Enhanced Terrain Layer
Adds a Terrain Layer to Foundry that can be used by other modules to calculate difficult terrain.
Draw a polygon onto the map to represent the terrain at that location. This tool functions the same way you would use the polygon tool to draw polygons shapes to the scene. Left drag to start the shape, left click to add a point, right click to remove a point, and double-click to close the shape when you're done. You can then set how difficult that terrain is to move through, and what type of terrain it is, and what height the terrain affects tokens.
Switching to the select tool you can resize an area or reposition the area as you would with most object in Foundry. You can also delete an area by pressing the delete key while the the area is selected.
The Terrain Layer will also let you assign difficulty to a Measured Templates. You can use this for spells that set difficult terrain.
And it will also calculate other tokens so that when you're moving through another creatures square it will count as difficult terrain.
Calculating measurements does require a ruler that interfaces with the Terrain Layer. I'd recommend Drag Ruler and Terrain Ruler as they've been developed to work with Enhanced Terrain layer.
Terrain Layer can either be shown all the time, or hidden until a token is selected and dragged across the screen. This can be changed using the toggle button with the other terrain controls.
You can also set blocks of Terrain to be active or not active, so if the difficult terrain is only temporary or conditional you can control it.
You can also set the environment that the difficult terrain represents. So if you have water, or rocks, or arctic tundra you can record this information. If you have a system that allows characters to ignore difficult terrain of a certain type, and a ruler that supports checking on this, then it can be added to the calculations.
As of version 1.0.21 you can set the colour of each environmental terrain as well as setting the default colour of terrain for a scene, and the overall default colour.
Please see the project site for help developing code that uses this Terrain Layer.