Rendering To Texture using MentalRay

[JCD37]

Hello,

Whenever I try to render to texture using Mental Ray, the frame buffer view seems fine (renders OK), however when I try to open the saved file, I get either a black image, or a black and white noise.

I was wondering if anyone else has this problem, and if there is any fix around it (as I am writing I am using Max 2017, however I tried with both 2013, 2014 and 2015 and get the exact same results).

Thank you.

[Alfred.DeFlaminis]

Hello @JCD37 and welcome to the community,

Can you attach a simple file that has this issue?  (A box or sphere or anything.)  It would be easier for me to find a solution or figure out what is wrong that way, there's so many options in RTT that I want to be sure we're on the same page and using the same settings.  Thanks very much!

Best Regards,

[JCD37]

Hello, and thank you for your reply.

I have attached an example scene and the rendered output (tga saved by max).

Thank you!

[Alfred.DeFlaminis]

Hello @JCD37,

Thanks for posting those!  Ok the problem here is that the 'mental ray' material isn't supported for this, but other MR shaders are such as Arch and Design.  Just switch to a different shader.  I also tested in 2014 and got the same behavior with the 'mental ray' material.  Please let me know if you have any questions.

Best Regards,

[JCD37]

Thank you for your reply, the problem is now clarified.

However, I am left with one more question:

What is the correct workflow for rendering to texture a map/image without having any lighting information affecting it.

Or in other words, in the scene example I gave, how would I output the checker pattern in a texture - without any light/shadows/reflections or anything else. Previously I was using the surface shader input of mental ray material for getting this result.

Big thanks!

[Anonymous]

well that's simply in your Mat Editor..

Set up your map, say checker, tweak whatever params you like....then Utilities>Render Map...I'm sure you can figure out the rest....

[Alfred.DeFlaminis · Accepted solution]

Hello @JCD37,

What I often do is use an instance of the map or map network in the diffuse and self illuminated slot of a standard material.  Then I bake the pass as "Complete Map" with no spec or anything.  Or if your preferred renderer has a Self Illuminated Pass, that's basically the same thing as a surface shader in the mr material.  You can do it with an Arch and Design as well but then you have to turn off reflectivity so I don't bother.  

However Vusta's method also works on some level, but you need to be in the map channel you want to bake in the material.  If you are on the top level of the material, it will be grayed out.  Also, it doesn't pay any attention to the object's UV's (since it's baking it out as applied to a plane)  so I'm not sure it's super useful for baking procedurals into UV's.  For example if you were using a cellular map to put scales on a lizard for a bump map and wanted to bake that procedural to a 2D map, it wouldn't be great for that.  

Also note that in the file you attached it's making new uv's on channel 3.  The automatic mapping is a bit dodgy for most applications, I think it's best to "Use Existing UV Channel" in the RTT menu.  To each their own, however.  

EDIT: Added a note to put the map in diffuse too in the initial sentence.  It wasn't clear.  

Best Regards,

[JCD37]

Thank you for the reply, everything is clear now:)

Cheers!

[Alfred.DeFlaminis]

I'm glad it's working, thanks for the confirmation @JCD37!  

Best Regards,