ARKit - basic 3D model

Question

I've been experimenting with ARKit hopping to create a demo in which the user inspects a house placed on a surface, or even inspects it from the inside if the model is expanded enough. So I've started with the Placing Objects demo and even with the basic project when you create a new AR app. But I come up to the same issue of the models not being placed correctly and the user not being able to move around the model.

I've taken a few .blend models which I converted to .dae and imported them inside the demo project. Some models (.dae) are so big that I can move inside them and smaller one instead of being placed on the surface I'm pointing at, are place above my head or far outside the screen.

Why is this happening, do I need to do something to the models to be placed as they .scn counterparts (standard models in the demo project)?

I tried to convert the .dae models to .scn with similar results.

Answer 1

First problem is connected to units you are using in blender, if you create a model using meters as measurement units everything is going to be fine. You can check units that your scene using following this tip. Please note that SceneKit is using meters.

I do believe that the second part of your problem (objects are placed far outside the screen) happens because object in .dae scene are not placed in (0;0;0) coordinate and have some other coordinate instead.