Light can provide a wonderful source of balanced colour in 3-D rendering.

A totally monochromatic scene, lit by six lights in a circle.

The same scene and the same lighting, except now the lights are coloured. Six equal steps of the spectrum where used, red, yellow, green, cyan, blue and magenta. The huge range of hues that results is determined by the mix at any given distance from all of the lights, since the intensity of a light falls off on the square of the distance.
The layout that was rendered without the pillars showing. Since the walls of the room are mirrored, the size of the room looks enormous.
The same set, but with the pillars visible.


While the standard Windows colour picker uses values from 0 to 255 with RGB values, it uses 0 to 240 with Hue, Saturation and Luminance. Hue is actually a colour circle beginning with red at 0 with a maximum of 239. If 240 existed, it would be red - just as 0 is red.

This makes it very easy to choose equal spacing between the colours of light. In the first row, you see the primary colours of light, red, green and blue. Their hue values are 0, 80 and 160. An object at exactly the same distance from each will be in white light. Red+green+blue=white!

If more lights are required and a nicely colour balanced rendering is wanted, different intervals are needed. Four light require an interval of 60 giving 0, 60, 120 and 180.

Five use a difference of 48 for 0, 48, 96, 144 and 192.

Six use the primary colours red, green and blue and add the secondary colours, yellow, cyan and magenta - 0, 40, 80, 120, 160, 200.

Seven use a difference of roughly 34, so rounded off the sequence is 0, 34, 69, 103, 137, 171, 206.

Eight use a difference of 30 for 0, 30, 60, 90, 120, 150, 180, 210.

For more lights, divide 240 by the number of lights and begin the series at zero. It is not vital that you begin with pure red, but it certainly makes calculating the hue of each light a whole lot easier than if you started with a hue of say 17.

Hue - Saturation - Luminance.

Saturation is 0 for no saturation - white, grey or black and 240 for maximum saturation - pure colour. Luminance also runs from 0 to 240. Zero is always black, no matter how hue and saturation is set and 240 is always white as well. When dealing with light, leave luminance at 120 for predictable results.

When dealing with object colour, thinking in hue saturation and luminance is very handy for visualization. Knowing that the primary and secondary colours are hues 0, 40, 80, 120, 160, 200, one can easily guess a close value for something in between. Luminance - also referred to as "lightness" provides a middle grey at 120, black at zero and white at 240, again making it easy to find exactly the tone you want. A high value for saturation provides a powerful garishness to objects, while a low value provides pastels.

In the two renderings at the top of the page, the first is just luminance without either hue or saturation.

Learning to think in HSL makes visualizing colour in either 2-D or 3-D art much more efficient. Trying to remember RGB values so one can use the same colour in the next picture is an exercise in frustration.

There is a specific page on Hue - Saturation - Luminance

©2007 Larry N.Bolch