How to use Photo Match in Google SketchUp 6

By Jessica Dolcourt (1/22/07)

Google's release of the newly improved and already insanely popular (and populous) Google Earth 4 boasts new capabilities for improved 3D images alongside more faithful renderings of terrain. 3D modelers are particularly enjoying themselves, thanks to the new "Photo Match" feature in Google SketchUp 6 that makes building 3D models and matching them to the terrain a significantly easier task.

Photo Match lets you build 3D designs from imported two-dimensional photos. Using the photo as a template, modelers get a leg up on scale and architectural structure, which fast-forwards the creation process. The models can then be integrated into GoogleEarth 4 for personal use--to visualize your remodeled abode planted on your block--or for permanent inclusion in the public landscape.

Though Photo Match makes the process of creating 3D models slightly simpler, there are still rules and concepts to keep in mind, especially if you're learning how to use Google SketchUp.

Step 1: Import the right image the right way

Photo Match only works as well as your understanding of spatial perspective. SketchUp helps you build a 3D object from a flat photo, but it's important that the photo you start with suggests its deeper dimensions. A flat photo taken facing square on won't offer enough visual clues to create a compelling 3D model, so choose a snapshot with angles, and avoid using cropped images.

Once you have your photo, choose "Import" from Google SketchUp's File menu, and open your image from the dialog box. It's important to select "Use for Photo Match" from the options on the right-side bar, and Google notes you should select "All image files" to make sure your image appears in the dialog.

Step 2: Mind your axes

Once your image appears in SketchUp, you'll notice a yellow horizon line and red, blue, and green axis lines that will help plot your photo's orientation. It's your job to match the axis lines to the parallels in your photo, since the program will only fill in geometry plotted along the axes.

Start by dragging the red and green axis segments over the most important parallels in your photo--the ones you'll be replicating with drawing tools. Click the tabs on either end of a segment to adjust its angle and length. Zoom in and out with your mouse scroll wheel to place segments accurately.

When you're finished with the major parallel lines, click and drag the yellow box to a "meaningful" place on your photo's geometry. With a photo of a building, this likely will be the bottom left corner of the foreground. This yellow box serves as your origin point, where all axes meet, and where you'll start building your model.

See how the corner you choose also moves the blue (vertical) axis line. Since this line affects the angle of all other vertical lines, you'll want to choose your origin point based on how closely the blue axis matches the slope of other vertical lines in your photo.

To start drawing, select "Done" from the Photo Match window. You can edit the axes at any point by right-clicking the mouse button and choosing "Edit Photo Match" or clicking the gear icon in the Photo Match window.

Step 3: Build your model (and heed these tips!)

Begin drawing (tracing) your first face at the point of origin, which is represented by a yellow dot. Once that first face is drawn, you'll be able to connect the geometry of adjacent portions of your structure.

It's important to pay attention to the dotted inference lines. They will appear colored if you're on an axis, or black if you're not. As always, you'll need to trust SketchUp's math over your eye; it's all too easy to create a structure that looks fine from one angle but is horribly out of whack when you rotate it. Holding down the Shift key while you draw keeps you locked onto an inference line.

Step 4: Visualize your model

While you can always use the paint tool to add color and texture, it will also write over your original image. There are two methods of adding details without obscuring the original lines. First, the X-ray feature will make your model transparent and allow you to see the outline and color of the photo beneath it. To turn it on, select "View," then "Face Style," and choose "X-ray."

Later in the modeling process, you can replace the model's appearance with the colors and textures from the photo underneath. When that option is ready, a "Project textures from photo" button will appear in the Photo Match window.

Step 5: Prepare to export

Your model looks good--you've got colors, textures, spatial accuracy, and maybe an extra component you've downloaded from the 3D Warehouse to give it personality. There's still one thing you need to do before you begin the process to export your model to Google Earth: group its components.

With the arrow tool selected, click and drag your cursor from one corner of your model to the opposite, diagonal corner, which will select all components. Then simply right-click and select "Make Group." To disaggregate the components, right click again and select "Explode."

And now, Google Earth is waiting for your creation. Be sure to also check out how to place your 3D models into Google Earth 4. For a preview of everything Google Earth 4 has to offer, tune in to Neha Tiwari's video.