Special Effects
UnrealED2 Tutorials by EZkeel

Multi SkyBoxes

Email :EZkeel
Accompanied files : MultiSkies.UNR

Tutorials you will need to have read are: Skyboxes, Movers (hmm, that gives the game away!)
If you’ve looked into some of the levels that came with the original Unreal, you’ll probably notice that some of them actually have two skyboxes. This gives the mistaken impression that you will actually see two different skies during the course of the level which isn’t the case. The skyboxes you see in the editor are created so that one will work on PC’s set up for high graphic performance and the other for low graphic performance.

It is possible to have more that one type of sky in Unreal/UT, but as with so many other special effects you’ll have to do it through illusion! It involves creating a basic skybox area in which there are lights toggled on and off and two sets of moving brushes that switch between each other, rather like a theatre switching scenery when the curtains are down!

1) Create a basic room with all your walls and ceiling set up as “fakebackdrop” as you would normally. Put a player start in there, light it and set the game info to singleplayer.

2) Now create a skybox in the usual way but use trigger lights instead of ordinary lights. Get it looking exactly how you'd like it and then delete the skyzone info actor (if you'd put one in there).

3) Now create a second skybox completely different to the first and again using trigger lights rather than ordinary lights. Do the same as last time and delete the skyzone info actor.

4) Neither of these will be your real skybox, instead they will be the blueprints for two movers that will act as the brushes for your skies. For your real skybox, create a large cube which is much bigger than either of your first two skyboxes.

5) Make your builder brush slightly larger than the first skybox you created and intersect the whole thing. Now position the brush inside the large cube you created in step 4 and create a “mover” brush with it. Do the same for the other skybox too and ensure that both movers have their central point are in roughly the same position.

8) Take your first “skymover” and call it "sky1" in its tag field. Also make sure bdynamiclightmover is set to true. It should also be set to trigger toggle and have a move time of 0.

9) Move it outside the cube (the start position). Now select keyframe 1 and position it back where it was a moment ago inside the large cube in your “real” skybox area (end position). Now reset it to keyframe 0.

10) Repeat steps 8 and 9 for the second "skymover" but call this one "sky2" in its tag field.

11) Now place a skyzoneinfo actor in the large cube. You'll probably need to place both "skymovers" to position 1 temporarily to make sure you put the skyzoneinfo actor in the right place.

12) Now for the lights - here's where you find out why you had to use trigger lights ....
Select all the triggerlights inside the first of your original sky boxes and drag them to the corresponding position inside the large cube. Set them to "trigger toggle" in their initial state, give them all a tag name of "lights1" and set the "initially on" field to false. It will also be helpful for you later if you give them a group name of "lights1" too in case you want to change them all later.

13) Do exactly the same thing with the trigger lights from the second skybox you made in step 3 but give these a tag name of "lights2" and also the group name of "lights2". You should now have two sets of lights within your new skybox ready to switch on and off at your leisure! (Remember to set your skymovers back to keyframe 0)

14) All that's left for you to do now is trigger them off. Make sure at least one of these skyboxes is triggered at the start of your level. You can use an ordinary trigger to set off a dispatcher that triggers "lights1" and "sky1". When you want the player to see a new sky, simply trigger "lights2" and "sky2" in the same way. Remember though that if you trigger one of them on, you must trigger the previous one off if it was showing up.

Of course, there is one disadvantage with this method. Only one of the skyboxes can be viewed at any one time so you'll have to be selective how you use this.