FG causes renders to look 'grey' on exterior scene

[berliner]

Hi, I've been working on an scene of a building. I'm using mr Sun and mr Sky, as well as A & D materials for everything. When I render with Final Gather on, the materials all look washed out in a grey tone, and this happens when I use it with GI simultaneously on as well. But if I use just GI with FG off, the correct colors are actually showing up. I've read in many places that FG is the way to go for exterior daylit scenes, but I think I'm missing something. I'm trying to get this to look as realistic as possible- should I even being using a daylight system as opposed to an mr area spot or something? Another big problem is that the windows are not reflecting properly, and I'd like to know if anyone can suggest realistic architectural glass that I should be using? I appreciate any help and comments!

[Crazy Homeless Guy]

The Mental Ray Sun and Sky along with FG/GI is a weakness of the engine in my opinion. I have got very few nice looking images out of it, they are routinely tinted to greenish blue. I would highly recommend using an HDRI to illuminate exterior scenes in Mental Ray. Your results will be superior.

 

EDIT: This may also be a gamma issue. Post your images like others are suggesting.

Edited March 11, 2010 by Crazy Homeless Guy

[Justin Hunt]

What are your exposure control settings?

 

jhv

[natski08]

kindly post some wires, setting and the render image you are talking about. lets see what we need to fix on your setting.. for now on i can't suggest unless you show me the scene setting.. i think you just miss something on your setting.

[mattclinch]

leave the sun and sky values at 1.

change the ev value to 13 - 13.5

change the exposure curve values to shadows - 0, midtones - 0.7, highlights - 0.13

you may also want to instance your physical sky map into the material editor and override the brightness of the sky to a value of 2. i find the sky is always too dark by default.

 

hope this helps. its my standard setup for exterior sunlight renders.

[berliner]

Also- where can I find the HDRI lights? I can't seem to find them. I'm on 3ds max 2009 btw.

This may also be a dumb question- but any time I make any updates to the original AutoCAD file that I've imported the model from, how can I maintain the materials as they are in 3ds max without having to reapply everything everytime I reload?

Here are the control settings as well as another render- but I noticed now that it's showing a white outline around the building also, geesh...Thanks alot for the help!

[natski08]

There is nothing wrong with your with your light setting.. i think better do the texture directly in 3d max. and if you want to make it not gray anymore or make it more white put a 2 or more on your diffuse bounce. and use only mr sky for better result.

 

For glass better put something to reflect on your scene like trees or image in front of it. and try put some curtain to make it more looks realistic.

 

For me i leave the sun setting by default and just changing the photographic control value.

 

About the white outline I think it's on anti aliasing problem use mitchell and raise your sample per pixel to 1 / 16 or higher.

 

sorry about your other question I never do cad modeling.. I model directly in max.

[neko]

This may also be a dumb question- but any time I make any updates to the original AutoCAD file that I've imported the model from, how can I maintain the materials as they are in 3ds max without having to reapply everything everytime I reload?

 

it's not a dumb question at all. are you file linking or just importing ?

 

if you are file linking your autocad model, make sure when you reload it to look at the 'advanced' tab and check off the two options for using scene materials on reload.

[TSuess]

Gamma, Gamma, Gamma. 2.2 in 2.2 out.

[Justin Hunt]

Set your sky, ground colour to a 80% grey rather than black

Photons, turn OFF merge nearby samples and Turn ON Optimise for FG

Turn ON All objects generate GI

 

You dont show your FG settings so I'd suggest using the DRAFT preset with 0 bounces, any more are disregarded anyway when using Photons.

 

I agree with Matt's Exposure settings (glad to see someone else dropping the Mid tones as well), and sun settings

 

For the outline, what file format are you saving to? TGA's tend to to this

 

jhv

[berliner]

Thanks alot for the tips guys! I followed what was suggested w/ the exposure controls andthe FG/GI settings, it really helped. But the scene is really bright now though. I will play with the exposure and sun a bit to find a balance. I usually save as tga and tif- those outlines were in the tga- I'll remember that . Appreciate the help!

[berliner]

Thanks alot for everyones tips! they really helped. Especially the FG/GI settings. It's looking way better. Just working on getting it to be more 'crisp' as far as light and shadows go...and as realistic as possible- obviously. Here's a sample of it with the updated settings. Let me know if anyone has another suggestion.

[RevitGary]

You seem to have your sun near the same angle as the camera. I would put it to the opposite side and lower it more like 6 pm. This would give you more dramatic lighting and a shadow across the face of the building inset.

 

aslo if you make your ground plan a darker grey the white will stand out more

Edited March 13, 2010 by RevitGary