In this tutorial I will be showing you some basic techniques on how to create and set up realistic and believable lighting and shadows. This will be our reference image.

1. The first thing that needs to be done before you start on your illustration is to determine the light source. This should either be decided in the sketch or determined by the photo you are working from. In the example that I am using to show you, the main light source is the sun and the secondary light source is the cell phone screen.

2. The next step is to setup basic directions for shadow and light. Here are some basics to remember.

*Where are the light values? Look for the lightest areas on the object. The very brightest of the lightest  values are called highlights.
*Where are the dark values? Dark values often reveal the sections of the object that are in shadow. By  locating shadows, you can usually identify the light source.
*Where is the cast shadow? The section of the cast shadow closest to the object is usually the darkest value in a drawing. By locating an object’s cast shadow, you can easily discover the direction from which the light source originates.

The sun light is coming from a little bit above the middle left near the top angling down, so the shadows should be heading in the same direction as the light, towards the bottom and to the right. Also the lower the light source is towards the horizon line, the longer the cast shadow will be. And the longer a cast shadow is, the more it will blur at the end.

3. After that, find out the intensity of the light, shadows and the reflections. The brighter and more intense the light source is, the more intense the highlights, shadows, and reflections, will be.
Each time you reposition the light source and intensity, identify the following:
*The shadows on the object (dark values)
*The brightest areas (the highlights)
*The light values (areas closer to the light source or not in shadow)
*The cast shadow (the darkest values)

4. I will show an example on the man climbing. These are the elements to look for. Notice that there are two different highlights coming from two different light sources. From the sun on his elbow and from the screen on his face and hand.

5. Now I will show you basic tips on how to paint on shadows and highlights.The first thing you want to do is select the object your painting by holding Ctrl and clicking the objects layer icon, that will load the selection.

Next make a new layer above your objects layer and name it shadow. On the shadow layer while your object is still selected paint some shadows using a very soft brush at low opacity with a dark grey or black. Set that layer to hard light and lower the opacity until it looks right in relation to the light.

Next create another layer and name it highlights. In the same way as the shadows paint on some highlights were the light would be hitting the object. Use either white or a lighter color of your light source. Set this layer to screen and lower the opacity. Move this layer above the shadows.

6. The last step is the cast shadows. I’m using the Phone as the example. To do this select the object as in step five and on another layer fill it with a dark gray or black.

Hit Ctrl+T and transform the shape so that it  is heading in the direction away from the light source.

Apply a Gaussian blur of around 3.5, set the layer blending mode to hard light, and lower the opacity to around 55%. Place this below your object layer.

I used this technique for both the car and the shovel. For the clouds it’s the same technique as the man climbing, painting the shadows underneath and intensifying the highlights on the tops.

That’s it! I hope you learned some helpful techniques on lighting and shadows in a digital illustration.

This entry was posted on Thursday, April 30th, 2009 at 12:23 pm and is filed under Graphic Design, Tips. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.