I've been thinking about building a small UAV with an onboard LIDAR, just for fun. I'm interested in SLAM and autonomous flight indoors and thought that I would need a lidar to get a 3D map of the environment. Now, I've spent some more time looking into SLAM techniques and have seen very impressive results with simple RGB cameras, not even necessarily stereo setups. For instance, these results of the CV group of TU Muenchen. They are capable of constructing 3D pointclouds from simple webcams, in real-time on a standard CPU.
My question: are there cases where you'd still need a LIDAR or can this expensive sensor be replaced with a standard camera? Any pros/cons for either sensors?
I'm going to list some pros/cons that I know/can think of:
LIDARs are better at detecting featureless objects (blank walls) whereas a vision-based SLAM would need some features.
Using LIDARs would be computationally less intensive than reconstructing from video
The single RGB camera 3D reconstruction algorithms I found need some movement of the camera to estimate depth whereas a LIDAR does not need any movement.
Using a single camera for SLAM would be cheaper, lighter and possibly have a better resolution than a LIDAR.