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Lighting Design:Contrast - recommended reading

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#1

If you have access to Game Developer Magazine for April 2005, there is a very smart, very informative column by Steve Theodore explaining fundamental principles on Lighting Design in 3d rendering and real-time game engines.

It’s all about the importance of CONTRAST to human perception… and how an artist must calibrate relative contrast levels in renderings - using the same 256 gray levels to represent candle-lit environments and landscapes bathed in blazing sunlight - modulating light-to-dark ratios to represent every possible lighting situation. This was a lesson the old masters had to learn and it’s something contemporary artists must also understand to manage convincing renders.

Again, the Magazine: Game Developer, April 2005
the Article/column: (Pixel Pusher) Lighting Design: Contrast
the author: Steve Theodore

This is part two of his series on Color.

Several links he mentions at the end of the article:

Paul Debevec’s webpage

HDRShop - High Dynamic Range Image Processing and Manipulation

Watercolorist Bruce McEvoy (everything you ever wanted to know about watercolor painting theory)

#2

Excellent, thanks for the heads up!!

#3

do you have a digital copy of this or can get one??
it would be greatly appreciated! thanks!

#4

Pilou

#5

Hi S.C.

I’ve googled the article title and found nothing except a mention of the article in the April issue at the Game Developer site.

FYI, some of the article is just a rehash of TONAL VALUE DISCUSSION on the Bruce McEvoy site.

A clip from the article:

… we’re physiologically primed to accept monitor images or printed pictures as ‘real’ even when they cluster in a very narrow range of absolute intensities.

This might seem like just interesting trivia, but in fact it’s critical for effective contrast management. Our ability to recalibrate teaches us that the distribution of contrast in the image is an indication of the strength of the light source(s).

This is actually something of a paradox. Bathing the scene with intense light ought to mean that every surface is reflecting more back to the eye, and so you might expect the image to wash out. Our biological contrast filter, though, has to stretch our limited visual palette to cover the intense highlights as well as the somewhat elevated ambient colors. Even though the low tones really are brighter in absolute terms, that increase is insignificant against the vastly expanded scale of intensities. Tones in the low end of the scale will seem darker even as they reflect more. For obvious reasons, therefore, we instinctively see contrast as a proxy for the intensity of light in a scene. Sharp contrasts suggest intense light sources while an even distribution of mid-tones implies a softer light…

The article consists more of enlightened observations (excuse the pun) than in-depth lighting solutions or “contrast secrets” in image making.

Sven

#6

Thanks Sven!

For anybody interested in making their own HDR files (or any LDR image panaorama manipulation) I recommend HDRShop. It is free and works well, though sadly, it is only for Windows. For Mac there is Photosphere and also Photomatix .

If you’ve a digital camera it is not difficult to make a 360 degree panorama. All you need is a mirrored ball such as a Christmas bauble. At a pinch one shot will produce a passable panorama; to get rid of the photographer and the distortion you need a second photo at 90 degrees to the first. You can put them together in HDRShop and fake the HDRI by simply outputting as a .hdr file - this can be used in any software that supports image-based lighting with .hdr files.

#7

Many thanks, this also might be of some use.
Site provides hdri images to download for free.

Light Probe Image Gallery

#8

Just wanted to add this adress for people interested in spherical panoramas and HDRI:

short introdution and explanation about HDRI

To see some Render-Examples, go to:

Render Gallery

or have a look at the following Panorama-gallerys (PDF):

Gallery 1
Gallery 2
Gallery 3
Gallery 4
Gallery 5
Gallery 6

It really would be great if Zbrush would support real HighDynamicRange Imagery in the next version. The already integrated “HDR”-functionality is cool but it is not equal to the behavior of real HDR-Imagery.

As main profession, I´m working as a freelance-modelling artist myself (portfolio), using Zbrush a lot in my daily work and I´m sure this would be a big pro, when it comes to the decision wether to use Z for the final output or not.

Kind Regards,

Jan Häusle