PopcornAssetBaker.exe

⚠️ This document is a work in progress. Information may be incomplete, inaccurate, or subject to change.

PopcornAssetBaker.exe is a command-line tool used internally by Blizzard to bake PopcornFX particle effects into binary .pkfx/.pkb files. It was accidentally leaked as part of Warcraft 3 development software in December 2024.

The tool is built on top of PK-AssetBakerLib — the baking library from the PopcornFX SDK that handles converting source effects and resources into runtime-ready binaries. In PopcornFX v2.x, the AssetBaker is part of the paid SDK and is no longer included with the free PK-Editor. Blizzard's version wraps this library with a simplified CLI that differs from the standard AssetBaker command-line interface — it exposes only five flags instead of the full set of SDK options.

The tool works and produces valid .pkb files in most cases. Note that using this utility is not required — the built-in "Quick Bake" function in the PopcornFX editor achieves the same result.

Basics

CLI Arguments

Flag	Type	Required	Description
-i <path>	string	yes	Input directory
-o <path>	string	yes	Output directory
-s	flag	no	Recurse through subdirectories
-q	flag	no	Quiet mode
-v	flag	no	Verbose mode

Config

The input directory must contain a config file at Popcorn/AssetBaker.pkcf.

Example contents:

Version = 2.5.1.63447;
CProjectSettingsBaking    $D857A09F
{
    PlatformSettingsList = {
        "x64:Builded",
    };
    BuildVersions = {
        "PC: desktop, windows",
    };
}

More settings may be needed depending on your project — custom configurations has not been tested deeply.

Unlike the standard PopcornFX AssetBaker, which exposes a rich set of CLI options, Blizzard's version only accepts the five flags listed above. All baking customization — such as resource oven settings, compiler switches, and platform targeting — is driven entirely through this config file. The config can contain additional objects that configure individual resource ovens (particles, textures, texture atlases, etc.).

For reference on what settings the underlying AssetBaker supports, see the PopcornFX baking documentation:

• Baking overview
• Particle oven
• Texture oven
• Base oven settings

How much of this is actually functional in the leaked build has not been fully explored.

How Baking Works

When you run the baker, it goes through the following steps:

1. Mount the input directory as a virtual file pack (the same file system PopcornFX uses internally).
2. Initialize the cookery — load Popcorn/AssetBaker.pkcf and set up the baking pipeline.
3. Register resource ovens — each asset type is handled by a dedicated "oven":

Oven	Handles	Input extensions
Texture	Images	.dds, .png, .jpg, .jpeg, .tga, .tif, .tiff, .pkm, .pvr
TextureAtlas	Atlases	.pkat
Font	Fonts	.ttf, .otf
VectorField	Vector fields	.fga
Particle	Effects	.pkfx
HBO	Serialized objects	.hbo, .pkma, .pkan, .pksa
Audio	Sounds	.mp3, .wav, .ogg
StraightCopy	Pass-through	.txt, .pkfm, .pkvf, .pksc

1. Scan the input directory for *.pkfx files (ignoring the Popcorn folder). Each file is routed to the matching oven based on its extension — the oven then processes it and any resources it depends on (textures, sounds, etc.).
2. Write output to the target directory. The target platform is hardcoded to x64. Particle effects (.pkfx) are converted to baked .pkb files; other resources are processed or copied depending on their oven.

In short: the baker recursively finds all .pkfx files, resolves their dependencies, runs each resource through the appropriate oven, and writes everything to the output folder in a runtime-ready format.

Note: The "StraightCopy" oven simply copies files as-is without any transformation. The "HBO" oven handles PopcornFX's internal serialization format.

Library

The baker expects to find the PopcornFXCore library at <inputdir>/Popcorn. Typically a Library directory is created automatically in the project folder, so the library needs to be copied to <inputdir>/Popcorn.

Boilerplate Project

Instead of setting up the config and library manually, you can use a ready-made boilerplate project: war3-pfx-boilerplate. It is a pre-configured PopcornFX 2.5 project for Warcraft III: Reforged that already includes the correct AssetBaker.pkcf and the relocated PopcornFXCore library.