Hardware Transformation and Lighting

Hardware Transformation and Lighting is a feature in FreeSpace Open that allows users to use high-polygon models in game. The engine also speeds up gameplay, thus the slowdown the higher-quality models would normally cause becomes inconspicuous.

Harware Transformation and Lighting, or HTL as it is commonly abbreviated, is a technique where certain calculations involved in the rendering (drawing) of the screen, such as lighting, are handled by your on-board video card (hardware) instead of being processed by your CPU (sometimes considered software rendering).