Mental Ray Portal Light Issues

#1

I have a simple scene setup with a daylight system and an empty room (hollowed out cube with one window) sitting on a plane. Render preset is mental ray daylighting (with gi then enabled) and exposure control is mr photographic daytime indoor.

When I place my mr sky portal in front of the window (directing it inwards) and render I get the following error…

“photon emission shader returned miFALSE: aborting photon tracing”

if I ignore the error and continue to let it render I still seem to get an accurate result. If I remove the portal and re render the error disappears, but the render is now obviously near black (with little light getting in).

Can anyone one help me with the error ?

Thanks

#2

Did you turn on “emit photons” in the mentalray properties ?

Regards,
Mike

#3

Though I couldn’t find any “emit photons” setting in the mr render rollout, I AM emitting photons (average of 20k per light, all objects are generating and receiving GI and caustics etc)… If you could be more specific with the location and name of the setting I can check it, but I am pretty sure im semitting photons.

#4

With a similar setup as yours I received the same error when generating a photon map. These are the steps I took to resolve this:

  1. Put the Sky Portal settings back to default.
  2. On the Render Setup Dialog under Indirect Illumination put the GI, Volumes and Light Properties settings back to default.
  3. Under the Processing tab “Clear Geometry Cache” (if enabled).
  4. Delete all Photon maps and “Generate Photon Map File Now”
    After this there were no errors.

Now I’m increasing my settings gradually, so far there have been no errors…

#5

I tried the above but still resulted in same error… I have attempting resetting all render settings/presets with no solution…

I HAVE managed to fix the error with a ‘workaround’ solution…

I saved the scene, Created a new scene… and merged the two scenes… only merging geometry. Using the same render preset used in the original scene I now have no error.

I CANNOT find a modified/different setting in the original scene that could be effecting/causing this… but it seems there is one lurking somewhere… as exporting ‘just’ the geometry to this new scene and re-rendering with a newly and identical room/daylight system/portal etc is now working fine…

If anyone still has any ideas on what I can check in my original scene I’d really like to know… as its ‘bugging’ me :wink:

#6

Sorry on wasting your time with resetting settings: I received the error again.
Thank you for sharing the ‘workaround’ I shall certainly try it.

I’ve run out of suggestions but this may help jog someone’s memory:
I found ticking “Enable” in:
mr Sky Portal > mental ray Light Shader
stopped the old “photon emission” error and opened a new can of worms:.
Mental Ray logged the warning: API 0.0 warn 302032: while defining light “mr sky Portal01|Light”: light has no light shader
To rectify this I put the light shader “Light Infinite (base)” in:
mr Sky Portal > mental ray Light Shader > Light Shader slot
This got rid of the Mental Ray errors and warnings but now the scene appears to be over exposed in light…

#7

By any chance did you have the Daylight System set up with:
mr Sky > mr Sky Parameters > Sky Model > CIE

And the Sky Portal:
mr Sky Portal > Advanced Parameters > Color Source > Use existing Skylight

By changing CIE to Haze Driven and/or changing the Sky Portal’s Color Source to "Use Scene Environment " Mental Ray has been error free (so far).

#8

Hey, did anyone come up with a solution to this problem. I am actually using Maya 2009 and I am getting the same exact error. Someone please shed a little light on this. Thanks

#9

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