People familiar with the original Halo Editing Kit (HEK) will feel very much at home and will enjoy the expanded features of the Halo 2 Map Editor tools.
The biggest difference users familiar with the HEK will notice is that getting a level into the game is easier. Construction of the level and its subsequent compilation of the exported geometry are more user-friendly.
Halo 2 Map Editor Launcher: Map Editor Launcher gives quick access to common editing functions such as compiling and lighting the level, creating a .map cache file, and compiling .bitmap files with a graphical user interface.
Tree List View in Halo 2 Guerilla: The tree list view was added by Bungie for Halo 2 for Xbox for easier tag browsing. The functionality of the tree list view was expanded so that any tag that is opened has its directory added to the tree list view if it does not already exist.
Undo Command in Halo 2 Sapien: One of the most requested features from users, an Undo command was added to Halo 2 Sapien, and it works on the most commonly used commands, including object creation, deletion, movement, and rotation.
Autosave in Halo 2 Sapien: You can set up autosave to save your hard work automatically instead of manually.
Loading Screen and Progress Bar: A loading screen and progress bar have been added to display status of the level load and output in Halo 2 Sapien.
Game Type Error Checking of Netgame Flags: An error and warning box has been added to let you know when the level does not meet the requirements for a particular game type.
Most HEK users are accustomed to installing the editing tools into a directory completely separate from the main game to prevent mixing their own files with the main installation of the game. With the Halo 2 Map Editor tools being official products that need to run within the confines of the Windows Vista limited user environment, much of that workflow had to be changed.
Because Halo 2 supports custom multiplayer maps out of the box, it is expected that most users will install the Map Editor tools into the same directory as the game itself. It's also assumed that most users will choose the default directory for installation, which is C:\Program Files. Because the normal user account level in Windows Vista cannot write files into that folder, the Halo 2 Map Editor tools have been adapted to work across multiple directories.
It is recommended that a user set up a working directory elsewhere on the hard drive. A predefined or default location is the user's Documents\Halo 2 folder, which is created automatically the first time one of the Map Editor tools is used. All of the custom files a user creates for Halo 2 should go into this working directory, usually in data and tags folders. When looking for a file referenced by a tag within a custom working directory, the Halo 2 Map Editor tools will first look elsewhere within that working directory. If the file is not found, the predefined Documents\Halo 2 working directory is then checked. If it isn't found there, the Halo 2 Map Editor tools will look for the file among the original Halo 2 assets.
It is perfectly acceptable to have multiple working directories. Files in one directory will not interfere with files in another. This also means that a custom .shader file in one working directory won't be found by tags in a different working directory; the sole exception is the predefined Documents\Halo 2 directory.
Because the user's Documents\Halo 2 folder is visible from all custom working directories, it is a generally handy place to store commonly used assets like custom texture packs.
Halo 2 for Windows Vista and Halo CE File and Directory Differences
Besides the directory structure differences listed above, the directory structure for Halo 2 can be one of the most complex aspects of Halo 2 editing. In the HEK, custom maps and their associated assets for both source (data) and compiled data (tags) were self-contained within the individual level directories.
In Halo 2 Map Editor, assets (both the source files and the tag files) are much more scattered around than what end-users may be accustomed to with HEK editing. The individual level directories for source files (data\scenarios\multi\mapname) only contain the level .max source file and exported .ass file (as well as some other minor files). The individual level directory for the compiled level tags (tags\scenarios\multi\mapname) contains the .scenario file, .scenario_bsp file, .scenario_structure_lightmap file, and.bitmap file used for the lightmap.
All other files such as image source files (data\scenarios\bitmaps\multi\mapname), compiled .bitmap tags (tags\scenarios\bitmaps\multi\mapname), and .shader tags (tags\scenarios\shaders\multi\mapname) are located away from the main level directory.
Some tag assets such as .scenery objects may be in different areas than you’re used to.
In general, it is highly recommended that you explore the contents of all the tag folders to fully familiarize yourself with the assets available in Halo 2.
Photon Mapping: New lighting results in more robust, accurate, and visually stunning maps. Use a less-intensive lighting setting when testing map changes.
Material System: The improved material system has more options and flexibility. Shader file extensions no longer determine shader type. Shader templates define shader material and are referenced by the unified .shader file. Users now have more options for Shader templates and improved data fields for shader files in Halo 2 Guerilla.
Instanced and Detail Geometry: Instanced and detail geometry allows the creation and placement of geometry that does not have to be stitched into the world.
Courtesy of Halo Maps website www.halomaps.org
Halo 2 Vista Maps