Interior lighting with Maya Physical Sun and Sky


I am putting together a video tour of a 15th century castle structure. The tour takes place on the outside as well as the inside. I am still new to the Physical Sun and Sky(S&S) and have run into some problems. Once I set up the S&S for the environment all of the lights I placed for the interior are instantly bypassed and do not work. (Fireplace and candles due to it being in the morning around 10 am for the video) I tried using an area light as a portal light, however, due to the particular placement of the few windows and the sun the inside is still too dim for a video tour of the structure. I was wondering if there is any alternative to help with this problem. Can I somehow make the interior lights visible along with the Indirect Lighting of the Physical Sun and Sky?

I am using a MEL script to allow for the mia_exposure_photographic tone mapping shader rather the mia_exposure_simple shader in the S&S.
Also using Maya 2010
Mental Ray
Indirect Lighting (Final Gathering and GI)
Physical Sun and Sky w/ MEL script stated above

Thank you for taking the time to read and hopefully help.


Double check that you use the portal lights correctly (enable lightshape and check your mr tab settings).

If you don’t use portal lights, you will need to crank up the sun’s light energy way too much in order to have indoor illumination - and this will render the indoor lights totally useless.

Portal light is a light multiplier to match indoor light’s and outdoor illumination energy settings - you must use them most of the time.


I imagine you’re going to want a light setup for your outside shots and then a similar but different one for your inside shots. Or key off certain lights when viewing from the outside. I recently did some outside-to-inside arch/viz work, I’ll look it up again and see how I made the Portal Lights work during the transition.

You’re going to need Portal Lights for interior rendering, with the Sun/Sky. They acts as a “FG concentrator” for Final Gather. The basic premise is that without them, the Sun/Sky Directional Light node shoots FG rays all over of course, and only a few of them will actually make it through your windows or openings. The Portal Lights tell the Sun/Sky where to shoot the FG rays, basically, which gives you much more realistic and even lighting without wasting FG ray calculations on outside areas which aren’t even visible to the camera.


Awesome, thank you very much fellas I really appreciate the response.

As far as I know I setup the portal lights correctly. It seemed to work and they looked good, but for the purposes of how the scene is set up (Which I have no control over due to the project leader having certain specifications) they will not be bright enough to display certain items in the scene and honestly add an ungodly amount to the render times. Unfortunately there are only two windows that they can shine through and they are located on the opposing side of the sun’s direct beams.
So far as a quick solution I have just rendered the frames into the transition for the Sun and Sky scene and did the same for the interior scene. From there I have tried photoshopping the images together where the transition occurs.

I made my way through some tutorials about the S&S prior to my original posting and in one specific written tutorial by autodesk they had a separate light in the scene for a lamp. During the process of checking the S&S they had the light off, but all of a sudden they turned it on and literally do not say anything else but “Let’s turn the light on for the lamp.” It seemed as though the S&S feature did not render the interior light useless. They could have done something completely different to make that interior lamp light, but to myself it seemed as though they effortlessly “turned” it on. Is that even possible to do with the S&S being utilized?


Sure, that’s possible. Really easy. All my interior lights consist of an area light (often set to sphere) and then a physical geometry lightbulb, which has a mia_mat_x with a Light_Surface shader in the Additional Color slot, which is often attached to that specific light. Then you have three separate controls - one light control, one shader control, and one glow control. Each of these have their own subcontrols too, obviously. The light bulb shader could be clear glass or foggy, frosted soft light bulb glass, for example.

But you group them all together and then set them on a Layer, “CanLights” or “VanityLights” for example, in my arch/viz scenes, and then it’s a one-click solution to turn them on or off. Same as hiding the light, the bulb, or the group.

Interior and exterior lights work fine with the Sun/Sky. I use additional area lights in all of my scenes, really. They match up to the physical geometry as called for by the client and the design, of course - no need to fake lights if you’re going for realism, anymore.


To clarify, to turn “Off” a light, simply select it and press Ctrl-h for “Hide”. Or Ctrl-Shift-h for “Unhide”. You could alternatively use Quick Selection sets for your lights to hide and unhide them, but setting them to different Visibility Layers is even easier.


This just sounds like an exposure problem to me. Did you try adjusting the exposure for the interior shots? Its a while since I used mia_exposure_photographic, but there are a bunch of attributes you can adjust there to mimic the exposure settings on a camera.



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