Thermal Erosion is a type of geomorphology that occurs with temperature changes over time for which the repeated heating and cooling of rock causes pieces to break and flake off and fall to lower altitudes.
With cliff type geology the flaking off of the rock can change the shape of the cliff face, with an accumulation of rock pieces called talus and scree at the base of the cliff face.
The thermal erosion function in TerreSculptor is based on the research of Musgrave, Kolb and Mace. It extends their research to include additional functionality. It also uses the full Moore cell neighbor technique to provide a more accurate simulation, but at the cost of longer computational time.
The erosion dialog provides full access to all erosive properties, such as the minimum and maximum altitude difference for talus slopes, erosion strength and time, and includes the option of saving any auto-generated masks for use as weightmaps on the terrain within the video game engine. These weightmaps are typically used to provide accurate and natural-looking terrain texture mapping along areas where thermal erosion deposits have accumulated.
Visually, the results of thermal erosion are increased cliff faces, accumulated piles of talus and scree at the base of cliffs, and the smoothing of other areas where scree has filled in depressions.
The erosion dialog:
The 3601x3601 DEM file we are going to erode:
The DEM file after thermal erosion:
Note that the amount of erosion was increased to show the effect and will typically not be used at this strength.
Also note the sharp cliff faces and accumulation of talus below the faces.
The auto-generated deposit mask that can be used as a terrain weightmap, resampled from its original 3601x3601 size:
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