Hi everyone! v4.5 was a pretty good release; we got a lot of things accomplished. More things are on the way, however...

Progress is continuing on an upcoming patch. We're working on a series of improvements and new features, as well as many bug fixes / tweaks.

One item I'd like to talk about today is that we've been working on a new navigation system for NPCs. We're replacing Half-Life 1's old path finding system with our own. The feature set of the path finder will be similar to what you might find in a more up-to-date game engine like Unreal Engine 3 or Source.

The following screenshot shows an outdated development version of the system. It illustrates roughly how the waypoints for NPCs are calculated:

The new path finding system starts from designated positions on a level, and flood fills the entire map to find walkable space. These points are mapped onto a waypoint grid and all walkable connections are computed. From there, the locations are grouped for fast look-up.

What does this mean? Well, it means the path finding will be pretty damn fast - servers will see reduced CPU usage. The initial version to be released will be a bare-bones replacement with more focus put towards getting the basic necessities to work flawlessly.

Though we wont initially be focusing on fancy path finding yet, a small handful of AI enhancements will be included. For example, soldiers will be able to calculate better cover positions and routes, based on the location of nearby enemies. No longer should you see a soldier run towards the enemy when it really wants to run to cover. NPCs will also be able to account for dynamic obstacles, like other NPCs blocking their path.

After the initial version of our path finder (to be included in an upcoming patch), we will then start formulating plans to incorporate ladders, elevators, jump locations (e.g. Headcrabs jumping into and out of vents), and other suitable enhancements.