The Super Quick, Useful, and Dirty (SQUAD) Tabletop Tool came out of the need to describe spatial relationships with a group of pen-and-paper RPG players, especially in situations where a traditional grid and physical miniatures were not convenient. It’s a lightweight, kind of ugly, performant, free, 3D, browser-based tool to help DMs, GMs, and Keepers of all sorts quickly whip up a combat encounter, dungeon, et al. Using an automated, resizable grid system, it visualizes distances, obstacles, players, enemies, AOE actions, and physical locations. It’s released for free under the Creative Commons BY-NC-SA 4.0 license and is considered “as is,” with no support agreement whatsoever. Basically, it helped my game group out a bunch, and if it can help you too as it is—all the better.