PDA

View Full Version : Mental Ray Photon error 3d Studio max 7 PLS READ


Saku-Pekonmaki
04-29-2005, 01:06 PM
Hi and thanks to all of you who take time to read this thread.

There has been tons of discussions on photon errors on cgtalk, and unfortunally this is just one more.

first of all I want to let you know that I have read the discussions on this problem in the following threads.

http://www.cgtalk.com/showthread.php?t=188793&highlight=photon+error
http://www.cgtalk.com/showthread.php?t=164301&highlight=photon+error
http://www.cgtalk.com/showthread.php?t=108148&highlight=photon+error

and many more under the search of photon error.

Jeff pattons threads has been a good help :)

many of you who are familiar with Mental ray know that by using a dome , will prohibit the photons from escaping the scene and make errors. And many would also like to add that by putting higher amounts of photons would also help.

I have done everything that is possible to try to fix this problem, but still Im getting this "no photons stored errors" "#$%&!"#% , Ive hidden objects, turned on and off lights, made new objects and deleting objects, and still this error is coming upp.

Im so frustrated by not knowing what could cause this. I nearly lost my temper and destroyed my desk. :)

Im wondering if the scene is totally fd up? or the file?
could any one help me PLSSSSSSS ( pretty, pretty please)

Do not worry of the jpg files missing, they do not affect the error anyhow and would only make the file bigger. I use mostly default materials.

here is the file its aprox 4,5 mb
http://www.nmedia.is/saku/photon_error.max
for u who use rar aprox 500k
http://www.nmedia.is/saku/photon_error.rar

ies file is also required for some photometric lights wich is here
http://www.nmedia.is/saku/weblightnice.IES



Ihope that jeff patton can read this :)

Saku-Pekonmaki
04-29-2005, 01:35 PM
if there is some objects or materials that need explanation pls post here so i can rply.

JeffPatton
04-29-2005, 02:31 PM
To troubleshoot the scene, try this:
1) Delete all the lights in the scene.
2) Remove both domes that you have surrounding the scene. (It looks like the inner dome is blocking the photons from the building).

Now, starting without any lights, use a MR spotlight for the sun. The reason? You can easily focus it on the building without wasting photons and you will have area shadows.

Change the GI radius to 5.0 and global energy multiplier to 1000.0. Turn off Caustics and FG. Now you will be able to see the photons in the building, and easily adjust them before enabling FG.

Next, I'd start adding interior lights. Run test renders occasionally to make sure you don't have any problems with photons (which would most likely stem from placing the lights inside a light fixture that does not have a photon map to allow the photons to pass through).

Once you have all the interior lights in place and the GI photons working as they should, then enable FG with a small sample amount and work up from there.

Saku-Pekonmaki
04-29-2005, 03:22 PM
yeah with dome part i deleted one of them. but that did not make any diff.

I just tried it as last option thing but forgot to remove it again before posting :)

Saku-Pekonmaki
04-29-2005, 03:32 PM
it appears as infinite light does not create GI when using mr spot as sun?
could that be right?

Saku-Pekonmaki
04-29-2005, 03:41 PM
Im so releaved!

Thank you alot Jeff.

i tried before to change the light from mr spot to photometric sun and back but that still gave me errors. so now i deleted all the lights and did as u suggested and .. VOILA!

no errors

im like "!#$%#&" ? :/

floze
04-30-2005, 12:53 PM
many of you who are familiar with Mental ray know that by using a dome , will prohibit the photons from escaping the scene and make errors. And many would also like to add that by putting higher amounts of photons would also help.
Using a dome to 'catch' the photons doesnt help anything. This way, the photons are getting stored in places where they're absolutely not needed, and beside that the photonmap lacks of detail where you need it, and more photons need to be used unnecessarily - memory explosions (figuratively) and long emission times are the result of this.
If you get emission errors, there's something wrong either with your light (spotlight cone too wide, usage of infinite/direct lights, energy too low, etc.), or your photon shaders are set up incorrectly or even non existant. Deriving photon shading from material shader is not always the best choice. Play around with dgs photon shaders - they're fast and easy to set up.
As Jeff Patton said, one very important note is if you get emission errors to turn off caustics if you dont have specular or refracting materials in your scene.

Saku-Pekonmaki
05-05-2005, 08:19 PM
Yeah i noticed!
Dome is only good to create a fake GI with final gather on only.

thanx floze for ur input.

I think it would be good to put up a locked thread " How to setup Mental Ray for dummies" :)

CGTalk Moderation
05-05-2005, 08:19 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.