Disable Zoom Feature While Using Lens

Hi CyreneQ, sorry for the delayed response. Took a second to figure out what was going on. So, global.touchSystem.touchBlocking = true does in fact disable the two finger pinch zoom / zoom out. However, what isn't supported is disabling the zoom while recording where you swipe your finger up from the record button. I've created a ticket for our team to investigate adding this to the touchBlocking system. At this time, you can disable the two finger pinch with touchBlocking but unfortunately will not be able to disable the record swipe up. 

One additional question, can you elaborate on why you want to disable zooming? Would be helpful to better understand the user experiance you're shooting for. 

Also, to answer your other questions, there is also currently no way to make static meshes not scale when the user zooms in and out.

Unfortunately, you won't be able to fix the case where the camera zooms in in the little camera preview.

That said, it is possible to fix the ball by using an Orthographic camera (which doesn't account for FOV / perspective and hence doesn't zoom):

• Create an Orthographic camera. The easiest way to do this is to create a new billboard (Add New -> Billboard) and then delete the billboard sprite that's created underneath the billboard. You actually already have this camera in your scene because you are using billboards. 
• Assign the 3D model to the orthographic layer. In the inspector panel, select the "Orthographic Layer" in the layer setting (top right corner of the Inspector)
• Parent the 3D model to the orthographic camera by dragging it onto the camera in the objects window
• Now, position your model so it renders in the right space. Note, perspective is not accounting for perspective (which is why the object won't zoom), so if you want it smaller or larger, you want to scale it rather than move it closer or farther away from the camera

Hope that helps!