Outside and dark environments, primarily. A stereo RGB camera approach isn't satisfactory when the conditions are less than ideal. I've also talked with people

Outside and dark environments, primarily. A stereo RGB camera approach isn't satisfactory when the conditions are less than ideal. I've also talked with people working in the space and they mentioned that a custom-integrated SLAM (i.e. not a prepackaged all-in-one module) is a big time-sink of corner cases if you want high-quality tracking, which is why "just use a module" is our fallback if we run into a complexity explosion. Front-facing cameras, hmm. I'm not sure I like it from a usability POV, but it's something to consider. I think going the extra mile and including internal cameras for a seamless UX is better, though.