a few mental ray lighting questions

[cakewalkr7]

I've been working through a couple of books and a bunch of tutorials and now I'm trying to model, material and light my first scene. I know I still have quite a bit to do with the materials, but I'm concerned right now about the lighting. I'm using mental ray and I have the final gather set to medium quality. All of my lights are mr omnis w/ ray traced shadows w/ a max quad tree depth of 7. Here are some questions/concerns I was hoping some of you mental ray/fg gurus could answer.

 

1. In the images with lights, there are 6 mr omni lights with a mulitiplier of 1 near the light housing in the ceiling. And there's an mr omni in the hanging light with a multiplier of 12. I had read that the amount of ALL fill omnis should usually add up to one, so basically my six ceiling lights should be set to around .17 not 1, but even when set to 1, it doesn't brighten the scene like I thought it would. And, shouldn't the main omni set to 12 really brighten the room? I'm wondering why it's not a very bright white and also why the ceiling lights aren't kind of glowing white from the mix of the omnis right below them and the self illuminating white material on inside of the light housing?

 

2. In all the scenes, but obviously most pronounced in the 1 PM w/ no lights scene, there a lot of ugly noise. I've rendered another scene with f/g settings at high and it still had quite a bit of the noise. I thought that would be in the f/g settings, but I just can't seem to get rid of it.

 

3. In the 7pm scene, there is a shadow going across the fireplace and left window with a lit area above it. I can't figure out where the lit area is coming from. Does it seem apparent to anyone?

 

4. Why are my lights from the ceiling casting shadows on the floor?

 

Does anyone know of good tutorials on lighting in max with mental ray and final gather? I've worked through the included max tutorials but I'd be interested in anymore you all might know of. Thanks!!!

[alias_marks]

Here's some good mr tut's I've found over the last year or so. However they don't cover the most recent version of MR, from what I understand, has changed quite a bit.

 

http://lakehao.home.comcast.net/tutorial_intro.htm

 

As far as your questions go, Could be lots of different things. The best way is to start with extreamly simple lighting, and then work up from there. Start with one omni light, and then work up from there. Don't overcomplicate things. Adding too much stuff makes it very hard to distill the problem.

 

A couple things I think may help with your problems. Make sure "overshoot" isn't checked in your lighting settings. It looks like you don't have any falloff/decay either. I would make sure those settings are accurate, espically with interior lighting scenes. Direct lights from outside should be the only lights with no decay.

 

Make sure you don't have any exposure control f'n things up. I've had lots of trouble just because I had logarathimic exposure control checked in the environment settings.

 

Good luck:cool:

 

DownTown MikeBrown

[ipxstudios]

Start with single sunlight, then you will get your daytime colors and shadows correctly.

[vizwhiz]

which version of max are you using?

max9 mental ray is different Than previous verions

 

There is a (somewhat) useful interior scene Tutorial in max9

it doesnt look like you are using These method for your interior scene

 

i just got max9 and i am working Thru This interior Tutorial as we speak

The FG settings make a LOT of difference in quality of what you are Trying

 

To do

 

if you are using max8 or

 

Randy

 

(ok, not very helpful but you need To specify which version of max u r using)

[cakewalkr7]

Thanks everyone for the replies.

 

Michael, I'm using Omis, not spots, so I don't have the overshoot or falloff/decay options available. I do have attenuation which I am using. I do have logarithmic exposure set up because from everything I read, that's what I should use when using the daylight system. I'll check out the link you posted. Thanks!

 

Randy, I'm using the v9 trial version (my other version is waiting at home for me when I get back from christmas vacation:)). I did work through that mr interior tutorial and it seemed straight forward enough, maybe I should go back and revisit it. I just figured that if I was using the high setting in FG, it would probably take care of all that ugly noise.