Valve reportedly in the optimization phase of Half-Life 3: new NPC AI behavior sounds next-gen

Valve is reportedly in the optimization phase of development for Half-Life 3, which I'm really hoping gets announced officially on April 1, just for the developer to troll the entire world.

Half-Life 3 is reportedly codenamed "HLX" and was discovered during recent updates to Valve's other games including Dota 2 and Counter-Strike 2, with a new video posted by Gabe Follower, who details a bunch of new discoveries, and some of them sound really, really exciting.

Valve is reportedly working on a new artificial intelligence (AI) system for its NPCs in Half-Life 3, that acts like LOD (level of detail) with the graphics side of the game. The way this works is how LOD will use higher-quality textures on the environment, characters, items, and more in close proximity to you, reducing the detail past a certain point so that your GPU isn't just loading textures unnecessarily at large distances away from you.

Half-Life 3 with a LOD-style system for its AI behaviour for NPCs and enemies in the game sounds like a great idea to save on resources, as well as improve the intelligence of the enemies you're fighting, without putting unnecessary budens on your hardware to run ALL of those advanced AI-powered NPCs at once.

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NPC AI behavior: setting time intervals, medium level 4x per second only 1 at lowest level. Different settings on different levels. Turning on and off behaviour elements, automatic, or high for best results, medium, and very loiw -- NPC stops making decisions, update frequency to thinking is minimal.

More features include the maximum number of NPCs that can be controlled simultaneously, with the feeling and sensation of being in space based on some general factors and based on what the character sees with their eyes. Another very interesting note is that Valve is allowing NPC behavior to feel the threat of rising temperatures and burning surfaces in Half-Life 3, which would see NPCs behaving differently based on environmental factors like a flames from a fire next to them, or an electrical or water-based threat.

More tweaks include decision-making, navigation, turning on and off more complex motion animations, following objects with their eyes or turning their head. The fear of flinching due to damage event happening in front of them is on the cards for the AI NPC behavior in Half-Life 3, where if an NPC is shot, they can warn others.

• Read more: Half-Life 3 to push boundaries of game physics, destruction, NPC AI behavior in fresh leaks

Fire in the game will be next-gen, where flames will spread and burn differently depending on the surface: plastic and wood burn differently in the game, making for some next-level firefights. Valve is tweaking how the surface transmits or absorbs sound, and how much sound resonates with the room, causing objects to vibrate or reflect sound waves, creating echoes.

Valve is also cooking up movable navigation mesh, including altered gravity. Currently, in most Valve games, the navigation mesh for NPCs is generated at the map compilation and can slightly change in-game when physical objects get in the way or when a door closes. This means that NPC AI behavior will adapt to changes in location or gravity, so if there was a moving platform, NPCs can suddenly adapt their behavior to handle the changed environment around them.

Deformable props and destructible environments are coming to Half-Life 3 according to rumors, where metal can be dented, rubber bounces, and objects are left visibly dented and damaged. Valve has also reportedly made improvements to the dynamic hair system, with improved shading and interaction with the wind.

Wind is a big thing in Half-Life 3 it seems, where wind strength, direction, and even noise are being worked on... all changing dynamically. There are strands of code that tease artificial air streams that can flow around objects and NPCs or the player. Could we have wind-related weapons in Half-Life 3?

A lot of these new NPC AI technologies and behaviors sound perfect for Left 4 Dead 3...