AJLynn

Could you elaborate on that boxed light setup? Where is it? are you talking about a rectangular box around the entire scene with a self illuminating interior surface providing you primary light source? I don't think mental ray would be happy with that sort of thing.

Try one where you have the light portals in the windows (arrow points in) and there is no geometry surrounding the scene and no lights except an mr sun and mr sky, FG is turned on and you use mental ray exposure control (the indoor sunlight preset is a starting point). The window glass should be Arch&Design thin geometry glass, which will be dealt with correctly by the renderer. To keep things simple use a matte light gray A&D material for everything else in the scene and see if you can get the lighting to work.

Brian Bradley

Hi Pieter,

Can you post up some screnn grabs of your FG/GI and
light set ups cause to be honest I am really confused
by the description so far.

Regards
Bri

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xeunox

Thank you guys, its looking a lot better

Here is a new render with the settings i have used.(changes marked in red)

Just a quick question, what does the "from outside" switch do on skyportal?

Its still looking very grainy, when i up the shadow samples on the skyportal from 16 to 64 (also deleted/recalc both fg and gi on same settings) this is what i get.(image 2)

Attached Images

	better.jpg (10.1 KB, 37 views)
	settings.jpg (280.0 KB, 28 views)
	image2.jpg (29.0 KB, 21 views)

Tommy Burns

A couple of things I've noticed have only done a few int renderings with mr but I always got good lighting. First I would say is I always use FG at Draft standard setting maybe Low but never medium must take ages to render.
Not to sure on this but you have Read/Write and Read only ticked. I would usually do a test render with none of these ticked so I am getting no saved settings in FG.(I think this is your main problem) Then if it's right I would use the read write option to speed up the main render. Also I would use photon radius this seems to help. I change physical scale to Unitless and enter 90,000 and use a preset in PH.exposure control. Could be a bit off on some of these but I nearly always get great results with these settings. Let us know how you get on?

xeunox

This is where i'm at now, still having problems with grain. suggestions welcome

Attached Images

weo2.jpg (24.5 KB, 31 views)

Brian Bradley

Agree 100% with these recomendations!

regards
Bri

__________________
3Ds Max - Mental Ray - VRay - Brazil Training Modules
www.mentalboutmax.co.uk
The MBM Blog
www.mentalboutmax.blogspot.com
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www.vrayelite.com

xeunox

hey thomas, thanks for your input. Most of my work i do for print, and i need to render out a4 300 dpi tiffs, what i do is calculate the FG on a a4, but at 72 dpi, while saving the fg file, i have a dual quad core system, medium settings doesn't take to long, about 5 minutes for this specific image. After this is done, i up the dpi and lock the fg, its works well. If i use draft quality, its gives me artifact, not always though. Is this wrong?

while i'm on the subject of rendering, i want to know how you guys render out your more complex scenes, with lot of geometry it gets difficult to navigate through the scene, and takes even longer to render. I know putting everything at once is the wrong way to do this, however, when one hides layered/grouped geometry it gets excluded form all sorts of light/shadow calculations. Compositing after in photoshop is easy, but it never looks right. I use a global material override with a ambient occlusion MR material, on everything, as a final layer on multiply setting. maybe someone can give me a better solution.

Tommy Burns

Hi pieter
Not too sure what you are doing with the dpi thing never use this workflow. If I get artifacts usually it is something to do with photon settings not high enough or too high. Using the photon target radius seems to help although some scenes I don't even use photons (Trial and error).
As far as rendering out your scene Jeff Patton has a post in here about "subset of scene" it is a hidden shader and it does all you want for compositing it's brilliant and easy to use. You can probably find the tutorial on his web page.
Keep us posted how your getting on?

xeunox

fyi tommy, DPI (dots per inch) has to do with the amount of pixels in a square inch, large print quality is usually 300dpi, newspaper 150dpi and your screen has a resolution of 72dpi.

A standard A4 paper real world size is 297x210mm.

a4 high quality render @ 300dpi is 3504x2479

i use the print size wizard under the render toolset.

Tommy Burns

Cheers Pieter!

Just had a look at this and it's a handy tool I always just used the render scene dialog. I don't understand what this has to do with FG and saving an FG file. I think you can save a smaller FG sometimes and then print at a larger resolution but i never do that I always create the FG file at the size I'm printing and if it's right I save it and use read only for speed of render. Don't know what's right here maybe someone else might clarify.