Hello and thanks for your time,
I’d like to use the Physical Sky in my scene to obtain the correct lighting in the scene, but I do not want to render the acutal blue sky, just the scene with all the GI and reflections of Physical Sky.

Is there a Matte or Exclusion I can somehow place in the Physical Sky so that MR renders without the sky in the background and with an alpha to block it out too??
K

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If your goal is to have the sky “missing” from the rendered frame, save the frame as a PNG file.

3ds Max 9 thru 2013
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3ds Max 2012 Certified Professional Models to Motion

I think you can just uncheck the “use map” button as a background in the environment and effects dialog under “render” and it will still use the lighting.

I think you can just uncheck the “use map” button as a background in the environment and effects dialog under “render” and it will still use the lighting.

It will still use the lighting, that comes from the skylight in the daylight system, but you will lose the reflections from the environment, so for example a chrome object will reflect a black sky.

Use the “Environment/Background Switcher”, plug the Physical Sky into the Environment slot. For the Background slot use the colour you want, or plug in another BG map if you want to. Then as Doughboy says, save to a format with an alpha channel.

i would do what Samab says. png file with alpha enabled will get rid of the background. plus, with the background switcher you can achive some really nice reflections on metal objects that may not seem scene correct but still look beter than the gradient reflection that the mr sky has.

it would be nice if Autodesk would implement a procedural cloud preset for the mr sky. it would save the hassles of of mapping a static cloud map in the sky.

3ds Max Design 2010/11/12, 64bit, Boxx technologies, dual quad core 2.8, nvidia quadro 4000, 20GB Ram, use mental ray for rendering, windows XP pro 64bit