Baked physics

This article needs more links to other pages. You can help improve navigation by adding links to related documentation, such as entities or tools.

An example of cinematic physics from the beginning of  Half-Life 2: Episode Two.
(Click to view if GIF does not play automatically).

Baked physics, sometimes referred to as "cinematic physics", are baked animations created in an offline animation package that are not simulated in real-time, typically portraying large destruction events then played back in-game. Valve used Blast Code to create complex physics simulations in Source 1 games, most of which were done by Gray Horsfield. Blast Code is no longer available, however, there are alternatives.
In Condition Zero Deleted Scenes and Half-Life 2: Episode Two, baked physics are often played back in game at specific events, often for narrative purposes. In Source, baked physics animations typically get streamed in from ANI animation files, which fragment the animation data so it can get loaded on-demand in game.
When creating cinematic physics, it is important to keep the limitations of the target game engine in mind, such as limitation of object count per model, which may require using multiple models for a single effect. In Source, it is recommended to create the model in 3 states : pre-destruction, the actual destruction animation, and a post-destruction model that Source can show after the animation has finished.

This article or section needs to be cleaned up to conform to a higher standard of quality because:

Reason 

This concept is engine-agnostic and was not introduced with  Half-Life 2: Episode Two.
Baked physics are used in  GoldSrc as well, with extensive usage in  Condition Zero Deleted Scenes.

Confirm:In Left 4 Dead and Left 4 Dead 2, there is a folder named hybridphysx, inside models, contains baked physics (.ani) which are presumably seems to be generated using Nvidia PhysX then baked into the model. More info was later discovered as part of Aug 2026's Steam2 leak, as one of the pre-release build (Aug 6, 2009) of Left 4 Dead 2 required PhysX in order to play the game. Whether PhysX was originally planned to be added to L4D2 (before it was cut in final build) or it is intended for generating baked physics only on dev build of L4D2 remains unknown.

See also

• $animblocksize
• .ANI File Format
• Model Creation Overview

External links

• Cinematic Physics in 3DS Max - Legacy Interlopers.net Tutorial for 3DS Max
• RayFire Simulation System - Destruction system for 3DS Max
• SideFX Houdini - Procedural 3D Toolkit including simulation tools
• Blender - Includes primitive simulation tools
• Blender Fracture Modifier - Blender 2.7 build with destruction tools
• GoldSrc baked physics tutorial by The303 - Also applicable for Source