Breakable Glass for CGF / AQ2

Would you like to bust through windows to surprise your opponent? Is it cool to take out both your target and the pane he feels safe behind? Does the sound of breaking glass get your adrenaline pumping?

My bots answered "yes, yes, and yes". They consider breakable windows essential for single player AQ2 (and for some LAN AQ2). So Tekminus, doing the test maps, and I, doing bots and additional coding, sat down and started breaking stuff.
Have a look at the results...

This breakable glass allows you to:

• jump through windows
  you need to have sufficient speed and approach the pane more or less frontally; you receive 15 damage and continue to bleed [see top 3 images above]

• fire through windows
  Take out your opponent through the glass. When using the sniper rifle or the shotguns, the pane will always break. For bullet weapons (handgun, machine guns) the chances are about 25% percent for the glass to break. In all cases, glass fragments erupt from the pane. Bullet effectivity is not reduced (just made fancier) [see second row of images]

• jump kick window (or your opponent through the window)
  When you lack the speed to jump through, your repertoire of jump-kicks will do to break the window; however, you incur the 15 damage and bleeding. Skilled Action gamers will soon use their opponents to break the glass and receive that damage. [see third row, image 1 & 2]
• grenades and windows
  Hand grenades will easily break windows: first, when you throw them through the glass to surprise your friend. And second, when the grenade explodes and blasts away any nearby windows still untouched.
• knifes
  Knifes have a harder time in dealing with glass. Thrown knifes will happily bounce from glass. The sole way of destructing a window with a knife is to slash it (and you won't receive damage from that).

For normal gamers, that's about all you have to know about breakable glass. Except for one thing: at this time, none of the official Action Quake2 maps features breakable glass, except for office3. However, mappers can add breakable glass easily, and without endangering normal Action Quake2 performance on their maps. So start requesting breakable glass from your favourite mappers today!

(NB. Breakable glass has been present in the early days of Action Quake (at the time of version 0.47). It was taken out, because the amount of glass fragments (and the corresponding broadcast messages) tended to crash servers.
This time, utmost care has been taken to keep the amount of glass fragments and messages within server specified limits. In addition, the breaking of glass has been fully integrated with all of AQ2's features: different weapon types, damage, running, jump kicks, bullet holes, blood splats, grenades, and teamplay rounds.)

For server ops and mappers, there two more important things:

1. breakable windows are as optional to the server as are bullet holes, blood splats and ejecting shells. By default, they are not enabled. Set the cvar "breakableglass" to "1" to enable breakable glass.
   Breakable glass will cause an amount of lag comparable to bullet holes; breakable glass therefor is not a realistic option for internet games. It definitely is a good option for CGF bot games, and for some LAN games as well.
   Note that the current special FX such as bullet holes, blood splats and shells mainly have a cosmetic purpose; however, breakable glass really affects the game.
   Broken glass will be reconstructed for every round of team play, ensuring maximum recycling of this material.
   The total amount of glass fragments (dynamic entities) can be controlled via the cvar "glassfragmentlimit" (default value "30").

2. As mentioned above, mappers can add breakable glass without endangering the map's performance under normal Action Quake2 deathmatch and team play. That's because, by default, all func_explosives are removed in multi-player mode. Only when breakable glass is enabled, solely those func_explosives that contain transparent surfaces are retained.
   To add a breakable glass brush, you have to make it a func_explosive. Then make sure the textures are set to be transparent. Make sure the brush has health (health > 0), and doesn't cause damage (dmg = 0). Make sure you add a target_speaker entity that plays the (standard Q2) breaking glass sound (brkglas.wav). That's it.
   (For these glass func_explosives, the new code will automatically spawn a a trigger field detect player movement; you don't need to add additional triggers).

Special credits: tekminus, for crafting the first AQ2 test maps so my bots and I could exercise the breaking of glass.

Breakable Glass Downloads

• ActionQuake2 1.52 (official version)
• latest CGF version (1.51 + glass fx + bots)
• additional code and modified AQ2 1.51 files
  (C and C++ versions included, delta info in header file)
  [100KB, Jun 12 1999 (knife slashing present)]
• small one-on-one test map by Tekminus
  (includes required sky and textures (from urban3))
  [333KB]

William