Quake 2

Jump pads in Q2? You betcha! - David Hyde & Mad Dog

The "angles" key/value pair

OK, this is a long story, but you goons are required to read the whole thing... that's the price you pay for cool information. My Tarot teammate and spiritual advisor Monsto Brukes wanted to simulate Q3 jump pads in Q2 for map testing purposes. Tarot's bit_twiddling nerd guy (that's me) opened up the Q2 source and started to plug in an elevation value. But wait... he found that trigger_push code refers to the "angles" key... but that's not right he says... trigger_push just uses "angle". Well it turns out id didn't trust you mapper goons to be able to do a little simple trigonometry, so they published the input for trigger_push as "angle" only, but the code does not have that limitation.

The "angles" values are pitch (up/down), yaw (left/right) and roll (fall over). If "angle" is specified for an entity, then the code automatically sets "angles" to 0,angle,0... and these values are used for the entity. But what happens if instead of specifying "angle" in the .map file, you set the three "angles"?... heh heh... you know the answer, don't ya? And all it takes is a little math to translate those angles into movement directions... but not to worry, Tarot's bit_twiddling nerd has done that for you. The translations performed by the game source end up making a positive pitch down from horizontal. Yaw is unaffected by this, so you'd use the same angle you've previously used for the angle key. And roll is ignored for trigger_push, which is a shame, really... it would be nice to have a trigger_push that made you do flips. Anyhow... quick example, and I'm sure you can take it from there. Say you want the trigger_push to push you up 60 degrees from horizontal and to the west. Set "angles" to _60 180 0. That's it.

So how do you go about using this info in your editor? If your editor allows you to enter user_defined keys (qED, QERadiant, QuArk), you're all set. Just enter "angles" for the key and "<_pitch> 0" for the value. If you're using Tread, open up quake2.gdf, find trigger_push, and enter the following below the "angle" line:

def_key : string : "angles" : "pitch yaw roll" : ""

If you're using WorldCraft, Mad Dog has already done the work for you... get his new .fgd file. If you're using Qoole, stop. (ed. I’d have to agree.)

One qualifier that could foul this up for you: If your editor forces an "angle" key to be written to the .map file, "angles" will still work as long as it occurs after the "angle" definition. So if you try this and you get the same old trigger_push behavior, open up your .map file in a text editor, find the trigger_push, and delete the "angle" line.

The syntax for an 'angles' keyvalue is:

"angles" "pitch yaw roll"

Pitch can be any number from _90 to 90; negative numbers "aim" up and positive numbers "aim" down. Yaw can be virtually any positive number, generally 0_360 (this would be the same value one would typically use for 'angle'). Roll can be any number from _180 to 180; this affects the "canted" view one can achieve with an info_player_intermission. Depending on the entity, a "roll" value of anything other than 0 can yield no result, an interesting result, or a result you want to avoid.

Some example entities by way of explanation:

• Ammo - Ammo need not lie flat. If you want to put a box of ammo on a tilted floor, or simulate an item amid a jumble of other debris you can. Note that the bounding box of the ammo does not change position or orientation, so you may need to work in a wedge_shaped mist brush in there to get the visual effect just right. Giving values to all three angles is fine.
   
• Player starts, deathmatch starts, teleporters - DM spawn points and teleporter/dest platforms can be canted just like ammo. However the 'angles' value translates into the direction the player looks when he spawns. So if you want the player to spawn up on a high ledge, looking down on the action, you could give the spawn point an 'angles' value of "45 0 0", for example. Even if the player has freelook off and lookspring on it works fine. I strongly advise against using a "roll" value of anything other than 0, since the player gets stuck with the canted view. Until he hits a teleporter dest which straightens him out anyway. Unless of course you want to simulate drunkeness.
   
• Strogg ships, Vipers - Simulate diving or launching ships. Or a crashed misc_bigviper. Looks cool; use all 3 values. Advise the use of a playerclip brush to avoid weird clipping problems with the misc_bigviper model in the game.
   
• Banner - All 3 values work, but the appearance is odd; so "roll" has little value __ but a slight "pitch" effect could have its place I suppose.
   
• Monsters - Good for a laugh. Give a monster_soldier an 'angles' keyvalue of "60 0 0" and he "swims" on the floor. Too bad monsters drown in water. Death animations can be even funnier.
   
• Target_blasters - Want a blaster that shoots up or down at an angle? No problem. "Roll" values don't matter. Works with lasers too, if you don't want to bother with an info_null. And it works with the target_splash too.
   
• Doors and buttons - This is very very cool. You can have multi_piece doors that move up/down at angles, and buttons that recess properly into angled consoles. Figuring out 'lip' may be a problem; I haven't experimented but I suspect that the game uses either a horizontal or vertical orientation for calculating 'lip'; so I would avoid using _45 and 45 for "pitch", so you can get predictable results. Again, "roll" doesn't matter.
   
• Weapons, keys, armor, etc - Spinning crap seems to ignore 'angles'. Too bad.

Anyway these are some ideas. In order to use the 'angles' key properly in Worldcraft, you should set 'angle' to '0'; this removes the 'angle' key from the .map file. My .FGD prompts you for "pitch yaw roll" for entities which can make use of "roll", and it prompts you for "pitch yaw 0" for entities which can't.

The team was so fired up about this that we built a fun DM map for you guys to check out. We started out making a small tutorial sort of thing, but it got out of hand pretty quickly and turned into the real deal:
You can download the map here (589Kb).
The map is an r_speeds hog, so if you don't have a 3D card please don't bother. The .map file is included.

You can download Mad Dogs .FGD here.

David Hyde:

• Home Page
• MapSpy 1.0
• GenSurf 1.7
• Tarot Game Development

Mad Dog:

• Home Page

Note: This tutorial was copied almost verbatim from the Rust Forums (ed. note: the OLD Rust forums, that is - Merl) with minimal editing by raYGunn. It is also interesting to note the discovery of the usage of the angles key by the authors was independent and for different purposes.