I am trying to learn how to use MR shaders e.g. Mia_material_x. I am getting no where fast and the questions are mounting!

I am having the usual problem that every MR noobs is having. My mia is rendering out completely black. I have read alot of the maya help and the MR manual but they only give me references of parts of the overall picture. Do you guys have any advice on where I can go (sections of the maya help, MR manual, website, tutorials etc) that can give me the full story about how to use MR shaders?

I am so confused.

1)Is the complete black render something to do with the lack of tone mapping, gamma correction? Or something to do with not using GI and FG? At the moment I have turned off all GI and FG to speed up test renders. If GI and FG are required for mia to render properly, what is a good workflow for texturing and shading bearing in mind the long render times. I have optimised my GI and FG render to no less than 4 min per frame! So trying to texture and test render using this set up is not practical.

I have planned to turn off all lights and use a maya ambient light to allow me to get rough texturing done and then switch to full GI and FG. However, this doesn’t work cos my mia just renders out black.

2)The MR manual also mentioned that mia “conserves energy” therefore it is important to make lights obey real life behaviour ie have a 1/r2 decay. I am rendering out a standard interior room with a window that has direct sunlight. If I use the 1/r2 decay, my render is almost black. I can increase the intensity of the photons but I reach the maximum value that maya allows me and it is still is too dark. Do I have to use different intensity units? If so, how do I switch to a different intensity unit?

3)When I do turn GI and FG on, the mia renders out fine (though it takes ages) but very dark. I applied the photographic toner mapping to the camera lens shader in the hope that it will “even” out the colour ranges but it just renders out total blackness. There is no mention of how to apply the photographic toner so I just guess. In the hypershader, I applied the toner to the camera node by MMB drag and using the default connection. Is this the correct way of doing it? If so, why am I getting total blackness?

Any advice guys?

3DS Max 6 to 2009, Maya 2010
Windows XP Pro x64 SP2
NVIDIA Quadro 1700, Quad Core 2.67GHz, 4Gb RAM
http://www.beanboxanimation.co.uk

mental ray in Maya is confusing.  The best thing to do would be to zip and upload your scene for us to take a look at it and find the problem.

Is your scene modeled to the correct real-world size?  If your units are set to centimeters, for example, then your model should be the appropriate size in centimeters.

I have planned to turn off all lights and use a maya ambient light to allow me to get rough texturing done and then switch to full GI and FG. However, this doesn’t work cos my mia just renders out black.

The Maya Ambient Light doesn’t appear to be compatible with the mia shaders.  They will render black.

I am rendering out a standard interior room with a window that has direct sunlight.

How are you creating your direct sunlight?  Are you using a “Physical Sun and Sky”?

Please zip and upload your scene, if possible.  Otherwise, can you describe in detail your scene and lighting setup.  And post images showing your settings.

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

Also, check out this recent post.  It may not be directly relevant to your current issue, but it may be helpful one day.

http://area.autodesk.com/for...ometric-lights/page-last/

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

Cheers for the reply Valen. It seems both of us are in a very similiar situation. I too come from a 3DS background and trying to learn Maya. Very confusing.

I appreciate the offer of zipping my file (and I might take you on that offer later!!!) but that would only solve the immediate problem.

I am trying to learn the entire workflow of using MR shaders. My first over-arching issue is to figure out how ppl texture whilst using mia material when the render times are so long. Ppl must have a work around to this to make it less painful.

With regards to ya questions:

1) the scene is to scale. Unit=cm
2) lights are “standard” spot and area lights. Perhaps I should consider switching to mia_photometric_light?

I will upload the files tomo (if I can).

3DS Max 6 to 2009, Maya 2010
Windows XP Pro x64 SP2
NVIDIA Quadro 1700, Quad Core 2.67GHz, 4Gb RAM
http://www.beanboxanimation.co.uk

If you go to the tutorials section of this site ( http://area.autodesk.com/tutorials ) and enter “maya mental ray” in the Search box, it will return a bunch of tutorials.  You probably won’t find one that suits your needs exactly, but overall you will get a better handle of the workflow.

Note that if you’re using mental ray materials, then you need to have mental ray as your active render (not Maya Software renderer).  Obvious, yes, but worth mentioning.

There are ways to speed up render times when texturing.

-Use “Render Selected Objects Only” within the “Render” pull-down menu in the “Render View” window.
-Disable GI and FG (like you have already)
-Instead of rendering the whole screen, select a smaller region to render.
-Display your textures in the viewports so that you don’t have to render in order to see them.
-Turn down your sampling settings in the “Quality” tab of the mental ray render settings.
-Choose a lower “Quality Preset” in the “Quality” tab of the mental ray render settings.
-If your lights are casting shadows, decrease their sampling settings.

Switching to photometric lights will help your GI rendering, probably won’t make much difference in your render times.

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

I’ve found this site to be useful…

http://www.djx.com.au/blog/

http://www.djx.com.au/blog/2010/03/07/maya-linear-workflow-in-two-steps/

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

Thanks for all ya advise. I will check out the links when I have abit more time.

With regards to one of ya response;

One of the point about using mia is that it needs GI and FG so I cant just turn these off to texture because it wont render. If I turn them on, then texture and test render becomes too time consuming. So one of my important querry is...How do ppl texture whilst using mia?

ps tried to attached the file but having problem (ie accidentially deleted). Will try again tomo.

3DS Max 6 to 2009, Maya 2010
Windows XP Pro x64 SP2
NVIDIA Quadro 1700, Quad Core 2.67GHz, 4Gb RAM
http://www.beanboxanimation.co.uk

You can render mia materials without having GI and FG enabled.  See this image…

Also, in case you didn’t know, you need to zip your scene before uploading.  Or else it won’t work.

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

	Attachment

I only had one light in that scene.

Hopefully you can recover and upload that scene.  Or else post a new scene with the same problem…

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

Here is the attached scene

3DS Max 6 to 2009, Maya 2010
Windows XP Pro x64 SP2
NVIDIA Quadro 1700, Quad Core 2.67GHz, 4Gb RAM
http://www.beanboxanimation.co.uk

	Attachment
temp01.zip

How was this scene created?  Was it imported from another program?  I ask because there are a bunch of transform nodes and stuff all over in the Outliner.  I had trouble trying to assign new materials to the objects because they did not want to let go of there initial shading groups.  This could cause other weird behaviors as well.

If you change your ambient light to a Point light, then your mia materials will render.

I saw you were using an Area Light and a Spot Light for your scene.  Are you aware of the mental ray “Physical Sun and Sky” shaders?  You can enable them in the “Indirect Lighting” tab of the “Render Settings”.  Enabling this creates the following:

-a Directional Light with “mia_physicalsun” assigned as its Light Shader and Photon Emitter.
-mia_physicalsky and assigns it to the mental ray “Environment Shader” of your camera.
-mia_exposure_simple and assigned it to the mental ray “Lens Shader” of your camera.

I made up a sample scene and attached it.  I’m not sure if you’ll be able to open it though if you’re using 2010.  I included a .mb and two .ma files.  One of the .ma files has been edited to show 2010 instead of 2011 so maybe that will work…

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

	Attachment
lightsetup.zip