*Note: I created the most of the tutorials using the Roboblitz and Gears of War editors. Based on the engine, and the version, some properties specified may be in slightly different locations than what is displayed in the screenshots.

If you need to learn how to create a basic map I would reccomend:
For UT99, UT2K3 & UT2K4: the Unreal Wiki.
For UT3: Waylon's Tutorials.



Common Interactives - Raising/Lowering Liquids

I have set up a simple test map consisting of a few slabs of BSP, a skylight, a playerstart, a skydome, and a directional light.

I will primarily be using default editor assets which can be found in the EditorMeshes and EditorMaterials packages. For this example, I also grabbed a flat sheet static mesh, and a water-like material.

After much experimentation and back-and-forth with SkullKrusher101, we've discovered that the most ideal way to work with rising/falling water, or other liquids, is not workable. We found that very few volumes have a 'Movement' property inside them which is the key to making much of anything move in the editor. So after experiemnting with different techiniques, different volumes, and some Kismet variations, our conclusion is that there's no easy way to do it.

And so, until someone comes up with a better way, we have determined that the only current method for rising/falling water/liquid is the following:

*Note: It is assumed that you are already familiar with creating water in the editor. Remember - water is a combination of two pieces: a volume (which handles the physics, particles, and sounds) and a surface - usually a static mesh - which makes the water look like water when viewed from above (and, ideally, below). The shape of the liquid is defined by it's surface mesh, it's volume shape, and/or its physical boundaries (BSP, other meshes, and/or terrain).

Let's use the 'Cooking' analogy I outlined in the Applications Introduction to set this up:

1) What are we making?
A pool that the player can raise and lower using "use' Switches.

2) Gather the ingredients:
2 Triggers
2 Interpactors (water sheets)
2 Matinees
2 Trigger 'Used' Events
2 Toggle Actions

3) Put it together.
In the level, I have set up some BSP to be a small boxy pool. I am going to set up the system to 'turn on' the water when I hit a switch at the bottom of the 'pool' and then the water will rise, and I'll be able to climb out again. Once the water is up, I'll be able to use the switch at the top to 'drain' it again.




On the Kismet side of things, I'm just going to deal with the basic mover setup first. I'm using two interpactor sheets because the material I chose was one-sided, as is the mesh. So I took one, flipped it upside down, and placed it just slightly below the first one. This way, we'll get a water surface looking down at the water, but also looking up at it from below.

First, I set off the trigger Used Events to play a raising matinee for the lower trigger, and a lowering matinee for the upper trigger. In the matinee, I used two movement groups - one for each water plane - and set their movement tracks to 'World Frame'. Then, I used each 'Completed' of the matinees to turn on the appropriate trigger. The matinees have both been set to 'RewindonPlay'. The trigger events are each set to turn themselves off as soon as they're activated using toggles. The trigger event that will lower the water is set to 'off' by default using it's bEnabled property.




Now we need to work in the Dynamic Water Volumes. So we're going to repeat step 2 with extra ingrediants:

2) Gather the ingredients:
4 Dynamic Water Volumes
9 Toggles
8 Delays
1 ObjectList Variable

3) Put it together.
For this, we'll create a series of Dynamic Water Volumes that are all turned off by default, and then we'll turn them 'on' incrementally. The water volumes are not going to move. They overlap each other and gradually ascend the pool in height as shown. You'll probably want to tweak the distances and timing between them so that a player in it ascends it reasonably.




So, basically what we're going to do is turn them on incrementally with slight delays between them. My overall matinee time is 5 seconds, so I'm going to turn them on at 1 second increments. If needed, you could assign events to the matinee in a matinee track and turn them on by using the matinee events. I'm also going to add a toggle turning them all off initially since the water will be 'drained' when the system begins. I'll use a Level Startup Event to do this. I'll use an ObjectList to hold all the volumes inside one reference to turn them off.




Here's the exact same setup excapt this time I've used matinee events spaced out at 1 second intervals in Matinee:




4) Test it. Go in game and test it out. It worked fine for me.

5) Refine it. First, think about the collison and lighting and get those fixed. Then consider any potential issues. Well, we have toggles shutting of the appropriate triggers at the appropriate times and I really haven't been able to think of anything else so...

One extra thing I have done to 'enhance' the underwater effect is I've overlapped the Dynamic Water Voumes with PostProcess Volumes and added them to the system as well. The post process basically makes it look more 'underwatery'. Here are two screenshots with the delays and without that include the new volumes.




Here's the exact same setup except this time I've used matinee events spaced out at 1 second intervals in Matinee:




6) Adjust it for Single/Multiplayer. As you may have read in the SinglePlayer/Co-op/MultiPlayer section, there are many considerations to take into account for whichever system you're setting this up for. The system as it stands I think would be ok for single-player and multiplayer both. But if you make any serious changes to it, you should still ask yourself some questions. What happens if two players are fighting on, around, or in it? Actually, it looks like that might be ok.

Other Liquids: Changing it to be a Slime, Lava, Toxic Waste, Juice or other liquids.

Although there are Lava and Slime Volume types, there aren't any Dynamic versions. However, converting a water volume to a lava or slime volume is very simple. Create a Lava volume (or slime) and lock the property box (the lock is in the upper left of the properties window). Then, create a Dynamic Water Volume. Now, expand down the properties of the lava volume and dynamic water volume and change the properties in the dynamic water volume to match those of the lava volume. When you're done, they'll function identically. Of course, you'll also want to choose a new material for your water surface so that it will look like lava/slime/whatever.