I build a level in WED and use ent_type(NULL) to check what kind of map it's build ... ent_type always returns 3 (Mesh based BSP map). I am at a loss to understand how the engine builds a ABT map.

The manual states "The A7 engine automatically uses an ABT for levels that don't contain a precalculated BSP tree" ... I assume this means that we don't need to build a map in WED and rather create it on the fly just like in earthball.c example??

Incidentally earthball.c also returns 3 as ent_type. Can someone shed some light on this?

A7 behaves a bit different in this.
If you build a level youre able to choose between Simple Map(ABT) and BSP Map - If you open the wmb file the level-geometry is rendered in the selected mode.
Entities dont use these render trees at all(at least i unterstood so) - so if you open an empty level with level_load(NULL) none of them are used because there is no level-geometry.
But i dont know the ent_type command at all and i cant find it in the manual.

Hello, I think I understand what you mean, selecting "Simple Map" should build a ABT level ... I need to do more tests on this. the "ent_type" command can only be found using the search options in the CHM file ... just click on search and type in "ent_type". For some reason, the command has not been added to the index section of the help file ... if you pass a NULL as parameter to ent_type command it should tell you wheather your map is old stype BSP or new A7 BSP/ABT tree.