3ds max error

Hi guys I have this strange error appearing, I tried to google it but nobody seams to be aware of what it is,... the error is - PHEN 0.4 error: a ray encountered an invalid colour, (NaN), using black instead, I hope you can see in that small render test, it has like a random colour effects? anyone came across this issue? I am using mental ray, daylight system, for environment mr physical sky, with indoor daylight exposure control, also I have the mr sky portals, final gather is on, diffuse bounces - 8, fg point dencity - 1.0 , reys per fg point - 500, I don't think that the issue is with the setup, because I rendered it from a different, angle and it was fine, I was thinking that the mr sky portals were overlapping, so I redraw them, and the issue is still there, I hope you could help me with this, haven't slept for like 40 hours now

This could be related to your lighting setup. Are you using any other lights besides the daylight system?

It could also be a problem with one of your materials. What type of materials are you using?

But it's probably a combination of the two. The light shining on the material is probably causing a problem with the reflection/refraction which would explain why it renders correctly from a different angle.

This is just my best guess though. I have never seen this error and would not be able to reproduce it even if I tried. You will have to do some experimenting on your own. Try removing or replacing materials and see if the problem goes away. Also, try turning off some lights, if you are using any, and see if the problem goes away.

hmmm,.... I checked, the light lister, and in the scene there are - mr sky lights, sky and sun, and mr sky portals, I have objects illuminating in the scene, but they cant be the issue because I rendered them from a different camera view, and it was fine, at the moment I am using, art&design materials, architectural, standard, and multiple, 3 materials in one, but they are all above. I think you might be right about the reflection and refraction, what would you suggest just replace the materials, or change the refraction and reflection settings? I just notised, when I reduce indirect ilumination to - 0 bounces, 200 rays per fg, initial fg point dencity 0.1 it seams to fix the issue? but of course the renders are low quality, any suggestions mate?

Well, like I said, I've never seen that error before and I can't reproduce it on my end, so you just need to be a detective and figure out what's wrong.

I just re-read your original post and saw that you have bounces set to 8? Why do you need so many bounces? You could reduce that to 4 and still get a very good looking render. I generally don't use more than 2 or 3 bounces in my renders.

I would bet the bounces are the problem.

your bet was right, it was the bounces that caused the issue. I don't know, I have illuminating objects in my scene, but they aren't very bright, so I thought I increase the diffuse bounces, would give them more brightness, but yes, I reduced the bounces to 3, and it renders fine now, so thanks for your help mate :wink: