Cast shadow | Diverging source light from projectors |Tip112

We saw at the TIP 109 How to draw Cast Shadow using PARALLEL source light (such as the sun). Today let’s see more about DIVERGING source light (such as 1 or multiple projectors).

You are free to use any of these 2 techniques.
To illustrate both techniques, let’s consider the volumes in the videos to be something you could hold in your hand. Basically, I consider that the “Parallel source light” would come from a (huge) wide source of light such as the sun. The “Diverging source light” would fit better for small lights such as projectors.

Note that it’s all about scale. If you draw an entire city with high buildings, you may want to use the Diverging source light. It may give a more “dramatic” result.

At the end it’s up to you to choose the graphic impact you want to give to your sketch.
cast shadow diverging source light with 1 projector
Cast shadow with 1 projector.

cast shadow diverging source light with 2 projectors
Cast shadow with 2 projectors

cast shadow diverging source light projectorsCast shadow with a closer projector to the volume.

I recommend you guys to try to draw a few and test a minimum of 5 different source of lights. Take a pen and let me know how it goes in the comments below !

Note: Do not train using any ruler to trace the straight lines. It’s a good habit to take from the start. If needed, you can click here to get a tutorial on how to draw straight lines without ruler.

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About The Author


Hello! My name is Chou-Tac. I am a Product Designer from France. If the sketching methods I’ve acquired aid me in my life and in my industrial design career, I believe that they can also help you reach your design goal as a student or professional. My aim to help you all along with your design projects and journey. Anytime, feel free to leave a comment in the blog or send me an email at : )


  • hal9000

    Reply Reply August 11, 2015

    your cylinder does my head in,I thought the light source had to be shown at a right angle to the floor but that just looks like you have drawn the light on the rail at the top, but at the front of the cylinder and then connected it to the floor at the back. 🙂

  • Noha

    Reply Reply March 29, 2015

    i’ve never seen someone teach shadows easier than this 😀 … thanks alot for sharing this with us ^_^

    • Chou-Tac

      Reply Reply March 29, 2015

      Ahah, when I created this “technique of projector rails”, I also wished people taught me like that too lol.

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