In this fun beginner's tutorial you'll learn how to get sophisticated results using a few simple elements and effects. The design is based on M-Audio's discontinued Trigger Finger Drum Pad Control Surface (see inset). Let's get started!
Create a new CMYK document, 10 inches (720 points/pixels) square. You can work in RGB and any other unit of measurement if you prefer. Draw a square the same size as the artboard and fill it with a medium gray. This is simply a placeholder for now, so you can more easily see the highlights and shadows you'll be creating. Lock this shape, or put it on its own locked layer.
Using the Rectangle tool (M), click once on the artboard. Enter 1" (72 points/pixels) for both the width and height. With the square selected, go to Effect > Stylize > Round Corners. Enter a Radius of 5 points. Then go to Object > Expand Appearance.
Select the rounded square and go to Object > Path > Offset Path. Enter 2 points. With the new path still selected, offset it by 1 point. You should have three paths total.
Select the outer-most path and fill it with a linear gradient that goes from 7% black to 30% black. Choose the Gradient tool (G) and drag the gradient at an angle, as in the image below.
Fill the middle shape with a rich black, using the CMYK breakdown as shown. If you're working in RGB, the value for all three colors is 0.
Now fill the innermost shape with a radial gradient that goes from 80% to 100% black. Drag with the Gradient tool, positioning the center of the gradient at the top left corner of the shape. This will give the object a subtle shine and dimension.
Copy the center object, then paste it in front, either via the Edit menu, or by using the keyboard shortcut, Command-F. Now Right-click on the copy and choose Select > Next Object Below. Fill this object with 60% black, then nudge it up and over by pressing the left and up arrow keys. Adjust this shape manually if necessary to form a thin highlight. Select these four objects and group them. This is the main pad shape.
Choose the Polygon tool (click and hold the Rectangle tool to reveal it) and click once on the artboard. Enter 36 points and 6 sides in the Options box. The polygon should have a fill of light gray (about 15% black) and a 1-point blue stroke. Round the corners as you did before, under the Effects menu.
Center-align the polygon with the pad group, using the Align panel or the Control panel (tip: make sure "Align to Selection" is checked as the method). Send the polygon to the back, then position it so only its lower third is showing. Once it's in place, group it together with the pad group.
Select the group and press the Return key. In the Move dialog box that appears, enter 1.25" in the Horizontal field and 0 in the Vertical. Click Copy. Now press Command + D twice to make two more copies, for a total of four.
Select all four groups and press Return again. This time, enter 1.5" in the Vertical field and 0 in the Horizontal, and click Copy. As before, press Command + D twice. You will now have a grid of 16 pads.
Now for the sliders. Draw a rectangle approximately .5" x 2.25". Click once on the Artboard with the Ellipse tool (L) and enter .5" in each field to create a circle.
Align the circle and the rectangle as shown. It helps to turn on Smart Guides (under the View menu) to position it precisely. Once the circle is positioned, select it and the rectangle, then press the Unite icon on the Pathfinder panel to merge the two shapes.
Offset the merged path by -6 points. Now take the Line Segment tool (\) and draw two short lines to form a miter at each corner. Smart Guides will help with the placement. View in Outline mode to make sure the lines are positioned precisely.
Select the slider shapes and the angled lines and click Divide in the Pathfinder. Select any excess paths with the Direct Selection tool (A) and delete.
Fill the outermost shape with a linear gradient, going from left to right (set the Stroke to None). Fill the inside shape with another gradient, dragging it at an angle. Then fill the bottom shape, with a light gray, about 10%. You can see how a few simple gradients gives the illusion of a recessed, semi-glossy object.
Draw a tall, thin rectangle for the cut-out in the center. Make a thin highlight as you did with the pads. Group and then center with the "recessed" shape.
For the slider knobs, draw a rectangle and round the corners as before, only make the roundness value greater. Expand the appearance, then fill it with a subtle, 90%-to-100% black linear gradient. Offset this shape, fill the offset with black and nudge it down a bit with the Down Arrow key.
Draw two thin rectangles the same width as the top shape, and fill them with gradients as in the image below. Again, this will give a slight recessed look. Group the four objects that make up the slider knob, then center everything to complete the slider.
Draw a tiny circle and fill it with blue. Double-click the Scale tool, enter 50%, and click copy. Drag the copy down about 2 inches. Hold down the Shift key while dragging to keep it aligned with the first circle.
Now select both circles and double-click the Blend tool. Choose Specified Steps as the spacing method, and enter 17 or 18. Click the Preview button and adjust to your liking. You should have an evenly-spaced series of dots, going from smallest at the bottom, to largest at the top.
Position the dots alongside the slider to complete the group.
Now for the knobs. Draw a circle about 40 points in diameter. Fill it with a radial gradient, and give it a 1-point stroke of 40% black, as in the image below. This will be the seat, or socket, for the knob.
Draw a second circle, slightly smaller than the first. Go to Object > Path > Add Anchor Points, which will add another anchor to each segment of the circle. Do this again, so you end up with 16 points on the circle.
Go to Effect > Distort & Transform > Pucker & Bloat. Enter 5%. Your object should look like the image below. Now expand the appearance under the Object menu.
Make a copy of the knob shape and enlarge it slightly. Send it behind the original and give it a lighter gray fill. Move it down and to the left a bit. We could use a 3D effect on the knobs, but to keep it simple, this lighter shape will serve as the side of the knob.
Using the Pen tool, draw a simple 3-point path. Click once to make a point at the center of the knob, then again at the edge of the knob, then again at the outer edge of the side shape. In the Stroke panel, make this path 2 points wide, with a round cap.
Go to Object > Path Outline Stroke. Now take the Direct Selection tool and drag out a point on either side of the outlined stroke shape to make it wider. Fill the shape with a gradient, to give the illusion of the line tapering down the side of the knob.
Draw a circle outside the knob, about 50 points in diameter. Make a copy of the blended dots from Step 20. Select it and the new circle and go to Object > Blend > Replace Spine. The dots will now follow the circle, but will not go all the way around. To remedy this, take the Scissors tool (C) and cut the path. You'll still be able to Double-click the Blend tool to add steps if you want more dots.
For a finishing touch on the knob, draw two circles and fill them with a radial gradient, going from black to transparent. Position one slightly to the left of the knob, and the other to the right and below a bit. Change the Blending Mode in the Transparency panel to Multiply, and take the Opacity down to about 30 per cent. Group All of the knob elements, and as you did with the pads, duplicate and arrange them in a set.
For the LED screen, draw a rectangle about 150pt wide and 100pt tall. As you did in Step 2, round the corners and expand the appearance. Fill it with a dark radial gradient. Make a copy behind (Edit > Copy, Edit > Paste in Back), fill it with a very light gray, and nudge it down a bit. This will give the look of a small lip around the screen.
Offset the original rounded rectangle by 3 points. Give this shape a blue stroke and a fill of none.
For the digits, use an LED style font, such as Digital-7 Italic. Type "888", make it a bright green, and set the Opacity at 50%. Then copy the type object and paste in front. Change the number and make the Opacity 100%. For a little extra somethin', you can apply an outer glow to the 888.
Now that you have the basic elements, it's just a matter of arranging them to make your MIDI controller. I did a quick trace of the outline and filled it with some subtle gradients to give it dimension and sheen, then I added text labels to the various knobs and pads. You could easily apply these techniques to interface design or technical illustration. Rock on!