A COMPREHENSIVE LIGHTING TUTORIAL

"Machismo"
cool_machismo@yahoo.com

INTRODUCTION

This is a medium sized tutorial that will cover all the aspects of lights. Basically all you will need to know about lighting in the beginning and intermediate stages. Lets be off then!.

LENS FLARE

Lets see the various simple steps that are involved in making a light display a flare:

1. First load a suitable texture package. For now load up GenFx.utx which has the best flares. Now from under the LensFlar subsection just choose a suitable texture.
2. Place a single light in your level where you want it to display a flare.
3. Now just go to that lights properties and set the following:

1. First and foremost go to the lighting subsection and set bCorona to True.

2. Now go to the display section and scroll down to Skin. Since you have already chosen the lensflare that you want to use just hit the use button. If you did not select a lensflare previously, hit the 3 dots in the skin line and when the texture browser opens choose the appropriate lensflare and then hit use.

3. Now if you left it as it was the lensflare would be way too big. Still under the display section set bDrawScale .10 - which will reduce the size in which lensflare will be drawn. You need to set this amount depending on the situation in your level, but generally speaking .10 is a very comfortable size.

4.  Ok, all you need to do now is rebuild the level to see the lensflare in it.

Lensflare makes your level look stylish and professional. But make sure you give it a light source, i.e. put it in front of a light texture to make it look more convincing.

LIGHT PROPERTIES / LIGHTING

Under a lights properties, when you expand lighting, you get to fiddle around with all lot of very cool settings I'm going to show you how to make use of all of them. All the following that is:

LIGHT COLOR

I have already discussed how to make colored lighting in the UnrealEd2 Introduction. Its really simple and I don't think I need to say any more. Basically the light color is determined by the Hue and Saturations values which you can pick from the standard windows color choose. To choose the color of a light just select light color and hit the color button. This will open the windows color chooser where you can select the type of color that you want. my suggestion is that you first select a base color that from under basic colors and then move the crosshair in the light gradient and you will see the actual color being reflected in the color solid box.

LIGHT RADIUS (IMPORTANT)

The importance of this setting cannot be under emphasized. I think next to light color this is the most important setting. The light radius amount will determine how large a area that, that particular light will affect. Generally speaking a light radius of 64 is too high an area. The best way to determine the radius that a light has is to turn on radii view in all the 2d and the 3d view (to do so right click on the top of the view and from the actors menu choose radii view).

In the picture above you can see the tunnel that has been highlighted and the lights and their radius also highlighted - they have a radius of only 5 - if I had put a higher value then the light would have flooded the other areas making it difficult to determine the light source so that the others rooms would be affected for the worse. This is a case where instead of having to change the light radius of only a few lights, you will necessarily have to change the light radius of all the lights and there will be only a very few lights which you will leave with the default 64 radius.

NOTES: If you experience a case of your lens flare disappearing on you this is the setting that you will need to change. Also when lighting outdoor levels, just use a few lights with their radius set to a large amount like 175 instead of using a lot of lights which will make the level look ugly. This is the technique the pros used.

FOG

You will use the last three settings from under lighting , i.e. VolumeBrightness, VolumeFog and Volume radius. To make a light display fog is very simple.

1. First seal the room where you want the fog to appear into a complete zone using the zone portal brush (if you don't know hot to do this you can read the Miscellaneous Zone Class tutorial here to find out).

2. Place a normal zone info actor (from under info - don't expand zone info like you do for other subclasses). Under the zone info's properties expand zone info and set bFogZone to true.

3. If you want to set the color of the fog you will need to set it under the zoneInfo's properties itself. Under the zone info properties just expand zone light and you will see a entry called FogColor, just hit the 3 dots at the end and the standard windows color choose will appear.

4. If you want to set the radius of the fog or how far the fog will be seen you can set the amount under fog distance.

5. Now we come to the lighting part of the tutorial. Just add in a single light in the room where you want the fog go to its properties and expand lighting. You will just need to set VolumeBrightness, VolumeFog and Volume radius which determine the brightness of the fog, how thick the fog is and the amount of distance it is drawn respectively.

Since fog is one of those effects that can slow down your level use it sparingly.

SPECIAL LIT

The bSpecialLit value of a light allows you to affect the surface of a specific texture without affecting the surrounding area. This means that you can have a texture surface lit with one color while the rest of the area is lit by another color.

To make use of this feature first go to the surface property (select a texture and hit F5) of the texture that you want to have specially lit (for example you can go to the surface property of a light texture to make it seem differently lit from the surrounding area. Under the textures properties in the flags tab just check special lit. Now all you need to do is place a light (or lights for that matter) nearby go to its properties and under lighting set bSpecialLit To True. You may also need to change the LightRadius for it to be displayed properly.

In the picture above the light texture is Xlight2 from the UTtech1.utx texture package (its white in color). I set its surface properties to special  lit and place two lights in front who were also special lit.Notice how the room is blue in color but the light is purple.

LIGHT TYPE

Most of the light types you will find are pretty self-explanatory and I will not be able to show pictures of them without doing an animation. But use the light types sparingly as they tend to slow down levels drastically, i.e. dynamic lights (lights that basically u know ..... do stuff) slow a level down. its better to give this to a single or few lights instead of something like 50 lights - that would be asking for it :). Note to see most of these lights in action you will need to turn on Real Time Rendering by hitting the joystick button in the 3d view. Try the types one by one in your level to get a feel for it. but anyway here's a list of light types and of what they do:

1. LT_Pulse - Heavy disco style pulse - looks like the light is just being turned on and off by itself.

2. LT_Blink - Reminiscent of those bulbs that seem to be short circuited and about to blow at any second.

3.  LT_Flicker - Heavy blink.

4. LT_Strobe - Disco Strobe Lights Effect.

5. LT_Pulse - Softer pulse than the previous one.

6. LT_TexturePaletteOnce - (See Below) Does the same as the below one only once.

7. LT_TexturePaletteLoop - Use this in conjunction with the Special Lit technique described above. In the above example after going through the special lit stuff if I had turned the Texture Palette Loop effect on the light texture would have alternated between purple and white lights. It will give only the texture a sort of subtle pulse.

LIGHT EFFECT

Again these tend to slow a level down like anything (most of the effects though not some). Another list of the various light effects and what they do:

1. LE_TorchWaver - Shimmery torch like effects. looks like the textures that the light effects have a fire drawn on it.

2.  LE_FireWaver - Heavier torch waver effects.

3. LE_WateryShimmery - Looks like the texture which the light touches is reflecting water - great to use in rooms that have pools in them.

4. LE_SearchLight - exactly like a constant search light used in prison camps.

5. LE_SlowWave - Soft Rippling waves being drawn on the textures within the light radius.

6. LE_FastWave - Much faster waves being drawn.

7. LE_StaticSpot - Displays the light like a powerful, search beam focused on a single area.

8. LE_Shock and LE_Interference - Got to be seen to be believed.

9. LE_Disco - Huge revolving disco type lights.

10. LE_SpotLight - Like StaticSpot.

11. LE_NonIncidence - The difference between a LE_None (no light effect that is and LE_ NonIncidence is very subtle. The none effect casts light in a radius. Thus you can literally make out the radius stretching out. Whereas in LE_Nonincidence the light is cast uniformly without a room having a brighter center and darker corners (assuming that the light is place in the center of the room.

12. LE_Cylinder - Whereas the static spot and spotlight cast a light directly in the face direction the LE_Cylinder effect makes it look like the light is being cast down in a straight cylinder from the light source. The light radius must be very small like 4 or 5 or depending on your level to achieve this effect.
    
    Note: The same effect can be achieved with static spot.

13. LE_Rotor - Like the blades of a heli rotating in the room.