Share your Mental Ray tips-3DSMax

[Tbonz]

I have used MR (non architectural renders)with a bit of success in the past. Interiors however are giving me quite a hard time. I have modeled a room (properly scaled 24x20 part is behind the camera), no errors on an STL check. Just about the entire room renders fine with the exception of the window trim on 1 side of the room, there I am experiencing the dreaded light leaks. I thickend the trim to nearly 5" did not rectify the problem. Also tried adding a shell modifier no dice. All info I found searching this forum...I tried first

Set Up:

 

Glass is in place- used a method I read (Joske) it allows photons through-also had artifacts when glass was removed from render.

 

Left side

1 MRareaspot(sunlight) .75 multiplier, raytraced shadows, set to disc, adjusted for softer shadows

 

1 self illuminated dome containing scene 54 self illum value

 

Right side

a second very dim(.026) blue MRareaspot to give some fill on the right side of the room

 

I have tried adjusting:

 

Max # of photons both higher and lower

Max sampling radius down from default 1

 

As render cleaned up and became dark I pushed up the energy value quite a bit but it didn't seem to have an impact.

 

Increasing avg GI photons exponentially created some splotches of brightness that was about it.

 

Also tried using FG samples to rectify, to no avail.

 

So, I am hoping someone can offer up some basic formula or explanation on how to get a completely clean render. Every post I have read here has offered up a different solution, I think I tried them all.

 

Sorry for the long post, I truly want to stick with MR as my renderer, but am a bit frustrated.

Thanks for any help, and please no vray/brazil recommendations, that is not what I am asking for.

 

PIC:

 

Todd

[vertexART]

Hi there Todd,

it should be photon sampling issue(usually is), but U said you've tried everything already...

Could U post the .max file of the room, without any interior, only the room, lights and camera setup.

Cheers

[Hao La]

Yes im a mental ray fan too , coul u post ur scene up so we can try to figure out

[Tbonz]

Sorted it out it was the number of photons per sample, and the average gi photons per light. Still have to tweek the trace settings for cleaner shelves and add displacement to carpet.

 

goddam, sorry, I am using this for a portfolio piece, but I can share a thread that helped me quite a bit:

 

http://www.vizdepot.com/forums/showthread.php?t=2014

and this 1 was very informative:

http://www.vizdepot.com/forums/showthread.php?t=1422&highlight=mental+ray+samples

 

There were several threads here as well, I simply searched for "mental ray+samples" and "mental ray+light leaks".(search same in Vizdepot)

Things I found that help in Mental:

Proper scaling, proper modeling, mr areaspots with raytraced shadows. Set the areaspots to disc in the arealight parameters rollout, and adjust the disk size to soften or sharpen the shadows. There are soo many people here with much more MR experience than me

 

[vertexART]

Yes, that looks way nicer, good job man!

Start another one, and post it's WIP's...

 

Maybe a slight displacement on the carpet wouldn't hurt

Great job.

Cheers

[Tbonz]

Thanks Dejan, I appreciate the feedback

 

I will be doing another interior very soon, right now I have some work related projects to do.

 

 

Todd

[Tbonz]

I added displace and changed the carpet pattern yesterday. I had some checkering occuring in my displace map, it has since been corrected.

Tweeking a few last minor things, big render coming after the weekend