Demo Recording

Overview

A demo in City of Heroes is an in-game recording made via the /demorecord Slash Command. The demo feature allows you to make recordings of your gameplay and use the game engine to play back those recordings. The recordings created this way are not actual video documents, but simply text files with a record of all the commands, models, effects, and animations that tell the game engine how to render the recorded demos. Because the demo files are just text files, demo recordings can be edited with any text editor, or with player-made tools specifically designed to manipulate demo files. This gives you the ability to modify demo recordings (or even create them from scratch) to make custom "movies" for playback via the game engine, allowing situations and events which may not exist during actual play. The demo playback can then be captured with a video capture tool and then further edited to customize your film, and to share it with others.

How To Record A Demo

To begin a demo recording, type the following on the chat command line:

/demorecord "demo_name"

Where "demo_name" is the name of the file you wish to save the demo name as. Do not use quotation marks in the actual name. The demo name should be all one word and should not contain any punctuation (hyphens and underscores are acceptable, spaces should be avoided). For example:

/demorecord coolinvasiondemo1

To stop the demo recording, type the following on the chat command line:

/demostop

Please note that the demo will also automatically cease recording if you zone, such as when exiting a mission. If you have recorded a very large demo (either lengthy or one featuring a lot of in-game activity), the game may pause very briefly when issuing the /demostop command. It may therefore be advisable to wait until after the big boss fight to stop your demo recording.

The recorded demo will be saved to your City of Heroes directory in the "client_demos" folder. The demo recording file will have a suffix of "cohdemo". In the example used above, the "coolinvasiondemo1" file would be found as follows:

\city of heroes\client_demos\coolinvasiondemo1.cohdemo

Playing Back A Demo

Recorded demos can be played back multiple ways. Two of the more common methods are either to create a shortcut to the cityofheroes.exe application and modify it to launch a demo or to use a player-made application specifically to play back demos.

Playback Via A Windows Shortcut

Method 1

To play back a specific recorded demo via a Windows shortcut, use the following steps:

• Locate your City of Heroes directory and make a shortcut to cityofheroes.exe on your desktop (or wherever you prefer).
• Right click on the shortcut and select Properties.
• Within the Target box you will see the command line: "C:\Program Files\City of Heroes\CityOfHeroes.exe" (the directory path may be different if you did not install City of Heroes in the default directory).
• At the end of this line, add a space, followed by -demoplay your_demo_name (where your_demo_name is the name you gave the demo).
• For example: "C:\Program Files\City of Heroes\CityOfHeroes.exe -demoplay coolinvasiondemo1"
• Exit Properties.
• Double-click the shortcut you just created. This should launch the game client into demo playback mode and play the demo you specified.

Note that when playing back a demo via this method, the demo you specify in the shortcut properties must be in your client_demos folder.

Method 2

Similar to above, however if you leave off the your_demo_name in your shortcut, you can drag and drop any *.cohdemo file onto it and that particular demo will play without need to specify the file name in the shortcut.

Playback Via A Demo Launcher

An alternative to playing back a demo via a shortcut to the game client is to use an application specifically designed to play back a demo (the application still does this via the game client but handles all of the operations required for demo playback automatically). Many people find this less cumbersome than launching via a modified shortcut or other method. Another advantage of using a demo launcher is that is may also perform automatic functions to "fix" certain aspects of demo playback if there are known playback issues resulting from playing the demo directly.

Probably the most popular demo launcher is Zloth's CoH Demo Launcher program.

Uses For Demos

Recording Game Play

The most straightforward use for demo recordings is to capture some segment of game play for later viewing, sharing, or editing. Alternatively, there are stand-alone video capture applications (such as FRAPS, for example) that can directly record graphics displayed on your screen to a video file as another means of recording game play. There are both advantages and disadvantages to using the /demorecord function over other methods of recording game play.

Capturing Screenshots

Demos can also be useful for capturing Screenshots. If you have a particular screenshot in mind that requires specific timing, it can often be difficult to capture that specific moment during actual play. If you plan in advance to record a demo during the time where you wish to capture a particular screenshot, you can play back the demo and use this to capture the screenshot.

At its simplest, this can be done simply by playing back the demo and trying until you get the right moment. However, the available demo functions also include options to export the playback of a demo to a series of image files for each frame displayed, as well as the option to adjust the speed of the demo by specifying the frames per second (FPS) of the playback. Between these two options, you generate very precisely timed screenshots. The disadvantage of this is that exporting the playback of the demo to a series of image files can use a significant amount of disk space.

Further, the ability to edit and customize demos gives you the capability to produce screenshots of situations or events than can not be produced during actual play.

Please note that the game user interface (UI) is not displayed during demo playback. If you require a screenshot that shows the UI, this can not be captured from a demo.

Creating Custom Movies

Perhaps the most interesting application is using demos to create custom movies, or Machinima, using the City of Heroes game engine.

As mentioned, a recorded demo is saved as text file, rather than a standard video file. This text file contains all the commands required to instruct the game engine how to play back the recorded demo. This includes such information as what character models to display, special effects, character animations, character and object locations and orientations, character movements, camera angles and movements, and more. All of this information can edited, changed, deleted, or added, and requires only a text editor (and a reasonable understanding of the appropriate demo information) to do so. This process is often referred to by players as Demo Editing.

An edited demo can then be converted to a standard video format (AVI, MPG, WMV, Quicktime, etc.). This can be done using a video capture tool such as FRAPS or by using demo playback options to export each frame of a demo to an image file (which could then be further manipulated if desired) and then converting that series of image files into a video. Once captured into a standard video format, video edit tools such as Windows Movie Maker can then be used to further customize the captured video with such additions as titles, scene transitions, voice-overs, and so forth.

Overall Demo Editing is a powerful tool for being able to create highly original movies using the City of Heroes game engine. To best understand what can be accomplished by editing demos, it may be useful to view some examples of movies created by this process. The following are just a few examples many excellent and creative player-made movies created with Demo Editing:

• CoH Thank You at YouTube
• The Dance Gun at YouTube
• The Operatives - In The End at YouTube

List Of Demo Commands And Switches

• /demorecord <demo_name>

Starts a demo recording with file name demo_name

• /demostop

Stops a demo recording

• -demoplay <demo_name>

Plays client_demos\demo_name.cohdemo

• -demofps <FPS>

Renders demo at the specified frames per second (FPS); will not skip frames; changes the apparent speed of the demo playback

• -demodump

Saves ("dumps") all frames of demo as JPEG images to client_demos\screens\demoname

• -demodumptga

Saves ("dumps") all frames of demo as TGA images to client_demos\screens\demoname

• -disable2d

Hides all text effects (player chat, floating damage/healing text, etc.)

• -fullscreen <fullscreenflag>

fullscreenflag = 0 for windowed, 1 for fullscreen

• -screen <width> <height>

Set the window size or screen resolution to the specified width and height

• -demopause <milliseconds>

Stops at milliseconds

• -demosize?
• Game Client

External Links

Zloth's Screenshot and Demo FAQ