NaturalTvventy's BOOM Tutorials 01: Using BOOM's light glow/fade

[NaturalTvventy]

I love working in BOOM format and exploring it's lesser-used features. I thought I'd start writing tutorials for the format as I learn new things about it.

 

The Boom Edit Example Wad has a room whose light level brightens and fades as a door opens and closes.

 

 

I want to create a map where a player hits a switch to slowly reveal a large light source, smoothly upping the light level of the area in the process. The BOOM light glow/fade feature seemed like the best tool for the job. Of course, it's not as easy as it could be. 

 

Here's what I discovered:

 

• The effect is not achieved by the standard linedef special/linedef tag -> sector tag. Instead, the effect is achieved by making use of D* (door) linedef types.
• The effect cannot be created with S*, G*, W* (switch, gun, walk).
• The effect is produced by tagging a D* linedef with a door action and a linedef tag. Any sector with the same tag will have its light level affected.
• The effect doesn't work with raising ceilings. It must be a door action.
• The rate of glow/fade is dependent on the time the door takes to open or close. The longer a door takes to open, the slower the glow will be.
• Tagged sectors will fade up to its brightest neighbor. An exception I found is if two neighboring sectors have the effect applied to it. Any neighboring sectors will glow to the level of the brightest neighbor of all the sectors. This makes it somewhat tricky to have fading occur to different levels in neighboring sectors. The solution is to use the transfer floor brightness and transfer ceiling brightness BOOM specials. This will allow small sectors between fading sectors which are hidden by the transfer light level special.

 

The effect being tied to D* linedefs make it tricky to work with. W* and S* can't be used directly. However, monsters can activate D* linedef types if it's the original DOOM DR open/wait/close or, even better, with standardized linedef actions. I think that to use this effect more robustly it's best to create monster closets. Create a closet with a monster which can't reach a door due to a high floor. Make a switch or a walk-over action which lowers the floor and allows the monster to reach the door. The monster will then open the door and trigger the effect. You'll of course want to teleport the monster into your map after unless you are cruel and want to make 100% impossible.

 

Here's the wad I made where I played around with the effect to get it work. In the map the player hits a switch which grants a pinky access to a generalized door. When the pinky opens the door the room glows brighter. I've shown how to get the effect to work differently on what appear to be neighboring sectors. these sectors actually have a sector between them with transfer floor/ceiling brightness specials applied to them.

Edited December 14, 2019 by NaturalTvventy

[Gez]

49 minutes ago, NaturalTvventy said:

The monster will then open the door and trigger the effect. You'll of course want to teleport the monster into your map after unless you are cruel and want to make 100% impossible.

You can make a dehacked monster that has like only one frame of animation (with A_Chase on it so it can decide to open doors), and does not have the COUNTKILL flag. Sacrifice something like the redundant marine corpse, give it the sprite of the gray stalagmite, there you go. You need BEX to put a codepointer to a state that doesn't normally have them, but it's fine since it's for a Boom feature anyway.

[Graf Zahl]

You need at least two states for that - one with A_Look and another with A_Chase.

But you can do it without sacrificing any states. Just give that dummy actor the see and spawn state of the zombie, and leave the rest empty. As long as it cannot be seen, who cares how it looks?

 

[NaturalTvventy]

Since it's an opening door which triggers the effect you can have fun with it. You can release new enemies into your map through the doors while also brightening an area.

[RonnieJamesDiner]

Nothing brightens my day like a monster closet. Heuheuheu… sorry, I had to do it. This is really cool though, thanks for sharing! I'm always happy to find new sources of BOOM tutorials and techniques, it's a format I know very little about.

[xvertigox]

I feel like you could create some cool effects with this using a teleport trap setup where walking over a linedef opens the first door and then the monsters in the trap open a secondary (very tall) door with a D1 Open Stay action. Could make for a cool effect outdoors or something?

 

This reinforces the fact that I should start Boom/MBF mapping rather than just limit-removing.

 

Edit: Just saw that @NaturalTvventy posted basically the same idea - good stuff.