Updated Dynamic Lighting (aka. UDL) is the new version of the Roll20 lightning system that is meant to replace Advanced Fog of War and Dynamic Lighting, combining them into a single, unified system. It features a stronger framework for future feature enhancements, is more performative, and has been updated for more current computing technologies. The old system is referred to as Legacy Dynamic Lighting (LDL).

In UDL, the old features of Advanced Fog of War have been renamed Explorer Mode to avoid confusion.

Updated Dynamic Lighting uses WebGL, which is available in most computer systems and is supported by all the web browsers that Roll20 supports (Chrome and Firefox). The Legacy Dynamic Lighting has always used WebGL, so the change here is that Explorer Mode (previously Advanced Fog of War) now runs on the same system.

Parallel Systems

Currently UDL exist in parallel with the Legacy Dynamic Lighting(LDL) until it reached feature parity and all bugs are fixed. It was released on April 8th, 2020 as opt-in feature for Pro/Plus users after having been available over a month on the Dev Server for Pro subs to try out.

While we continue development on Updated Dynamic Lighting and support for licensed products, both the Legacy system and the Updated will exist in parallel. However, when you switch from one to another, the revealed areas are not transferred over. So, for example, if you and your crew have been crawling through a dungeon with Advanced Fog of War on, and you decide to switch to the new Dynamic Lighting with Explorer Mode, your players won't see anything they had previously explored. Players can fix that by moving their tokens around to re-reveal the area.

Similarly, if you switch to Explorer Mode and then decide to hop back over to the Legacy system, anything you had revealed in the Updated system will be hidden. If you then switch back to the the new Dynamic Lighting, the revealed areas that you had revealed will still be there.

The Dynamic Lighting layer, where you can add barriers that block light and movement, continues to function for both systems, and you do not need to change anything on that layer.