Maya Trouble. MR Physical Sun/Sky "use background"

Eric Wiley

Hey, I have a scene that I am lighting with Mental ray physical sun and sky in Maya 8.5. The sky appears blue or whatever time of day it is according to the physcial sky. I want to set a picture as the background instead, plain and simple. When I set an image under the "use background" everything renders correctly except the background is black. How do I set a picture as the background or use a skybox with mental ray physical sun and sky. Any help would be great.

pliang

I did this once and I believe the problem lies within the ground and night color...try jacking it brighter.

And did you have a enclosed skybox?

Eric Wiley

Yeah..I tried messing around with the ground and night color but the background stayed black. I cannot believe how difficult this is to do. It is so easy to do in 3dsmax. All I want to do is replace the physical sky with a background image.

Here is a WIP render of my scene. I want to replace the MR physical sky with a background image.

Illusions

Is that default MR Physical Sky? Because when I use the default all my colors get washed out horribly...

I'm going to be experimenting with physical sky, so I'll post anything I find out thats relevant to getting a different background image up.

Eric Wiley

Yeah..this is just regular sun and sky. I haven't changed anything, everything is default. Well, I will check back here in a few hours, for now I'm just going to export my render as a PSD and composite the background in with photoshop. Thanks

Jesse Moody

wow i know you are having issues but just wanted to say cool scene.

pliang

Its the kid friendly version of Crysis.

IxenonI

I can´t help you with the background thing.

The washing out of the colors comes from the fact that mental ray and the skylight system work in a different gamma space then everything else.
You have to connect a Gamma correct node in front of your file textures (At approx. 0.45). With that, the washing out of the colors does not happen, the problem is that you cannot view these textures in the viewport (they appear black).

pliang

Eric, I think what you should is whatever the camera is you're using...say if its persp try going into Outliner menu under windows and select the camera and open the attributes.

Then open environment and change the BG color "Default is black"...and you can try load the environment map you have on that and it should render as the camera bg.

Unless you resolved this yourself already.

Jeremy Lindstrom

You'll have an issue though if you move your camera at all, since the image will be tied to the camera's movement.

Illusions

I'm wondering why now that you can't just put a plane, or sphere in the background, and link the image to that. Just turn off cast shadows/receive shadows in its renderstats.

Jeremy Lindstrom

yup could do that and also add light linking to the image only, if it gets too dark or too light.