I am working on a POC using the sample provided by apple https://developer.apple.com/sample-code/wwdc/2017/PlacingObjects.zip.
Right now placing object works fine after detecting the surface. But when i move the object from the detected surface to some other space like walls or some obstacle, it is overlapping with the 3D object.
Is it possible to detect the obstacles while placing/moving the 3D object through camera? Is there any sort of API available in ARKit to find the obstacle in the surface?
If not is there any workaround or calculation that we can do to find the obstacle/wall and let user not place/move the object above/beyond the obstacle/wall?
The short answer at this stage is no, unfortunately.
Detecting vertical planes, or objects in a scene, is quite difficult. My understanding is that Apple is working on vertical plane detection, and that there are a couple of startups doing the object detection stuff.
The best option will be to wait for 6d.ai, as this is what they are working on (although they are in stealth so hard to tell exactly).
If you have any Core ML experience then you could use an object detection model (find a third party one) to recognise objects in a scene and use that as a proxy for geometry that is off limits. There's also Matroid which provide object detection / tracking capabilities.
The following are not specific ARKit / iOS examples, but might help you later on.
Vuforia has support for scene understanding: https://library.vuforia.com/articles/Training/Getting-Started-with-Smart-Terrain
Hololens sort of has support for it as well: https://elbruno.com/2017/04/21/hololens-spatial-understanding-vs-spatial-mapping-and-a-step-by-step-on-how-to-use-it/