Methods, systems, and non-transitory computer readable storage media are disclosed for rendering portions of a three-dimensional environment at different sampling rates based on a focus frame within a graphical user interface. Specifically, the disclosed system provides a tool for marking a region of a graphical user interface displaying a three-dimensional environment. The disclosed system generates a focus frame based on the marked region of the graphical user interface and attaches the focus frame to a portion of the three-dimensional environment. The disclosed system assigns a first sampling rate to the portion of the three-dimensional environment displayed within the focus frame and a second sampling rate to portions of the three-dimensional environment outside the focus frame. The disclosed system renders the three-dimensional environment by sampling the portion within the focus frame at the first sampling rate and the portions outside the focus frame at the second sampling rate.