1. A system comprising: one or more processors; one or more cameras configured to produce images of an environment, wherein an individual image comprises pixel values corresponding respectively to surface points of the environment; the one or more cameras including a time-of-flight camera, wherein the images include depth images, and wherein a depth image is produced by the time-of-flight camera using a sensing duration within which a reflected light signal is sensed, an individual pixel value of the depth image indicating a distance of a corresponding surface point from the time-of-flight camera; one or more non-transitory computer-readable media storing computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to perform acts comprising: analyzing one or more of the images to detect an object within the environment; defining a region of the environment that contains the object; determining a distance of the object from the time-of-flight camera; selecting a new sensing duration of the time-of-flight camera based at least in part on the sensing duration and the distance of the object from the time-of-flight camera, wherein the selecting the new sensing duration comprises at least one of increasing the sensing duration to increase spatial depth accuracy or decreasing the sensing duration to reduce motion blur; obtaining a sequence of the depth images produced by the time-of-flight camera using the new sensing duration; and analyzing a portion of an individual depth image of the sequence that corresponds to the defined region of the environment to track the object over time.