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# 1 19-04-2012 , 07:18 PM
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Adding displacement map breaks render

Hi All.
So basically I plug in a displacement map into a shader, assign to object and when I go to render in mental ray production quality preset settings it begins the render process but then stops within a couple of seconds and says render complete without actually having done anything apart from creating a 1kb image file extension.
I've tried 8bit and 32bit tif displacement map as well as an openEXR. The maps look fine.
I've tested with a simple sphere with quick displacement. If I remove the displacement then mental ray renders fine.
This is using maya 2009, also tried in 2008. Disp map created in mudbox 2010.
Is there a certain setting somewhere that needs to be turned on!?.. I'm pretty sure this used to work before a few years ago so I doubt it's a hardware issue.
I'm really annoyed that it doesn't even want to start the render process at all!...
Any ideas?...
Thanks in advance.


Kunz...
# 2 19-04-2012 , 07:29 PM
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First off, run the render diagnostics.

Rendering menu set>Render>Run Render Diagnostics. Fix anything that it reports in the script editor.

If it still doesn't work,

Rendering menu set>Render>Render Current Frame>Option Box. Change the verbosity level to detailed messages, then click render. Check the output window (I'm not sure if it still exists on Windows) or the Console on OS X, and see if it reports any errors there.


Imagination is more important than knowledge.

Last edited by NextDesign; 19-04-2012 at 07:34 PM.
# 3 19-04-2012 , 08:02 PM
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Thanks for your help.
Turns out that mental ray doesn't like the type of file it is. Strange considering I'm pretty sure this is what other people use. It didn't like the 8bit RGBA tif or any of the other formats I selected from mudbox map extraction. (32bit tif and 32bit OpenEXR)
I converted the 8bit tif to a jpeg, plugged that one into the shader and it rendered. Obviously looked quite terrible but atleast I got a result this time with some displacement.
However I'm still confused to why it won't render using the other map file formats, I thought most are compatible with maya!?...
Could this be a plugin issue?...I would really like the higher quality format map extracts to work with mental ray render.


Kunz...
# 4 19-04-2012 , 08:07 PM
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Make sure you've turned on the EXR loader plugin.


Imagination is more important than knowledge.
# 5 19-04-2012 , 09:21 PM
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Cool, ok thats the exr problem solved.
However none of the tiffs are working. File format subtype or version not supported error. I've turned on tiffFloatReader in plug-in manager thinking maybe that would sort it but no such luck.


Kunz...
# 6 19-04-2012 , 09:25 PM
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Why do you want to use TIFF's? They're the most annoying format, as TIFF is only a container. Every piece of software uses them differently. I believe Maya can load 32-bit TIFFs as well.


Imagination is more important than knowledge.
# 7 19-04-2012 , 09:43 PM
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I was just curious to know why none of the tiffs would work.
I think they were just being generated with a LZW compression from mudbox which resulted in mental ray failing to read them. Saved them out in photoshop with no compression and now they work fine to render with.
Thanks for your help.


Kunz...
# 8 19-04-2012 , 11:03 PM
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I've found that Maya doesn't really play well with compression. Even with RLE compression on a targa, there are cases when loading it into Maya takes a long time. (Which is to be expected, as it has to un-compress the file each time it want's to read it)

It's a trade-off really. You either get smaller file sizes, or faster load times. With small images this is probably negligible, but once you get into 8k textures, it can become a problem, especially when you have 100's of them.


Imagination is more important than knowledge.
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