Visualization techniques for data labeling

One embodiment provides a user interface (UI) that permits users to select how point cloud colorings determined from multiple data sources are blended together in a rendering of a point cloud. The data sources may include photographic, label, and/or LIDAR intensity data. To improve frame rates, an aggregated point cloud may be generated using a spatial hash of a large set of points and sampling of each hash bucket based on the number of points therein and a user-configurable density. Sizes of points in the point cloud may decrease proportionally to distance from a viewer, but increase based on an activation function that enlarges points greater than a threshold distance from the viewer. In addition, luminance statistics for sub-regions of photographic data and dominant colors determined from photographic data may be used to automatically determine color properties to apply to a point cloud coloring.