Find and deduct measurements from a picture in Sketchup | Match Photo Tutorial

If you are an architect, interior designer engineer or surveyor, there are situations were you don't have time to visit a site or travel to do a survey and take measurements esp for interior spaces, sometimes you are onsite and have no tape or tools to do your work and even worse, you want to measure inaccessible areas you can't reach without laser meter like roof elements, would you wait or give up ?

In similar cases Sketchup Match Photo is a life saver, you can either take or ask clients and owners to take pictures from all possible corners/angles to find measurements, no need for any online tool or mobile app or invention to solve this problem.

The pictures will be retraced in 3D by creating one or multiple Match Photo scenes to be used like a manual photogrammetry, then once you finish tracing you can scale the entire model using the Tape tool (T shortcut) and extract the desired measurement.

How to Extract Accurate Dimensions from a Single Photo in SketchUp :

1.  Set your Match Photo Scene

   Open Sketchup, from the Camera Menu  > Match new photo and select the picture you want to use as reference.
   
   



Sketchup Camera Menu Match New Photo

2. Place your origin point, axis and vanishings points bars

   Move the yellow square (origin point) to the bottom corner point where your camera lens is pointing to, then move the green and red (XY axis) vanishing point bars to align them with the receding horizontal lines of your photo perspective in both directions, hit Done when you finish, -refer to the image and video below for this step-
   
   

   

   Sketchup Match Photo Setup

    
    

3. Retrace over your Match photo in 3D
   

   Start tracing in 3D over your Match Photo scene using the line tool (L) and Push/Pull tool (P), start drawing from the origin point and make sure you are going in the right directions (Green or Red or Blue axis), draw faces and match your interior scene space (walls, ceiling, openings, etc...) you can orbit to verify you are doing well and go back to your Match Photo scene at any time.

   If you find that the line tool increments are not working as expected try to change the units, increase the precision and disable snapping (from the model info window > Units).

4. Scale your Match Photo 3D scene :

   Once you finish 3D tracing your scene, the final step is to scale it, select the tape Tool (T shortcut), hit the Alt/Ctrl (Mac-win) to turn off the (+) toggle, click once to define the first point, then click a second time to define the second point then type the corresponding length (matching your model units mm, inches, meters) between these two points and hit enter. (Select yes for the prompt asking : do you want to resize the model)
   
   

   

   Sketchup Match Photo model resize prompt
   
   

• Having a single dimension: in this case, you can scale your model directly using the T shortcut, select the two points of this known length, enter the value hit enter (as in the example above, I used the window sill height which is 90 cm), the entire model will be scaled proportionally and the accuracy is +/- few millimeters (as a verification step: the tile measurement readings are correct in our case 60 x 60 cm)
  
  
• Having no dimensions at all: the worst scenario, you will need to "guess & verify", or use as reference a standard common/known length like door width, tile measurements, ceiling height or stair raiser, since the model will be scaled proportionally, dimensions in all axis will follow and should read correctly. To verify, check and compare against 2 or 3 other known objects, you can re-scale if necessary. (scale using the largest length possible for better accuracy and tolerance -/+).
  
  

Sketchup Match Photo model scaled accurately

And Voila ! your Sketchup Scene is now scaled, you can extract measurements, angles, areas, perimeters, distance between any points, in case you have other sections to retrace in 3D, you can either work on the same Sketchup model and add a new Match Photo scene or create a new file from scratch.

Benefits of using Sketchup Match Photo as a survey tool:

I know this trick sounds smart and weird at the same time, but in the AEC (Architecture, Engineering, and Construction) world, "Site Surveying" is a massive pain point, sometime you easily find yourself working form multiple references that don't match, measurements taken by someone else (unreadable handwriting), you forgot to measure certain areas or made mistakes, situations where you want to quickly check an area to confirm whether something fits, renovation projects where the existing dimensions are a critical point, endless stories...   

- See the accuracy comparaison below (measurements taken manually vs work straight  from Sketchup Match Photo)-

 Measurements  I took onsite (took me an hour)

The same space modeled accurately in 2 minutes (scaled from tiles reference)

• You can start work without a survey/measurements, just a picture.
  
• Suitable for remote work, no need to be onsite, just pictures from corners.
• No measurements tools onsite, no tape, no laser meter, no pen no paper?
• Save time to do quick drafts while remaining accurate.
• A mistake or unknown or missing measurement? confirm using a picture.
• Unreachable inaccessible areas like high roof elements, ceiling height?
  
• You want to do interior wall elevation drawings?
• Your client can't take a survey or unable communicate measurements? ask for a picture.
• Need manual Photogrammetry for interior spaces > Match Photo is your ultimate solution.
• Struggling with expensive 3D scanners or inaccurate phone apps to scan a simple 4 walls + ceiling interior space that ends up with a 1 millions vertices mesh and requires cleaning? the answer is Sketchup Match Photo !
  
  

Conclusion :

As demonstrated above, with single a dimension or without dimensions at all, you are now able to proportionally deduct dimensions from pictures, save the survey time and efforts to do drafts, quickly draw floor-plans and interior wall elevations, then confirm later on site when you have time or access, and in all situations you will be able to start working with a minimum input and without giving up or waiting for measurements to come.

If you are new to Sketchup and never used Match photo before, you can download a free Sketchup Make copy and give it a try (Match Photo feature is not available in  the free Sketchup Web version). This trick is not limited only to the architecture, interior design or construction fields, but can be used to find dimensions of any geometric shape depending on the context of the picture and the reference dimension you know.