View Full Version : where's my sky?

2008-06-03, 08:01 PM
I've got all the mental ray settings (mr Sun, mr Photo. Exp. Control, mr Sky, and mr Physical Sky w/ a jpg of a sky and clouds attached) turned on at default settings (i think) and I still get a sky that fades from basically light hazy to black as it goes up. The map isn't showing up, and the rendering as a whole is darker than it should be.

Any suggestions?

2008-06-03, 08:14 PM
I forgot to add that I can get the sky map to show up in the render preview window. Everything "seems" fine in the preview.

2008-06-13, 02:37 AM
How did you apply the image of the sky to appear?

2008-06-16, 07:38 PM
I followed some tutorial about making taking a new material slot. Then...Get Material-->mr Physical Sky. From that material's settings, I checked "use Custom Background Map" and found my sky jpeg.

I've had that unchecked for a while trying to at least get a decent blueish mr Sky. Since my first post I've at least found that if I bump up the mr Sky and mr Sun multipliers to about 4.5 that I get a blue sky, but it's a pretty unrealistic (and obviously uncloudy) deep blue sky.

2008-08-14, 01:52 PM
I found another solution...get your company to purchase the ultimate RPC package and get your choice of near perfect skies! The only thing is, mental ray takes the "average" of the surrounding color and bounces that color light around the scene inside your environment "bubble." The skies are really good.

I've had to trick it by selecting a white ground plane (which will bounce good white light around) rather than green grass (which turns my scene/sky greenish- it looks like a tornado is coming!)

2008-08-16, 06:38 AM
Welcome my friend!But i don't satisfied this sky problem.If they can't show custom background ,they don't allow custom map background with daylight system(mental ray).

2008-08-16, 06:58 AM
I know this is gonna sound whack but it worked for me. Go into your exposure panel and change your physical scale to manual and bump it up to about 80,000 to 100,000.

2008-10-08, 04:44 PM
I know this is gonna sound whack but it worked for me. Go into your exposure panel and change your physical scale to manual and bump it up to about 80,000 to 100,000.

Thank you for this. This makes sense since the physical scale controls the illumination of standard lights / environmental maps. Since it doesn't effect the overall illumination of the rendered scene this work around does the trick.

2009-10-08, 01:39 PM
It seams everybody has a problem with mr and custom background...
First: I got it to render OK, but what kind of mapping do you use? screen squeezes the 4096x2048px map (ArchMat Sky.Day.Cloudy.Low.jpg) to whatever i render. In my picture i set it to cylindrical with the size 0,005m x 0,005m or its way to big, or just displays wrong, because its the only number that really works...

Second: Horizon height, cant get rid of the little blue slice.. :(

Third: It ain't showing up in reflections! :(

2009-10-09, 03:37 PM
You have to unlock some of the hidden shaders in order accomplish what you want. Have a search on google and it should pop up. Specifically look into the ray type switcher.

Also Jeff Patton is the man when it comes to this stuff...he's got some videos on gnomonology that i highly recommend buying...and he's a god guy, always willing to help.

2009-10-19, 01:54 PM
Thanx ill see what i can find on google on the ray switcher, kinda rings a bell..

And also take a look at Jeff Pattons stuff :)