Lode's Exploding Wall & Breaking Glass Tutorial v1.1

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Table of contents


You'll need basic editor knowledge and a good knowledge of movers for this tutorial, I suggest you read Lode's All about Movers Tutorial.


There are a lot of tutorials on breaking glass or exploding walls, but not one of them explains all the properties of the ExplodingWall or BreakingGlass classes.  This one does.

The EplodingWall Actor

Open the Actor Class Browser, expand Effects and locate ExplodingWall.

The ExplodingWall Actor

This actor can create fragments, pieces and splinters of walls, glass or wood.  You can choose size, texture, sound and other variables for 3 different kinds of fragments.

It creates the effect whenever it's triggered by a trigger, a mover, or any other event.  In most cases, you use this in combination with a mover: the mover is the wall that will break, and when the effect happens, the wall mover goes to another keypoint, so it'll look like the wall disappeared.

But it is not the mover that creates the explosion effect, but the ExplodingWall actor does.  So if you place the ExplodingWall actor 10 meters away from the mover, it will look like a wall disappearing, and 10 meters further some fragments that appear out of nothing.  When you place the ExplodingWall actor inside the mover, this creates the effect as if the mover explodes.

The ExplodingWall also has the BreakingGlass extension, used for breaking windows.

A basic Exploding Wall

First make a wall.  Then make a brush that looks like a hole that was shot out of a wall.  Best is to use the 2D Shape editor and use Extrude.  Make the hole as thick as the wall.  Make sure the red brush is transformed permanently.  Place the brush on the wall.  Now press in this order: Intersect , Substract , and Add Mover Brush .  You just made the hole in the wall and added a mover in it, so the hole will be filled until the mover goes away.  There should be a yellow, a purple and a red brush on the same place.

Create a hole in the wall and fill it with a mover

Place Key1 of the mover somewhere outside the map, then select Key0 again so the mover is back inside the hole.

Set Key1 of the mover to somewhere outside the map

Oped the Properties of the mover and change the following settings:

Add an ExplodingWall inside the mover, open its properties and change these settings under ExplodingWall:

Place the ExplodingWall inside the mover for the most realistic effect.  When you used the correct Event and Tag, you should see a red line going from the mover to the ExplodingWall.

Place the ExplodingWall inside the mover

When you now open the map and shoot the wall, it might look like this:

The fragments fallen on the ground after shooting the wall

If you have bOnlyTriggerAble = True and you find out that you can not activate the mover if you shoot in the middle of it, then the ExplodingWall is in the way and blocks your shot!  The solution is to set all the Collision to False in the Collision settings of the ExplodingWall.

All ExplodingWall Properties

In the previous section, you only used a few settings necessary in that particular situation.  Here's a list of all the proporties and an explenation.  As you can see, there are 3 differend kinds of particles that can be casted, all at the same time.  For every kind of particle you can choose a size and a texture.  If you have a brick wall with a window in it and also some wood, you can use them all at the same time.

bOnlyTriggerable If this is False, the explosion will be able to be started by two things: If the BreakingGlass actor is triggered by an event called by a trigger, a mover or whatever, OR if you shoot at the BreakingGlass actor with any weapon.  If this setting is set to True, it can only be triggered by the event, and not by the weapon.  This does not work with the normal ExplodingWall actor.
EffectSound1 These don't seem to work
ActivatedBy This is explained in the section "ActivatedBy"
BreakingSound The sound that will be played when the explosion starts
bTranslucentGlass If True, the GlassChunks will be translucent
bUnlitGlass If True, the GlassChunks will be unlit
ExplosionDimensions This is how the radius of the explosion itself: all the particles will start somewhere inside this radius.  This is the radius of a sphere around the ExplodingWall actor.
ExplosionSize This is how fast the particles will fly and thus how far they'll fly away from the origin.
GlassParticleSize The size of the Glass Particles.  1 is normal, 10 is really large
GlassTexture The texture of the Glass Particles;  set this to the same texture as the glass or window that breaks
Health This is explained in the section "ActivatedBy"
NumGlassChunks The number of Glass, Wall or Wood Particles that will appear.  Note that in reality the number of them will not always be the same, and most of the time much less.
WallParticleSize The size of the Wall Particles
WallTexture Set this the texture of the wall that explodes, to make it most realistic
WoodParticleSize The size of the Wood Particles
WoodTexture Set this the texture of the wall that explodes, to make it most realistic.  If you set no texture, a default wood texture will be used


Thanks to 32_Pistoleta who figured this out and sent this list!

In ActivatedBy, you can fill in names of DamageTypes.  If you fill another name than exploded in here, the ExplodingWall will ONLY be activated by the DamageType you entered.  The DamageTypes are caused by specific weapons, here's the list of all the weapons responsible for every kind of DamageType:

Make sure  bOnlyTriggerable is False and the mover does NOT have an Event, otherwise you can still activate it with any weapon if you shoot the mover!  Instead, give the ExplodingWall the Event to activate the mover, and set the InitialState of the mover to TriggerOpenTimed.

So, if you want your wall to explode only by the shockrifle, just input the string 'jolted' in ActivatedBy.

With the Health setting you can give the ExplodingWall a certain health, so you need several shots before it Explodes.  The list of what weapon gives what damage is in the section "A Basic Exploding Wall".

Breaking Glass

The BreakingGlass actor is an extension to the ExplodingWall, and has a few more options, in BreakingGlass: Numparticles and ParticleSize.

These 2 options replace the NumGlassChunks and GlassParticleSize settings of the ExplodingWall.  You can make a breaking glass effect with the ExplodingWall as well, but the BreakingGlass has some settings already prepared for you, for example the sound and explosionsize.

For the sound, texture, unlit and translucenty settings, you have to use the same properties as the ExplodingWall.

To make the window, first make the gap in the wall, and then use a mover that is one unit thick, with translucent surfaces.  You can of course use a sheet, but sheets don't block players unless you use an invisible collision hull, which means you have got to use two brushes instead of one.  Apply the same properties to the mover as for the exploding wall explained in the beginning of this tutorial.

When you have this and rebuild, you see that the light does not go through the window.  To make the light go through the window, open the properties of the mover, expand Mover and set WorldRayTraceKey to 1.  Now the light will be calculated as if the brush of the window is at its second key, outside the map, and the light will go through it!

Add the BreakingGlass actor, give it the correct Tag, and apply all other necessary properties like the ExplodingWall in the beginning of the tutorial.  It's best to set bUnlitGlass and bTranslucentGlass to True, for the best effect.

Respawning Walls and Windows

In multiplayer maps, you may want to have these exploding walls or windows to respawn so other players will be able to shoot it again.  To do this, change the following properties:

In the properties BreakingGlass or ExplodingWall actor, in "Advanced":
-Set bNoDelete to True.  That way the actor will not be destroyed after it has done its job, and can do it everytime again if it's triggered.
-bOnlyTriggerable = True.  Otherwise players will be able to activate the effect over and over by just shooting on it, even if the wall or windowmover is away.

In the properties of the mover, under "Mover":
-bTriggerOnlyOnce = False
-Set StayOpenTime to the time you want the wall or window wait before it "respawns"



The Future

I WILL update this tutorial

If you have any ideas, problems, suggestions, questions or have discovered a mistake, don't hesitate to contact me!  Thanks a lot.


my email adress is at: https://lodev.org/contact.html

Copyright 2000-2001, Lode Vandevenne

Please do not upload this tutorial to any site, only make a link to https://lodev.org/unrealed/  .  Otherwise older versions keep hanging around on the net.