Sectors have a number of attributes that can determine their appearance and provide some special effects. This section describes these attributes. See [UDS:4-9] and [UDS:4-9-1] for full details.
Lighting:
The brightness of a sector is determined by it's light level, ranging from 0 (pitch black) to 248 (very bright). Roughly speaking, levels from 192–248 tend to be subtle brightness changes, levels from 128–192 are shadow-like, while dimmer levels provide varying degrees of darkness. In these darker sectors, things further away are harder to see, with the visual range being determined by the light level. Levels close to zero will mean the player will not be able to see anything, even something directly in front of him!
Lighting Effects:
There are a number of lighting effects available through the use of the sector special attribute.
1) Blinking: The various blink effects will cause the light level to blink regularly between the specified light level and the lowest light level of any adjacent sector. If the adjacent sectors all have the same light level, or there are no adjacent sectors, the lowest light level of the blink will be pitch black.
2) Oscillating: The Oscillate effect will cause the light to smoothly vary between the specified light level and the lowest light level of any adjacent sector. If the adjacent sectors all have the same light level, or there are no adjacent sectors, the oscillate effect will not work.
3) Flicker: The same as the blink effect, except that the on and off times are random.
Lava and Acid – Damage Sectors:
When a sector is given a damage sector special, the players will sustain damage periodically while they are standing in the sector. This is typically used with "Lava" or "Acid" type floor textures.
There are three classes of damage, -2/-5%, -5/-10% and -10/-20%. The first number is the amount of damage on skill 1, the second number is used on all other skill levels.
Secret Rooms:
To make a sector count towards the SECRET ratio given at the end of the level, set the secret sector special. The player will receive credit for the discovery of the secret if he has stood in the sector. You should place this in sectors behind secret doors, or in hard to get to sectors. Secrets are usually associated with "extras" - that is, places that the player does not have to go in order to complete the level.
Other Effects:
There are a number of other special effects available though the use of the sector special attribute. Consult [UDS:4-9-1] for details.
