©2019 by fieldWorks

  • sf-logo-black
  • Vimeo - Grey Circle
  • Instagram - Grey Circle
  • Twitter - Grey Circle

Super fast photogrammetry

For those who don't have time to take 150 photos, looking vaguely deranged and obsessive to passers-by who might be tempted to call the police...

I'm calling it SNAP, CHOP, GO

I've been playing with ways of creating content as almost the digital exhaust of simply going about by normal day. I often pass things that I realise would make great candidates for photogrammetry and, more usefully, could be used to populate the the texture library that I plan in my head. I've never been entirely satisfied with the surface textures I find online; they are usually a compromise on my original vision, and as soon as one starts compromising it's a slippery slope! So here, in a few simple steps, is a workflow for texture collection that doesn't require a huge time investment.

  1. On your camera, be it a phone, high-end mirrorless or DSLR, get it ready to record in video mode - if you can record in slow-mo, more the better!
     

  2. Approach your subject, phone (or camera) in hand.
     

  3. Hit the record button and make several, slow, steady, traverses around the subject. If your subject is a object you have access to all sides of, then make a full orbit of it, with the camera at different angles. (This is the SNAP stage)
     

  4. If you have such a thing as a selfie-stick, perhaps repeat step 3 to get those hard to reach angles!
     

  5. You now have 1...n videos on your device. Move them onto your computer. You know how to do that...
     

  6. Install ffmpeg from here , but bear in mind that it's 3rd party software and I take no responsibility for whether it works or not and for any ill-effects on you, your computer or your offspring.
     

  7. Run this code snippet in console (This is the CHOP stage):


     

  8. You should then have 1 jpeg for every second of footage you capture in stage 2. You see where this is going right?
     

  9. Using your photogrammetry software of choice, import said photos into new project and start processing! (This is the GO stage!)
     

  10. (optional) If you are using Agisoft Metashape you can cut your processing time down by missing out the Dense Cloud stage, and build your mesh using Depth Maps instead

‚Äč

Caveats? Well this is a quick-fire workflow, best suited to grabbing textures for reuse on other models that you've created from 3D packages. Also, the lower density point clouds have a nice aesthetic all of their own. However, if you need high quality outputs, you'll still have to put in the time; think about your capture, your angles, the details, your strategy, your overlap, blah blah blah.

ffmpeg -i [the name of your video file here] -r 1/1 $filename%03d.jpg