Most tutorials I see about Match Photo are sort of willy nilly, having you jump right in which most times creates a big mess that makes your eyes hurt. In this tutorial I’m going to share the method I use for Match Photo that produces reliable results every time, whether it’s for an interior, exterior, existing model, or new model.
What can you do with Match Photo?
Match Photo is a feature in SketchUp Pro and SketchUp Make that allows you to match your model’s camera perspective with a photo and overlay your model on top of it. This is useful for a number of scenarios:
- See what your model will look like in an existing space. Check out these awesome examples of Match Photo by @RTCool.
- Create a new model of objects in your photo by referencing the photo while you model.
- Measure objects in your photo by extrapolating from a single, known dimension.
- Apply textures from the photo to the faces in your model.
It all starts with a good photo
It’s important to have a “good photo” when using Match Photo. So what makes a good photo?
- The photo needs to have several reference lines in it that you know to be 90° from each other and parallel to an imaginary red and green axis. This is important because Match Photo works by manually aligning several “vanishing point bars” with these reference lines in order to orient the model axis to the photo. You only need two reference lines for each axis. The following images show several examples of reference lines you could use.
- Ideally, you want to have at least two intersecting vertical surfaces that you can use to align to the reference grid while configuring Match Photo. (An outside corner of a building, or an inside corner of a room, for example.) A third plane, like the ground, floor, or ceiling is also helpful to be able to identify in the photo.
- Make sure the photo was taken from a position where the reference lines are long, and the ends of each reference line are at different distances away from the camera. (Don’t take a picture of wall straight on, because the reference lines will be parallel and there will be no depth perception to infer the vanishing point from.)
- Don’t use a panorama, wide-angle, or fish-eye lens. The objective is to have a photo with as little distortion as possible. (Some cameras have built-in lens correction which counteracts the lens distortion, or you can use a program like Lightroom to apply a lens profile to the image.) Try to have your focal point towards the center of the photo, where there is the least amount of distortion.
- You should know the dimension of at least one distance in the photo. The last step to creating a Match Photo is to scale the model, so having some reference of the size of an object in your photo will make this task much more accurate compared to simply guessing.
TIP: You can create as many Match Photos as you want in your model. Each one will get saved in a scene, which can be recalled at any time.
Once you have a photo chosen for your Match Photo, identify a point in the photo that will represent the axes origin. This point should be where the 3 planes intersect, depending upon which perspective your photo was taken from. We do this because the reference grid projects away from the origin, so aligning the origin correctly will make the reference grid align with the three planes in the photo. So for this photo, my origin point would be this bottom outside corner of the building.
DOWNLOAD IMAGE & SKP
Click the button to download the file.
Setting up your model for Match Photo
This is the step that most people skip when using Match Photo, but it makes the process so much easier, and much more accurate. You should create some reference geometry in your model to help you align and scale the model while configuring match photo.
So if you are using Match Photo on a building, you should at least model a cube, and one of the sides of the cube should be dimensioned accurately to a known dimension on the building.
When creating this basic shape, the axes origin in the model and the origin point you chose in the photo should be in the same place. This not only makes initial alignment super straightforward, but it also makes it really easy to scale the model because everything scales away from the origin. If you’re not using a common reference point for the origin, scaling becomes more tedious because you have to go back and forth between scaling and moving the origin until you get the alignment right.
If you’re working with an existing model, you can always use the Axes tool to realign your axes if you need to.
Creating a Match Photo
Orbit your camera around to roughly the same perspective in the photo. Then, follow these steps:
- Go to Camera > Match New Photo > Select the photo you want to match.
- Drag the yellow origin point of the model (Where the Blue, Red, and Green axes intersect) onto the point in the photo that represents the origin. (If the actual point is obscured in the photo, that’s ok, just estimate where it should be.)
- If you find the interface too cluttered, it’s sometimes best to turn off the model visibility while you finish aligning the photo. Click on the Model checkbox to hide the model temporarily.
- Drag the red and green vanishing point bars over the reference lines in your photo, and adjust their end points to that the bar is parallel to the reference lines. The red bars should be aligned to lines that are along the red axis, and the green ones should be placed along lines that are on the green axis.
- Make the Model visible again by checking the Model Checkbox. The last step is to scale the model to match the scale of the photo. Click and drag the Blue axis to scale the model. Scale it until the part of your model that is dimensioned accurately aligns to the photo.
- Click Done in the Match Photo panel to finish editing your match photo.
You’ll now see your model overlaid on the photo. And since you took the time to create some reference geometry in the model, everything is scaled correctly to match the scale of the photo.
Match Photo Scene
Any time you create a Match Photo, a new scene will be added to the model. If you orbit away from a Match Photo, you can always get back to it by clicking on the scene.
If you ever need to edit a Match Photo, just activate the scene, then click the gear icon in the Match Photo panel.
Modeling while viewing a Matched Photo
Naturally, you can’t orbit while viewing a Match Photo scene, or else the photo will disappear. But there are some tips you can use to model while keeping the photo in view.
- Use the ScaleS tool while in X-Ray mode to scale parts of your model. To activate X-Ray mode, toggle its icon in your toolbar, or go to View > Face Style > X-Ray. (You could also activate a style that has X-Ray enabled already). X-Ray mode will enable you to see all of the scale handles, without having to orbit around to that face. Remember, you don’t have to use scale on the entire model. You could preselect faces outside of the Match Photo, then jump back to the Match Photo to perform the scale.
- Lock axis using the arrow keys to move entities along axis, when you’re not able to get a good perspective. Snap to other points in your model that you have a better perspective on. (In the video below, I used the MoveM tool to create a copy of the forward edge by tapping CTRL to switch to copy mode. I then tapped the left arrow key to lock the green axis, so I could snap to the center of the bottom edge. I then moved the line along the blue axis by tapping the up arrow.)
There is a lot you can do with Match Photo. Once you get past the initial confusion of the setup process, you’ll be using Match Photo more frequently. I hope this tutorial helped! To learn more about all of the features of Match Photo, check out :
https://help.sketchup.com/en/sketchup/matching-photo-model-or-model-photo
