Can you tell me please if you are starting and stopping the camera repeatedly, and the quality is getting worse and worse each time? I ask this question because the current version of the RealSense SDK 2.0 has a "memory leak" bug in it. It is referred to in the SDK's release notes as follows:
Memory leak when repeatedly closing and opening the device (DSO-8362)
Memory leaks cause performance to degrade over time, because the computer's memory is not being released correctly when a process is closed and so over time, more and more of the computer's memory gets used up, leaving less resources for programs to use.
This memory leak bug will likely be fixed soon, perhaps in the next release of the SDK. In the meantime, if you are experiencing a memory leak then the memory can be restored to normal by rebooting the computer.
May I ask please if the location where you are doing the scan has fluorescent lighting (like ceiling strip-lights)? This has been shown to have a negative effect on RealSense depth scans because fluorescent lights flicker at a rate that cannot be seen easily by the human eye and can create noise in the depth image.