- there are various things you can do if you want to set it up manually. white would work okay but you might also experiment with a “use background” shader to receive the shadows in a way that involved an alpha.
Here’s a third way: http://www.3drender.com/light/shadpass.htm

By: Darren

Darren — Sun, 15 Feb 2009 05:31:40 +0000

Well, you don’t see the particles, basically our poly geo is taking the place of particles using maya’s instancer. But shadows do show up on the geometry in beauty passes. All the other MR shaders work, and we are using mia_material_x_passes for our geo, btw.

By the old way do you mean just ticking off that box in the render layer attributes? That doesn’t always work either

The only workaround I could think of was maybe creating a white shader and adding that to the objects, shutting off FG, render that and and multiply it in post.

By: Jake

Jake — Sun, 15 Feb 2009 05:25:34 +0000

Does the particle shadow show properly on a composite render?
I would suggest not trying to use a render pass for the shadows (ever- in maya 2009 since it’s so broken) you set up a separate render layer and there you should set up a shadow render according to the method used in versions previous to maya 2009. Autodesk support can walk you through the old method if you aren’t familiar. I have not experimented with instanced nParticles, so I can’t offer a workaround if there is a bug there.
Hope this helps! Good luck.

By: Darren

Darren — Sun, 15 Feb 2009 05:01:58 +0000

I cannot manage to get a shadow pass out of my scene that has objects instanced to nParticle systems.

Many of the Illumination passes get through and are saved out in a single EXR file, and in a test scene I made did get a raw shadow in an EXR when using depth map shadows, however the channels were all mixed up. In my production scene though, no matter how I try to setup the lights or optimize the scene, I cannot for the life of me, get out a shadow pass.

This behavior is happening on both Mac OS X and windows XP Pro x64 versions of Maya 2009.

Any info will be appreciated because in this particular shot we need to have an additional shadow pass and after 3 days of poking and prodding at maya’s settings we have gotten nowhere.

Thanks