Thermia

Temperature in Thermia is calculated from a thermodynamic model: each enclosed volume holds an amount of energy that rises and falls over time, so a room warms or cools gradually rather than switching at once. Solar heating follows the time of day and peaks during the day, with raycast shadow occlusion deciding whether sunlight reaches a given position. Wind chill cools exposed positions, and the same raycast checks decide how much of an entity is sheltered.

Exposure is sampled from several angles with multiple rays, so a partly covered position receives partial heating or cooling instead of a full on or off value. A dynamic flood fill measures the enclosed space around a player, with a default limit of 13824 blocks. Block seals treat the edge blocks of an enclosure as walls, and a window or a partial block can let heat through or block it depending on its shape. Fire and other TerraFirmaCraft heat sources are supported, and heated items such as ingots and pots carry their own temperature.

Thermia requires Curios API and TerraFirmaCraft. Installation covers the server and each player's game. Files are published for NeoForge 1.21.1, with 0.2.1-beta as the latest build, released under the European Union Public License 1.2 and open source.