This tutorial will show the intermediate-to-advanced Adobe Illustrator artist how to make a realistic military style cap icon using predominately gradients, blends, and the Gradient Mesh Tool. We'll be using a photo reference to base this illustration on, though utilizing creative judgement throughout the process.
Final Image Preview
Below is the final design we will be working towards.
Start by taking a photograph of a cap that has a nice angle. Usually, the resulting illustration is only as interesting as the original photo. Do consider lighting when you take the photo. Good lighting will ensure that you know where to draw shadows and highlights when doing the illustration.
You'll be able to focus on workmanship and not trying to visualize where shadows and highlights should go. Although, you can compensate for bad lighting if the conditions of the photo don't allow for nice lighting. This photo is not the best, but I will improvise and exaggerate the shadows and highlights that are visible.
Put the cap photo on it's own layer and lock that layer. Throughout this tutorial I will be using multiple layers to make it easy to lock items when not in use. I will not be pointing out when I use a subsequent new layer.
Use the Pen Tool (P) to trace each section of the hat. Do not trace the entire outline of the hat all at once. Tracing sections will afford you the opportunity to control how the gradient mesh works within each area more precisely. Use a bright color and set the strokes thickness to about .5 to make it easy to see what you are doing.
Observe how each piece of the cap is its own shape. Also, do not worry about tracing each and every detail of the photo. Use creative discretion when determining what to include and what to leave out. Details like the hardware on the front of the cap would not reproduce well in the resulting icon since it is so detailed.
Fill in the sections of the cap with a base color. The top of the cap uses a medium green color. Since I will be adding shadows and highlights, I always think ahead and pick a color that is not too dark as to impede with the shadows I will add later. To clarify, if I used a darker green color, the shadows would not add much more depth. So, think about how you want the final piece to look before you get started.
Since the cap is broken up into multiple sections I was able to easily and more precisely predict how the mesh points would be placed. When placing mesh points I made sure to place as few as possible and not too close in proximity to each other, except near the lower edge of the brim, as highlighted below. I placed two points very close in this instance because I know that I want a sharp change, from one color to a lighter color.
When placing mesh points it is usually easier to place the first mesh point near the center of the object. You should only need to place about five or six points to achieve the look below. Access the Mesh Tool by pressing (U).
The most effective way to define shadow and highlight colors is to add them to your Swatches Palette before you need to use them. This also will ensure that your colors are consistent. For example, if you are using a light green color on the left edge of the hat you will probably want the same color on the right edge. It's better to have swatches defined, than to try and guess what color you used, or arbitrarily adjusting the sliders.
Using the Direct Selection Tool (A) select the points that you would like to add shadows to. Select multiple points by dragging over all the points, or by clicking each point one at a time while holding down shift. Once you have the points selected simply click on the darker color in your Swatches Palette to apply it.
Although you have predefined swatches in your Swatches Palette you may want to make a special color at some point. Using the Direct Selection Tool select the point that you'd like to change the color of, then go to the Color Palette, click the small triangle in the upper-right corner, and select HSB. HSB will allow the color of the point to change to lighter and darker tones of the color. If you simply want the color to either be lighter or darker, change the B slider, as shown below.
Add mesh points to the bottom of the cap and adjust their color too. You can move individual mesh points around if you are not satisfied with their original position. To move the mesh points select them using the Direct Selection Tool and move them into position.
The bottom of the cap is under the shadow of the top of the cap. If you have discovered that you need to drastically adjust the darkness of any portion of the cap you can select individual points or the entire object and change it's overall color. To change several mesh points colors at once go to Edit > Adjust Color Balance. Give all the input areas the same value to either lighten or darken the colors.
Notice how the shadows are much more dramatic than those in the original photograph. As I mentioned earlier, if the photo is not properly lit you will need to fabricate where the shadows should go as you're making the icon.
We'll give the brim of the hat a slight highlight by first drawing a shape that follows the curve of the cap. Blur the shape by going to Effect > Blur > Gaussian Blur...
Instead of adding every single detail using the gradient mesh, you can add other shadows in the same manner that we used for the previous step.
When using black you should use a rich black color, not a grayscale black. Rich black creates a darker black and uses red, green and blue at 0%. Greyscale black is not bad to use, it is just not completely black. The swatches that Illustrator automatically adds to your document are greyscale black, except for the swatch indicated. If, for example, you were to make a gradient using the greyscale black swatches, it would never look all the way black.
You'll notice that the bill of the cap uses Illustrators greyscale black at this point. Go ahead and make it a rich black and give the different elements of the cap subtle gradients.
You can give each of the elements more depth by giving them an inner glow. To apply an inner glow go to Effect > Stylize > Inner Glow... Select a dark color and set the Mode to Multiply.
Draw a shape over the bill that will become the reflection.
Give each piece of the bill a gradient. Experiment with Radial and Linear gradients, using them where they work best.
Achieve more depth by drawing a black shape that follows the curve of the band above the bill and blurring it by going to Effect > Blur > Gaussian Blur.
Draw highlights using the Pen Tool on strategic areas of the caps band. You do not need to highlight every area. The other highlights are implied. Implied highlights give the icon more interest.
Add highlights to the other areas too.
Give the large highlight on the bill of the cap an inner glow (that functions as a shadow) by going to Effect > Stylize > Inner Glow... as achieved in Step 16.
There are two different shadows that are used to complete the illustration. The first shadow uses to shapes that are drawn using the Pencil Tool (N.) For the purposes of demonstrating how to achieve the effect, I have turned off the cap layers. When you draw your shapes, it will be easier to draw the shadow on its own layer with the other layers visible.
Draw one shape and give it a dark fill using rich black. Draw a second larger shape and give it a completely white fill. Note that my larger shape uses a light grey color. This is so you can see that there is in fact a shape drawn.
Select both shapes and go to Object > Blend > Make. Illustrator will apply the last settings used. If you want to change how many steps are used go to Object > Blend > Blend Options.
The second shadow is used under the bill of the cap. Create this shadow by drawing a half circle. Blur the shadow by going to Effect > Blur > Gaussian Blur.
Set the Transparency of both shadows to Multiply, so they blend together nicely, if they overlap. You can also adjust their opacity if need be.
Here is the finished military cap icon.