Well not all about them, but this should help point you in the right direction.
I’ve had a few people ask about the construction of shadows. I’ll talk about two types here and I’ll be up front here – I won’t cover every situation or even more complex scenarios, but the principles here will help you construct fairly accurate and believable shadows when sketching.
Shadows occur when an object obstructs the path of light. The shape of the shadow is determined by the shape of an object and is a direct result of light passing the edge of the object casting the shadow. Typically, there are two types of shadow that I sketch – Sunlight, and Drop Shadows. Drop shadows are shadows cast directly below on a plane by the object as seen below
Since drop shadows are simple enough, I’ll cover another kind here – the Artificial Light Shadow.
Before we continue, if you’re into the more technical of explanations, you can check out this website.
Natural Light Shadow
Technically speaking, there is no difference between an artificial light source and a sunlight source. The sun is so far away that the rays emanating from that light source though, converging at the source, appear parallel on earth. Check out the photo below. Fortunately, I had a sunny day in San Francisco and a chance to take some good photos.
See more after the break…
Basically, lines are projected from each corner of the top surface as well as the corresponding corners of the bottom face of the cube. The intersection points are connected and voila! We have a shadow! Simple enough right?
Artificial Light Shadow
Artificial light shadows are basically the same as a natural light shadow, however, our light source is alot closer to us – millions of miles closer to us. Check out the example shown in this photo –
With an artificial light source, lines are projected from the center of the point light source (in this case, a lightbulb) as well as the base of that light source as it intersects the plane on which the object rests.
Since the lines projected aren’t parallel as with the sunlight example, the shadow that is projected will appear to get wider, the further away from the object you go. In the above example, the shadow spreads out wider to the right of the picture.
Check out the video below as well as the sketches to see how to construct simple shadows on paper.
Well, hope this covers some simple shadow tips. Try applying this to some more complex shapes and experiment. As always, experiment and have fun, and if you have any questions, contact us in the forums or post your work for critique.