Several ThingMarks and/or object tracking

[jbri]

Hello. 

I am trying to overlay a simplified (laser-cut acrylic sheets) real-world-mockup with CAD  data. 

With just one ThingMark, I experience problems with occlusion by my mockup.

Therefore 2 questions:

1. Can I somehow use several ThingMarks? For example, I can put 2 ThingMarks on my mockup and know the x, y, z positions of each one, so once one of the two is occluded, the other one will come into play
2. If I have a CAD model of my simplified mockup, can I somehow convince Vuforia to track this real-life-mockup and overlay it with my virtual CAD data?

Thanks for the support,

best wishes,

Jens

[ClayHelberg]

You can't add multiple thingmarks in an experience. You could try using a model target, which attempts to match up the camera shape of the object with the CAD geometry. Sometimes it works great, other times it can be a little fussy. It seems to work best if your object has lots of sharp edges and high contrast, and your CAD model has a very similar appearance to the real object (including color).

You could also try using an image target printed on the same scale as the equipment, and use it as a base for the equipment. In other words, print out a big mat of the image, put the equipment on top of it or in front of it, and scale the image in your experience to match the size and location in real life. We have had some luck with this approach where model targets are not appropriate and thingmarks are too small to provide reliable tracking for entire area of the equipment.

[jbri]

Hi Clay.

Thanks for your very fast reply. I had to check some details, before coming back to you. 

I gave the model target a try. It works quite well if I don't get too close to the mockup, then it obviously loses tracking and scaling. 

Two potential solutions come to mind:

• (simple/one button solution?!): I am still not sure if I use the full capabilities of the iPhone/Apple AR Kit. Sure, Vuforia needs to "see the overall mockup shape" to overlay the digital content. But after this initial stage, use of the interial sensors should take over control? Did I miss a tick-box where I can state: Fully rely on Apple AR Kit after model-target can't be "seen" anymore?
• Color, texture etc.: Maybe some background can help to gain a better understanding of what I am trying to achieve: 
  • this is the mockup I am talking about:
    
  • this is the CAD part to be overlaid:
    
  • will it help if I physically paint each of the "inverted-L-shapes" of the mockup in red-green-blue-black for example?
  • Are there smarter ways of texturing them? I was thinking of something similar to an erlking-car:
     
    So having a distinct structure that can be recognised. Physically printed to the mockup, and similar to a "stencil" in Autodesk Fusion on the CAD file. Do I run into limitations of such texture on fbx files etc.?

As this AR application is about showing details of the design, I need to get really close with the iPhone's camera and can't stop at "full visibility". Altering the scale of the mockup should have no influence in my understanding because the requirement of "full visibility" at 1:2/1:4 just implies get twice as close if scaled-down, and I still can't get inspect details?!

Thanks again for all your help.

Best wishes,

Jens

[ClayHelberg]

Hi Jens--

I'm not sure about the elaborate black and white skin you showed in one of your pictures--it might help or might not, you'd just have to experiement with it I guess. In that case, you would need to make sure that the markings match up between the CAD model and the actual physical framework, which might be hard to achieve.

Painting each of the four brackets a different color might help.

Regarding AR kit, did you make sure to activate "Extended Tracking" and "Persist Map" in your 3D Container properties? If not, switch those on and see if that helps maintain tracking when zooming in on the object.

--Clay