Portal 2

Portal 2

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PsychoBR 8 May 17, 2012 @ 5:15am
Tutorial Demo Tools - Recording and playing
Portal 2 has an internal tool that records the movements of your gameplay. To be shown later, like the replay of a racing game. It is easy to use and very useful to show others users the way you solve a puzzle.


1. Put .DEM file in "...Steam\steamapps\common\portal 2\portal2".
2. Press Shift+F2 to open Demoplayback and open file.
Or in game console put "playdemo NAMEFILE".


1. In game console put "record NAMEFILE" to start recording.
2. In game console put "stop" to stop recording.
3. The .dem file are saved in "...Steam\steamapps\common\portal 2\portal2"

*The console must be enabled in game options
*If the map is changed, the .DEM files recorded before the update does not work anymore. Unless the old map is in the cache folder Portal 2.

More info in Valve Demo Recording Tools:


1. Subscribe this map.
2. Download the Demo record files[dl.dropbox.com] for this map.
3. Follow "How to Play a demo file" instructions above.

Good recordings,

// Play my Map Pack: Damn Turrets.
Last edited by PsychoBR; Aug 6, 2012 @ 8:33am
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Showing 1-5 of 5 comments
FutureGameDev 17 Jun 22, 2012 @ 10:27am 
I hope this works...I can't wait to try.
RaVeN 10 Jun 25, 2012 @ 1:58am 
Hmmm I avoided theses console commands, or the “startmovie FILENAME avi” for windowed mode, because I didn’t want to have to mess about converting .dem files to .avi.

However I just had another look into the issue and it seems that the primary cause of this issue is not Fraps at all - it’s making sure the playback and recording default formats in Windows are both the same i.e. 24 bit, 48000Hz (Studio Quality). Or that the audio part of the movie is longer than the video and needs ‘resizing’ to match the video part (although this may simply be caused by the same Windows audio issue).

Later today when I have time I will install 64-bit fraps and upload the video to YouTube etc. and let you know if it works!

PsychoBR - thank you for your well-formatted and informative reply, I will check out your workshop files eventually when I have the time. Thank you :)
Portλl Nerd 45 Oct 18, 2012 @ 1:59pm 
thanks, this should really help me out
HOOK 37 Nov 9, 2012 @ 9:39pm 
Possible addition for anyone doing challenge mode or just wants to restart levels quickly without redoing demo commands. You can use this:
bind r "stop;restart_level;record my_demo"
This is helpful in challenge mode because recording a normal demo will automatically add .4 seconds to your time. As a person who has been .01 seconds from people in portal 2, this is very helpful.
Cant find the demo anywhere, I have mac
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Date Posted: May 17, 2012 @ 5:15am
Posts: 5