Animation - Camera path indoor to outdoor Lighting with Arnold in 3DS Max - Physical Sky Environment

[matthew.brophy]

Hi everyone, can someone shoot me some ideas as to how to overcome a lighting problem I have when dollying a physical based camera in 3ds max using Arnold with a physical sky in the environment shader.

Task: Camera path is to then go from inside a construction site cabin to outside of the cabin to focus on happenings on site.

Lighting within inside the cabin doesn't work with a physical sky in the environment slot turned. I could split the animation from when the camera passes the door frame however this would cause issues on frame blending in post.. 

This isn't real-time rendering so I don't know if this is the best place to ask however there's lots of experts on these forums with a wealth of experience who may have an idea..

I have dropped the Elevation to 25 and the Azimuth to 150. I have created an Arnold spotlight looking in through the windows...

The cheat would be to remove the ceiling of the cabin which isn't in shot but Id like to learn to see if this is possible without cheating.

Thanks

Matthew

[oliver · Accepted solution]

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@matthew.brophy wrote:

Lighting within inside the cabin doesn't work with a physical sky in the environment slot turned.

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Your assumption is incorrect, there are several ways to do that. In your scene I see two possible ways to react to the difference of light-intensity between indoor&outdoor: RayDepth & CameraExposure.
RayDepth: increasing the Diffuse RayDepth in the RenderSettings will allow the light to bounce inside the cabin more often hence lighting it better. This is much more accurate but also more render-intensive.
Camera-Exposure: like in real-world cameras you can react to changing lighting conditions with changing (=animating) exposure-values.
Hope this helps.

[madsd]

Use the Arnold Imager nodes.

They are grading nodes, for the ARV framebuffer.
Doing typical archviz base lightning is easy with Arnold in general, and if you want it to go very fast, you should use a couple of tricks.

The Imager node you want to massage first off, is the Tonemap node, and you want to drop the Reinhard Highlights to 0.0 first off, then work in your general gamma and exposure, then if there is room, lift the Reinhard highlights.
This specific effect lowers the exposure on overexposed areas, such as exteriors, and you will have a big difference inside and outside, unless you make sure you use lamps that are capable of shrinking this effect down, and massage the Arnold render view post grading tools.

The image here renders in 25 seconds ~ zero noise. Using area lamps and a directional instead of the physical sky.
It is orders of magnitudes faster and much easier to trim up against perfect settings for speed both on the CPU and the GPU.

Now if you want an unrealistic artistic expression, like the same kind of light inside as outside, you need to use area lights as a substritude for skylight and use a single directional lamp, this is also the fastest to render, but just bear in mind setting the exterior and interior to identical or near identical exposure is highly unrealistic so it wont feel natural.

You have to massage the sweetspot.

[matthew.brophy]

Thanks for your reply ill have a go at tone map which I haven't used before. Very helpful!

Its for an animation where the camera runs from inside the cabin, to outside.. I'm not after photo realism as its for a safe system animation in construction for training - however I am really appreciative of your response and thankyou. I will give this a go in some stills.

[matthew.brophy]

Hi, thankyou for your quick response, Ill give this trick with camera exposure a go and keyframe the exposure and camera. Thanks