3D Scanning Cars With Photogrammetry
 

Scanning cars with photogrammetry is perhaps one of the trickiest things we do here at Ten24, reflective surfaces, glass, etc can make for a very difficult subject, throw colour capture into the mix and things start to get complicated. We're not going to reveal any details about how we do it just yet but we are going to be working on a full tutorial in the new year that will cover everything that you will need to capture a car with a single DSLR in full colour to a level of detail that will exceed most laser / lidar systems costing hundreds of thousands of pounds. 

The example we're giving away on this page was actually our very first attempt at scanning a car around 2 years ago. We purposefully chose the hardest one we could i,e pure white with decals and coloured surfaces. The aim was to get close to laser scanner quality without destroying the car or without spraying the entire thing with expensive and hard to remove matting powder as used in our scanning reflective objects tutorial. 

Since this test our techniques have improved considerably and the were now able to scan with around 3 times to resolution of the free example. which we would now consider crude compared to what we have in store for the tutorial. 

Here are some more images of the scan loaded into Zbrush, As you can see from the renders below at the time there were some issues with scanning the highly reflective / refractive areas such as the headlights. Also, highly occluded areas under the wheels and around the exhaust suffered due to a number of factors including lack of image coverage and poor lighting on the day of the shoot. We now have full proof low-cost techniques to tackle these issues that will be explained in the tutorial. The textures on this model are also fairly low quality due again to the lack of proper coverage and changing lighting conditions. Due to the high reflectivity of the windscreen glass, the resulting glancing angle reflections have combined during processing to make for a pretty nasty white sheen. This effect may, unfortunately, be totally unavoidable however glass is transparent and as such has no colour so we see very little point in actually trying to solve this problem. Typically a model like this would be remodelled from scratch with shaders providing the glass surface rather than a captured texture. 

Technical Details 

  • Photographs used :: 482
  • Processing Software :: AGI Photoscan
  • Point Cloud :: 168,000,000 points
  • Capture Time :: 40 minutes
  • Processing time :: 9 hours in AGI
  • Camera :: Canon 100D 
     

We hope you can find some use for the scan, it's a perfect starting point for creating a 100% accurate model using just about the best reference you can possibly have. please be sure to read the legal information on the next page before downloading.
 

More images
 

   

   

AGI Photoscan scene

Further Experiments Using Reality Capture 
 

This is a second test we conducted using an improved scanning technique with better lighting and image shooting techniques, this car will most likely be the subject of the tutorial. This particular test still has its problems, as you can see from the images surface noise is an issue and whilst it's fairly minimal we think we can all but eliminate by shooting with a tripod rather than handheld. As you can see we have managed to do a much better job of the headlights and occluded areas under the wheel arches. This scan was processed using Reality Capture.

   

We would be very interested to hear from you regarding what software you would prefer us to use for the tutorial. AGI photo scan or Reality Capture, please let us know in the comments below.