View Full Version : Mentalray Standalone and lightlinking

May 4th, 2009, 11:47

I am new to standalone . I am facing a bit of a problem regarding lightlinking..

I have an generic file in maya which contains two spheres ... one of the sphere is linked by default to a directional light , and the other sphere is delinked form this light ...

when I export the scene to an mi file and render it in standalone .. It gives me a error about lightlinking and renders the scene ignoring the light linking ...

How do i save the linking info in the mi file ?

Does mentalray standalone support maya light linking .. ?

Plz help me out .

******************************* EDITED **********************************

I figured out the problem and found the solution ... but It has resulted to a new problem :(

My standalone version in for maya 2009 and the mi file was generated in maya 8.5

so I did some rnd ... lol

I exported the same file in maya 8.5 and in maya 2009 in ascii and compared both the files in wordpad..

The coding for the mayatomr exporter in 2009 is way different than that for 8.5

lighlinking in mi file from maya 8.5 is written as

incremental shader "lightLinker1"
"maya_lightlink" (
"ignoreLinks" [

and in 2009 is written as

instance "pCube1" "pCubeShape1"
light "exclusive" ["directionalLight1"]
material ["initialShadingGroup"]
caustic on
caustic 3
globillum on
globillum 3
0.694343 -0. 0. -0.
-0. 0.694343 -0. 0.
0. -0. 0.694343 -0.
-2.17934 -0.46993 -0. 1.
end instance

So as you see the whole coding is different ...

Now my problem is .. is there a way to render a maya 8.5 file in mentalray standalone for maya 2009 ?

May 5th, 2009, 20:22
exporting an .mi file from a previous version of Maya and rendering with a Standalone mental ray of the following Maya version is supported, since the original shaders are kept in the packages like mayabase for backwards compatibility. On the other hand, if you have the Maya file, it is best practice to load it into newer versions of Maya for re-export to an updated .mi file that best fits the feature set of the current standalone mental ray.

May 6th, 2009, 14:48

Thanks for replying ...

I agree with you normally most of the softs are backward compatible ,,,

It does render out the scene but it only gives me errors for light linking ...

As you said i did the same thing .. reexported the file in maya 2009 .. but where i work we have a 8.5 platform and we are testing out mentalray standalone for rendering solutions .. and the standalone software that we are using is the latest one .. So I need to figure out a way to export the 8.5 file so that its lightlinking info is completely compatible with the latest version of standalone ..

Also I would like to know is there a specific way of exporting hair from shave and haircut ?

May 6th, 2009, 15:55
If your company is testing for mr standalone, couldn't it also test with just one seat of Maya 2009 (SP 1a)?

There were pretty significant changes in light linking, and that is several versions of difference from 8.5. What were the results, when you re-exported with Maya 2009?

If the test were successful, I would highly recommend matching the Maya version to the standalone version.

There are several ways to export hair from shave and a haircut. I would go with the hair primitive created by a geometry shader rather than explicit geometry, but for the exact details I'm not quite up-to-date.

May 8th, 2009, 11:18
Hi bart
Its good to hear from you too ,,,

As stated in my earlier post .. we have already tested with maya 2009 and it workes perfectly with mentalray standalone for maya 2009 .. I have no issues with that ,,

The problem is that ongoing project is on maya 8.5 ... and the company is unwilling to risk an upgrade to 2009 on this ongoing project .

So was hoping there was a workaround :(
As you have stated, I did figure out that there has been an enormous change in the coding ,

And about shave I sill need to figure out how to export it for mi :(