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Large 3D Object Target

March 22, 2019 - 6:50am #1

Hello,

I was planning on following the steps in the Vuforia Object Scanner User's Guide in order to import a 3D Object Target into a database in Vuforia. These are the links to the guides I used: 

https://library.vuforia.com/articles/Training/Vuforia-Object-Scanner-Users-Guide

https://library.vuforia.com/articles/Training/Object-Recognition

However, the object I am scanning is larger than the objects scanned in the guides, and would not fit on the object scanning target. Would it work if I printed a larger version of the object scanning target, or is there another way to go about scanning this object? Attached is an image of the object.

AttachmentSize
Image icon IMG_20190321_105610.jpg2.23 MB

Large 3D Object Target

March 26, 2019 - 9:00am #2

Hello,

Attached is an updated version of the Object Scanner target. These PDFs are scalable as they contain a vectorized image, instead of a bitmap. This means you can now print it to any scale without degradation.

Note: This has also been made available as a forum sticky post: https://developer.vuforia.com/forum/object-recognition/printing-large-format-version-vuforia-object-scanner-target

Reviewing your target, I'm concerned that it is missing a key property to perform as an Object Target: "The surface of the object should have contrast-based features." Your object's features look to be driven by the 3D textures, which are lighting dependent. This means that environmental lighting differences between the scanning phase and the detection phase could make the object undetectable.

There are many factors that can affect the tracking performance of a Object Target, both during the scanning process and when running an app. Most issues with Object Targets can be traced to the creation of the .od file using the Vuforia Object Scanner. Be sure to follow the scanner app instructions: https://library.vuforia.com/articles/Training/Vuforia-Object-Scanner-Users-Guide, paying close attention to step #8 in the article.

  • When creating the .od file, was the model scanned in an environment that was free of background details which may have introduced features that were not part of the model? Scanning in 'cluttered' environments can introduce false detection/tracking points.
  • When creating the .od file, were there any specular reflections on the model introduced by environmental lighting? Scanning objects that have reflective surfaces under direct lighting can introduce areas with no detection/tracking points.
  • Are you using the recommended devices referenced on the tool download page?: https://developer.vuforia.com/downloads/tool

In our labs, we utilize four primary strategies for creating an optimal Object Target scanning environment:

  1. All background surfaces are colored at 18% gray. An easy, off-the-shelf solution is to buy bed sheets near this color and drape everything in the environment that could be seen by the scanning device's camera.
  2. No direct lighting. We use light boxes and/or diffusers to eliminate direct lighting upon the object and minimize any spectral reflections.
  3. Utilize a 360 turntable to re-orient the device. This is especially helpful when you've set your environment to near ideal conditions within a limited area. You can spin the model and scan in 360 degrees without having to move around it.
  4. Be sure that the environment in which you’re testing (via the Object Scanner app ‘test mode’) is the same in which you’re verifying tracking (via the sample code). Environmental factors such as lighting, shadows, spectral reflections, etc. can negatively affect tracking performance, so awareness of how the environment is interacting with your model is important for qualifying performance.

Lastly, be sure to use meters and the default scale as this can also impact the feature's accuracy and performance.

Thanks,

Vuforia Engine Support

 

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