Thanks go out to Ryan Barber for this tutorial. See more of his work at http://www.behance.net/rbarber
The first phase involves tracing a series of triangles on top of a photograph, in Adobe Illustrator. Create a new file at 6.66 inches x 10 inches. Select File>Place and find a start image to work from. In this case we have used a Dreamstime model (#18986388). Once the file has been placed into Illustrator, lock the image.
You can lock the image in one of two ways. Either lock the layer in the Layers palette or highlight the image and then press Cmd/Ctrl+2. All your work will be laid directly on top of this image. Once you are done with the illustration, you won’t need the base image any longer.
Now that your image is locked you are ready to apply the Pen tool, so activate this now. Make the Fill colour transparent and set the Stroke colour to something that will be easily visible when laid on top of the image. In this case, a bright magenta will suffice.
The next step is to set up the weight of our Pen tool’s stroke. We don’t need this to be too thick as, essentially, our marks will only work as a guide. In the Stroke palette, set a thickness of 0.02 inches – this will keep the illustration thin enough for us to still be able to see most of the photograph underneath. If your view of the photograph’s details is obstructed then it will be more difficult to map the grid.
It is now time to start mapping out a series of adjacent triangles on top of the base photo. No other shapes should be used here, and each triangle should roughly cover one solid area of colour. Try squinting when you’re looking at the start image – this will help you to separate out the different areas of colour more easily. Draw the first triangle by clicking somewhere at the top of the model’s hair, and then completing a triangle that roughly covers that section of hair.
Select the first triangle and then copy it by pressing Cmd/Ctrl+C. Paste it on top of itself by pressing Cmd/Ctrl+F. We want this new triangle to become adjacent to the first triangle. In other words, it will share only one side with the first triangle. It’s important to generate new triangles by copying them directly from the ones that have been created before; if we don’t use the copy/paste method, our grid will have holes and cracks in between the shapes.
Activate the Direct Selection tool by pressing the A key. Our selection tool’s cursor will change in colour from black to white. Click on the top triangle’s uppermost anchor point. Drag that anchor point down and slightly to the right, as you can see in our example. The second triangle will now only share one common side with the first triangle. We’ll keep on repeating this process of copying, pasting and dragging one anchor point at a time until the photograph is covered with triangles.
Copy the second triangle by pressing Cmd/Ctrl+C. Paste it on top of itself, as you did before, by pressing Cmd/Ctrl+F. Apply the Direct Selection tool to this third triangle’s top anchor point and then drag it down as shown. Remember to keep an eye out for the edges and colour changes as you work, since accuracy at the drawing stage will really pay off. The third triangle should now only share one side with the second triangle. We’re now starting to get the hang of this sort of application.
Most triangles will share one common side with another triangle, but some triangles will only share a portion of another triangle’s side. In this step, we’ll use the Add and Subtract Anchor Point tools to make precise edits to the length of one of our triangle’s sides. This will provide much more flexibility in how we lay our grid out.
It’s really easy to just make all the triangles the same size because it speeds up the process. However, resist the temptation to rush through the drawing stage. Really focus on varying the sizes and shapes of the triangles. The more we vary the locations of our shapes, the more unique our illustration becomes. The reference images in the screenshot, for example, show two circular shapes; one is much more interesting than the other. This is just a general guide on how to approach mapping the grid.
You’ve got your grid ready – now it’s time for the polygons. First, grab the Eyedropper tool and sample a dark skin tone from underneath the triangle we plan to colour first (shown in the next screenshot). Add that colour to the Swatches palette and the New Swatch window will then appear. If you’re planning to print an illustration then set this to CMYK mode. If you’re using an illustration online then set this to RGB mode instead. Apply the Direct Selection to the triangle and click on the new swatch.
Press I to activate the Eyedropper. Click anywhere to sample a respective colour. In the reference image, the red triangle has a light tan colour and fades to a darker brown colour. Sample the tan area to update the Fill colour in the Toolbar. Drag that Fill colour to the Swatches palette, then repeat for the darker brown colour. Drag both swatches into your Gradient palette, delete the default black and white swatches, then adjust the gradient slider so the tan and brown colours are at opposite ends of the slider.
To be continued…