Real-time light-detection and ranging point decimation is provided. A system of a vehicle can allocate, based on a resolution for data points, a region in the memory for a tree data structure. The region can have a fixed-size for a duration of a flight performed by the vehicle. The system can receive, subsequent to allocating the region in the memory, first points captured by a sensor of the vehicle at a first resolution, and convert the points to second points having a second resolution that is less than the first resolution. The system can then provide, for storage in the region in the memory, the tree data structure that stores the second points. The tree data structure can be used in a terrain map generation function.