Leaf Last edited 10 months ago2023-12-18 10:03:53 UTC

A leaf is the end node of any hierarchical tree data structure*. In the context of BSP trees, it's the end node that describes a portion of the level geometry after the BSP partitioning stage is done.

Properties associated with each BSP leaf include:

• Contents - whether this leaf is solid, empty, water, ladder, etc.
• Faces
• Potentially Visible Set (PVS) - a yes/no list that indicates whether every other BSP leaf is visible from this leaf. This is what VIS generates. If VIS is not run the PVS list is empty, telling the game that every other leaf (essentially the whole map) is visible in every leaf.

When two leafs connect there is a portal, and VIS does calculations for the PVS by doing algorithms against the area of the portal. The portal file is generated separately by the BSP compiler and not included in the final BSP file.

Associated Goldsource Error: leaf portals saw into leaf

* It follows the analogy of real life trees, which has a root, branches, and leaves at the end.