On forum: 05/03/2005
If its not in the game is it something that modders could put in pretty easily?
Most of the time in games there's a specific entity or invisible texture which allows the player to "climb" a surface. For HalfLife, it was called a func_ladder, which was made from a rectangle smeared with a invisible texture. This rectangle basically told the game that when the player reached these coordinates (x,y,z) that the player was to be put into a "ladder-climbing" mode, where forward/backward would be turned into a up/down motion. Same thing with HL2 and Doom 3...
Probably the same with Stalker.
Unless, of course, Stalker's "ladders" are actual math equations to see it climbing a surface is possible (IE: detecting distances between like-angled surfaces; math calculations for the distance between rungs in a ladder) ... But i doubt that. So, unless Stalkers' map-makers are insanely extensive, and func_ladder every conceivably "climbable" surface, you'll be able to climb your trees. So, for climbing every and any tree in the zone...
... Then a Controller comes by and *POP*, s'plodes your brain inwards!