[In this tutorial, originally published in Game Developer magazine's 2012 Career Guide, developer and author Robin de Jongh explains how to create placeholder art for your next game prototype.]

So you've downloaded an amazing game-development SDK, or you've learned the basics of a scripting language, or you're already a coding genius. You're all ready to work, except for one problem: You have no art assets to work with.

When you're making a game intended to show off your talent, it's important that you don't draw attention to your weak points. If you are pitching yourself as a coder, your game shouldn't look like it came from a four-year-old's sketchbook (unless it's supposed to). Your code might be immaculate, but your audience will be too distracted by the hideous visual style to care. You can get around this by making art that looks visually appealing, clean, and finished- but still temporary. Stylization is your friend!

Let's say you have an idea for a great game and a clear idea of how it should look in your mind's eye. Now, take one item at a time from that imaginary ensemble and strip it of color, shading, and fine details until you're left with a form that represents your object. It is not your object-your object will be far more detailed, colorful, and alive than this. Take this stripped-down object and quickly draw it with a pencil. What you have now is a concept asset, and if you keep all of your game art in this style, anyone playing your game will see that all it needs is a hotshot artist.

Of course, you can't use a pencil-and-paper sketch for your prototype's art, because you'll need the geometry and size to be consistent in order for you to handle collision detection, physics, and so on. So we're going to use SketchUp to build our assets instead.

Starting With A Sketch

SketchUp is a free, easy-to-use tool that's well suited to making 3D models and 2D art. We're using SketchUp for this article because it has display features that make it easy to make your art look like a preliminary sketch, which is important for reminding your audience that the game is still a work in progress. Yet the assets you create will be geometrically identical to the finished asset you might commission in the future, so you can develop and test your game code as you would the finished article.

(Note: At the time of this writing, SketchUp is in the process of being acquired by Trimble. Trimble plans to keep the free version of SketchUp, so the contents of this tutorial shouldn't change, but the download URL might.)

Sprite Sheet In 20 Minutes

Every game developer should know how to create her own sprites. Downloading someone else's stuff from the Internet is just going to limit what you can do with your prototype's visual style and how you can move a sprite, and you don't want anything to impede your creativity.

Download SketchUp (the free version), install it, and fire it up. In the first window, click Choose Template and select a template that suits you (Millimeters, Meters, or Feet and Inches), then click Start Using SketchUp. Once the main SketchUp window opens, select the Rectangle Tool on the left-hand side of the toolbar, and draw a rectangle that you're going to use as a box that borders your new sprite. Note that depending on which template you select, you will either start with a top-down or isometric view. Click the top view icon or use the middle mouse button to rotate the view so that you easily see the red and green axes. We're going to draw a spaceship next.

Draw an outline of a spaceship in SketchUp.

Select the Pencil tool, and start drawing a rough outline of half your spaceship at the middle of the top edge of the rectangle. Erase the rest of the rectangle, and then use the PushPull tool (a cube with a red arrow pointing upward) to give the shape some thickness. You can continue to use the pencil tool to draw in a little more detail here and there, and whenever you draw a closed shape, just use the PushPull tool to add depth.

Use the Pencil and PushPull tool to draw shapes and give them depth.

Now triple-click on your half spaceship to select the entire thing, and then right-click and choose Make Component. Use the Move tool and hold Control to drag a copy of your half-ship to the side (Option-click if you're on a Mac), and then right-click and select Flip Along, Red Direction. Move this half to join it with the original half. You now have a finished ship shape! Select both of these halves, right-click again, and choose Make Component again, and then select Set Component Axes and move the axis to the middle rear of the ship. This allows you to rotate it more easily, which will come in handy later.