Defocusing has been spoken of quite a bit, by Dan as well, so I’d imagine one would have the ability to focus as desired, if desired. Either way, focus should be close to a non-issue in most cases.
Digital cameras are performing autofocus based on either a contrast detection algorithm or phase detection. Given the fact GF is largely using smartphone technology, I’d imagine it’s contrast based autofocus, which is a bit slower but more accurate, and quite a bit cheaper to implement technology wise.
So, solid color I would say absolutely no problem. It’s going to detect a contrast difference between either the grate or bottom of the case - edge detection per se. A straight translucent material may pose a problem due to lack of contrast unless perhaps the lights in the housing provide an apparent difference in contrast.
I’d say general rule of thumb is if you could get your smartphone to focus, the GF will focus.
I’d imagine what you’re seeing through the preview screen before printing is provided by the cameras, so you should know pretty quickly whether the material image looks in-focus or out of focus and whether you need to manual focus. That’s assuming flat material.
I asked a question in another thread about laser focus. In the camera world we call it depth of field - which is basically the z-depth of what’s sharp enough to be considered in focus. I don’t know what it’s called in the laser world. Is the laser depth of field, so to speak, deep enough it could run over the slight curve of a MacBook without needing to change focus? I don’t know. Beta test me and I’ll throw my MacBook in