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  • Teddy Gage

Simple Lighting Study - A Redshift breakdown



So I happened to find this book "The Photograph as Contemporary Art" sitting abandoned in the hallway at work and as I was flipping through it I stopped on a photograph that struck me as a really awesome study of light and form. The work was by the photographer James Casabere and the photo was "Pink Hallway #3." I thought it would be a good personal challenge to recreate it entirely in-engine in C4D. Midway through the project I read on about this and learned he had created the originals as a tiny prop and photographed it from the inside. There was something very appropriate to me about recreating this hand-made model from scratch in a render. Original photo below (credit to James Casabere)



I started out my professional life as a photographer, so I approached this the same way I'd approach a real-life shoot. Reconstruct the shadow angles to figure out the original light paths, and then cheat the hell out of it.

So this project was approached as a no-comp / no grading project to simulate the "black box" of Casabere's approach. Everything is tweaked in materials and using the photographic exposure mode on the camera, since that made sense to me on this "shoot". Simplicity was key to breaking down the original, so the lighting setup was equally simple - 3 spotlights and an area light. Lack of HDRI meant less troubleshooting and more control.

As such, the camera details were as follows:


Part of the fun was trying to eyeball everything - modeling details, camera lens length, exposure and texturing.

I did all the modeling from scratch - by itself wasn't a huge challenge, other than the cylindrical cut-ins of the vaulted ceiling, which I started by messing up a bunch of boolean methods. Essentially that's how I finished it, but with a bunch of trial and error to figure out the right topology and edges to cut and sew.


I don't think there's a ton that's interesting to be said about the modeling, other than keeping everything procedural allowed me to easily make minute tweaks to get it closer and closer to the original. And gave me an appreciate for carpenters who make perfectly fitted moulding and fixed corners. I will say the Mesh Boolean plugin was extremely helpful.

Redshift really excelled here when trying to do a photoreal recreation of a real life scene: being able to sculpt the light and shadows by including / excluding objects was immensely helpful and would have been nearly impossible in an unbiased engine.

Some folks might notice a lack of caustics here but I was trying to be as close to the original as possible - which had no visible caustics.

I learned a lot about Redshift, mainly how to clean up interiors, but I'm not giving away all the secrets. A few bullets I'd note about this scene:

- Materials created in Substance Designer, which has a great workflow with Redshift now. Just drag and drop from your Redshift Asset Manager in the Pipeline menu!

- 3 spotlights, a point light and 1 area light

- No HDRI or Env = faster, cleaner renders

- Brute force + IRC

- 32 min samples, 512 max samples

- Sampling overrides set to 4096

- 1096 Brute force rays

- Render size is 3200 x 3840 and on 4x 1080tis render time was 13 minutes. This is due to the extremely high sampling rates on the Irradiance point cloud. Most folks set it and forget it

- IRC set to 16 screen radius (crashed under 16

- samples per pixel was 32 and retrace threshold was 2

"..I hope to draw attention to the artificiality of what we believe is actual and true and how we construct our subjective responses to life"

"I am trying to capture the essential artificiality of a photograph by combing photography with sculpture"

-James Casabere

The above quote struck me, since that's what we do in 3D every day.

Questions or comments feel free to contact me VFX@shotgunpost.com


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