Tutorials

quake2 - light, light_mine1, light_mine2, info_null, func_timer, _minlight


Ask any level designer what the most time consuming part of level design is, and they will most likely answer: lighting. The fact is, lighting isn't that difficult in implementation, but rather in choices of lighting, and the amount of options available. We'll try to break down the choices here.

Lights, since they are just point entities with working defaults, are among the easiest entities to add, but the actual method varies from editor to editor, so check the docs for yours.

Now, on to the good stuff. Here are the flags and fields, and their uses:

LIGHT

This is the brightness of the light. Default is 300. The fall-off distance of the light is proportional (the brighter the light, the further it shines.)

In order to change the light value, simply add a key of "light" with the desired keyvalue.

One thing worthy of mention. Light entities differ from lit surfaces, in that the amount of light that a surface emits is dependent on the size of the face, whereas two light entities with the same "light" keyvalue will always emit the same amount of light, regardless of color. (which is why software Q2 always looks so bright)

_COLOR

(Note, a value prefixed with an underscore (_) means that the key will be ignored if the default is not applicable. This is why "color" works here as well. It's good practice to always include the underscore, even if it works without it.)

This is the color that the light entity will emit. The actual color is determined by a set of three numbers between 0 and 1, representing red, green, and blue, respectively. The _color values are proportional, meaning that a value of "0.1 0.1 0.1" would give you exactly the same thing as "1 1 1", and "0.5 1 1" would give you the same as "0.25 0.5 0.5"

Example:
"_color" "0 0 1" would emit blue light in gl
"_color" "1 1 1" would emit white light in gl
"_color" "0.5 0.5 0.5" would emit white in gl.
"color" "1 0 0" would emit red light in gl, but kick out a "color is not a field" warning in software. (moral: use the underscore)

The color room in the [example .map] demonstrates mixing of colors, as well as how bad too much color can look.

STYLE

The style key determines whether or not the light will be a dynamic light, and if so what pattern it will follow. The default is 0 (static).

Here are the values, and their patterns. 'a' represents total darkness, and 'z' represents double brightness. 'm' is normal brightness (nabbed from the gamex86 source):

  1. FLICKER (first variety)
    "mmnmmommommnonmmonqnmmo"
  2. SLOW STRONG PULSE
    "abcdefghijklmnopqrstuvwxyzyxwvutsrqponmlkjihgfedcba"
  3. CANDLE (first variety)
    "mmmmmaaaaammmmmaaaaaabcdefgabcdefg"
  4. FAST STROBE
    "mamamamamama"
  5. GENTLE PULSE 1
    "jklmnopqrstuvwxyzyxwvutsrqponmlkj"
  6. FLICKER (second variety)
    "nmonqnmomnmomomno"
  7. CANDLE (second variety)
    "mmmaaaabcdefgmmmmaaaammmaamm"
  8. CANDLE (third variety)
    "mmmaaammmaaammmabcdefaaaammmmabcdefmmmaaaa"
  9. SLOW STROBE (fourth variety)
    "aaaaaaaazzzzzzzz"
  10. FLUORESCENT FLICKER
    "mmamammmmammamamaaamammma"
  11. SLOW PULSE NOT FADE TO BLACK
    "abcdefghijklmnopqrrqponmlkjihgfedcba"

12-31 open for modification

32-62 reserved by QRAD3 for switchable light styles, and 63 is reserved for testing

In order to make a dynamic light, simply add a key of "style" and the appropriate value. (ex: "style" "5" will make a pulsing light.)

INFO_NOTNULL

- a target_laser will only shoot in a horizontal or vertical direction. However, if you want a laser to shoot in other directions then you're going to have to have it shoot at a target. This target must be an info_notnull.

- this is where the turret_breach will be aimed at. (See
turret).

- but, it can also be used as a teleporter_destination. Instead of using the destination entity you can just use this Info_notnull. The advantage is that the player will no longer be teleported onto that little destination platform, but can now be teleported into mid-air:)

TARGET/INFO_NULL/SPOTLIGHTS

A light entity can only target one thing: an info_null. What happens when you target an info_null? a spot light happens. (woo) Personally, I dig spotlights, and use them a lot. Here's how you do it.

Create a light. Give it a "target" key, and a keyvalue (we'll use "spot1".) Create an info_null at the place at which you want the spotlight to point. Give the info_null a "targetname" key, and keyvalue (again, "spot1".)

Now, what if you want a wider spotlight? Well, that's why we have...

_CONE

The default _cone value is 10. The higher the value, the wider the spot. To use it, add the "cone" key, and the desired value to the light entity.

Switchable lights

Let's say we wan't a light to be turned on or off by some other event (be it a button, trigger, etc..) What we need to do in this case, is to set up the triggering event (in this case, a func_button,) and give it a "target" (we'll use "lt1".) Now, we need to create a light, and give it a "targetname" of "lt1". We now have a light that turns off when we hit the button. If you would like the light to turn on when you hit the button, set the start_off spawnflag for the light.

func_timer

Now we'll move on to the func_timer entity, and how we can use it to create a blinking light that looks a bit more random than the predefined styles.

What exactly is it and what does it do? A func_timer is just that. A timer. When the time is up, the timer triggers all of its targets, and then starts over. This has a wide range of uses, such as a door that opens 30 seconds after another door, or a light that turns on 2 minutes after you enter a level. I this case, we're going to use it for a flickering light that starts on, and starts flickering when we approach it.

First thing we need to do is add a light. Give the light a "targetname" (we'll use "flic".) Now create a func_timer, and give it a "target" key with the value "flic". We want the light to turn off and on every half second, so we'll use the "wait" key, and give it a value of "0.5". Now, since we wan't it to look like a random flashing light, we'll use a key that's pretty damn neat. The "random" key. Give it a value of "0.3". This means that the light will toggle every .5 seconds, +/- .3 seconds. So the flashing will vary from .2 seconds to .8 seconds.

Now, let's say we want the light to start flickering 1 second after the timer is triggered. Why? because I only have two keys, and one spawnflag left to explain on this one, and this is one of them. What we need to do here is make a key called "delay" and give it a value of "1".

Now create a trigger_once, and target it at the func_timer.

If we wanted the timer to start as we entered the level, we would set the "start_on" spawnflag.

The last key for func_timer is "pausetime". Pausetime is the amount of time, in seconds, that the timer will wait before the first time it starts. pausetime needs start_on to be set. If you have a "delay" of "10", and a "pausetime" of "20", the timer will fire 30 seconds after you begin the level. If it's turned off after that, and turned back on, it will wait 10 seconds.

light_mine1 and light_mine2

These 2 entities are simply predefined lights that are the lights that were used on the mine levels in quake2. They act like normal lights they just have a predefined shape. Here are pics of them.

mine_light1  min_light2

NOTE: If you want to rotate a light_mine (1 or 2) you have to give it an "angle" key.

_minlight

_minlight is a very strange key value pair that can be used with certain entities like func_door, func_button, func_rotating, etc, etc. Basically any visual entity except the item entities. What it does is makes the object glow. Lets say you have a very dark room and there is a button the player has to press but it is so dark that the player is not going to be able to find it. Well, this is where _minlight can come in very handy. Select the func_button entity and give it a key value pair of _minlight and a value of 1. This will make the func_button glow a faint white so it will be more visible.

The glow from _minlight does not make the surronding area any brighter, just the object that has the _minlight value.

The values for _minlight should be between 0 and 2. I have not noticed any difference with exteremly high values. 2 seems to be the max.

-GrrandMaMa

You can download the [example .map] here. Also if you have any problems or need some help please post to the discussion board.

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HTML Design, original concept of rust by Shane 'Fishman' Sherman rust is 1998 by Shane 'Fishman' Sherman and Martin Ka'ai Cluney(GrrandMaMa). This particular tutorial was created by GrrandMaMa and belongs to him. Quake and Quake2 are trademarks of id software. All rights reserved.