Photo-Matching in SketchUp

By Aidan Chopra

SketchUp’s photo-matching feature is the kind of technology that’s so useful, so unexpectedly satisfying, that you just can’t keep yourself from clapping. So what does photo-matching do? You can use this feature to do a couple things:

  • Build a model based on a photograph: If you have a good photograph (or multiple photographs) of the thing you want to model, SketchUp’s photo-matching feature can help you set up things so that building your model is much easier.

  • Match your model view to a photograph: Perhaps you have a model of a building and a photograph of the spot where the building will be constructed. You can use photo-matching to position your “camera” in SketchUp to be exactly where the real-life camera was when the photograph was taken. Then, you can create a composite image that shows what your building will look like in context.

Photo-matching works only on photographs of objects with at least one pair of surfaces that are at right angles to each other. Luckily, this includes millions of things you may want to build, but still, if the thing you want to photo-match is entirely round, or wavy, or even triangular, this method won’t work.

Like some of SketchUp’s other features, photo-matching is more of a method than a tool: You use it to set up things, you model a bit, you use the Match Photo dialog box a bit, and so on. If you don’t know the basics of modeling in SketchUp yet, you won’t have any luck with photo-matching — it’s really more of an intermediate-level feature, if such a thing exists.

It’s daunting, but after you use it once or twice, it’s not so bad. SketchUp’s photo-matching method (at least at the beginning of the process) uses color as a critical part of its user interface.

The following elements of the photo-matching interface show up in your modeling window:

  • Photograph: Your photograph shows up as a kind of background in your modeling window; it stays there as long as you don’t use Orbit to change your view. To bring your photo back, click the Scene tab (at the top of your modeling window) labeled with the photograph’s name.

  • Perspective bars: These come in two pairs: one green and one red. Use them when you’re setting up a new matched photo by dragging their ends (grips) to line them up with perpendicular pairs of parallel edges in your photograph.

  • Horizon line: This is a yellow, horizontal bar that, in most cases, you won’t have to use. It represents the horizon line in your model view, and as long as you placed the perspective bars correctly, it takes care of itself.

  • Vanishing point grips: These live at both ends of the horizon line, and once again, as long as you did a good job of setting up the perspective bars, you shouldn’t have to touch them.

  • Axis origin: This is the spot where the red, green, and blue axes meet. You position it to tell SketchUp where the ground surface is.

  • Scale line/vertical axis: Clicking and dragging this blue line lets you roughly scale your photograph by using the colored photo-matching grid lines. After you’re done, you can always scale your model more accurately using the Tape Measure tool.

You also need to work with a few things that appear outside your modeling window:

  • Matched photo scene tab: When you create a new matched photo, you create a new scene, too. Clicking a matched photo scene tab returns your view to the one you set up when you created (or edited) that matched photo. It also makes the associated photograph reappear — handy if you’ve orbited into another view.

  • Match Photo dialog box: This is photo-matching Mission Control; it’s where you can find almost all the controls you need for creating, editing, and working with your matched photo.

  • Photo visibility settings in the Styles dialog box: Deep, deep down in the bowels of the Styles dialog box, in the Modeling Settings section of the Edit tab, you can control the visibility of your matched photo.