### THE ADD SPECIAL BUTTON

The Indian Fakir a.k.a "Machismo"

www.unrealism.com/unrealedmax

cool_machismo@yahoo.com

### INTRODUCTION

This tutorial will put the add special button through the paces. It will deal with all the uses that this button can be put through.

When you hit the add special button the dialog on the left opens showing the various properties that you can assign to the surfaces of the brushes that you create and the one on the right shows the pull down menu where you have some pre-configured types that you just have to choose and add in. Lets discuss the setup and use of these pre-configured ones first. This tutorial is meant for those of you who are starting out in UnrealEd2 as some parts are really basic (BUT people who are in other levels may find the Semi-Solid Brush State part useful).
TIP: The sheet builder which builds a sheet should only be used along with the add special button. This means that if you want to build something using the sheet use only the add special button and not the normal add button that you use for cubes, etc.

Tutorial Subsections - This tutorial is divided into the following subsections. Just choose any one of these topics to jump there.

1. Water

2. Semi-Solid Brush State (IMPORTANT)

3. Zone Portal

4. Transparent Window

5. Masked Decorations

6. Invisible Collision Hull

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### 1. Transparent Window

Lets build a quick tutorial map and see how to make windows for your level. Build a cube 256x256x768 and subtract it from the null space in a new level. Next build a cube 256x256x32 and add it into the center of the room. Next build a cube 128x128x32 and subtract it from the center of the room - this is where you will place the window. Load the GenIn.utx or Coret_FX texture package which has got some nice glass textures.
TIP: To see only the glass textures for a certain texture package choose glass in the pull down menu below the loaded texture package (see picture to the left).
Build a sheet u=128 and v=128 with x or y orientation. In this case since we know the exact measurements of the hole for the window to go into so we can just add it using the same size. If you have a hole for a window to go into and don't know the size just build a sheet slightly larger than the hole and then add in the window. Now that the sheet is built just choose a nice glass texture (I used the SpecGlass texture from Coret_Fx). Hit the add special button and in the drop down menu just choose Transparent Window, leave the other settings alone and hit the add special button. If you did everything correctly up to now you should get a nice window in your level now.

### 2. Masked Decorations

Interesting and fun things to give that "special" look to your level. For now load the GenFX.utx texture package and just like we did for glass choose mask from the drop down menu below the texture. Build a sheet and place it where you want it to go and hit the add special button. Just choose masked decoration from the drop down menu and hit add special. For this example you can leave the visibility at 1-sided, but for example you may want vines hanging from the center of the room to be seen from both sides, then check 2-sided. You can make some fantastic looking stuff, everything in the following picture was done in the same way:

NOTE: The arch was created with the 2d Editor, after you become more familiar with the editor you may want to head down to the advanced tutorials section and read my 2d Shapes tutorial.

### 3. Invisible Collision Hulls

If you have played your level you would have noticed that you will be able to walk through the window and the masked decorations. Never heard of a person being able to walk through glass so the best way to stop players would be to set up a collision hull. What this does is place an invisible barrier that the player cannot see but yet blocks the player from passing. Just build your sheet or brush and place it in front of the glass that you wan the player to be blocked from entering and choose invisible collision hull and hit add special. In the picture above I added in a collision hull only in front the arch grate, the other decorations like the straw and vines need not have a collision hull as the player can pass through them in real life, why not in unreality.

TIP: If you are an observant person you would have noticed by now that the various types of brushes that can be added in are just a variation of the regular brush. This is in the sense that you can create everything by changing the combination of settings for the regular brush to get different types like the collision hull.

TIP2: All the different types of brushes that you can add into the world with this button will be shown by different colors in the 2d views. For example a masked decoration will be a light green brush in the 2d view, a collision hull brown and so on.

###

### 4. Zone Portal

Use this to divide the level into separate zones so that they run faster. For more information you can read the Miscellaneous Zone Classes tutorial here. Note that its best to place the zone portal in narrow hallways and such. As any advanced mapper will tell you making very large zone portal brushes can cause your level to slow down instead of speeding it up - which is the main purpose of zone portals in the first place.

### 5. Water

The water subclass is a prefab that helps you to build a water sheet to convert an area into water. Lets take a very simple example to see how to make water. Here's a simple five steps to making water:

1. First make the room in which you want to put the water in - say about 1024x1024x1024.

2. Next make the brush to hold the water -say about 256x256x1024 and place it to the side of the room, align it in the side view so that it touches the bottom of the first room and subtract it so that you get something like the following :-

3. Next lets make the water. Since we know the size of the brush into which we will put the water lets build a sheet 256x1024 - this will be the size of the water brush. Load the genfliud.utx texture package this has all the base water textures now just select one water texture that you like. Now make sure that the sheet is a little lower than the subtracted brush that should hold the water. All you need to do now is hit the add special button and choose water and hit OK to close the dialog. The final level should look like this:-
   Notice that the water is a little lower than the brush that holds its.

4. Now this is not enough. You will notice in the add special dialog that the water brush is nothing more than a transparent, non-solid zone portal brush. You just need to place a Water Zone actor below the water brush so that it tells the editor that this is a water zone. (You'll find the water zone actor from under info|zone info.

5. Now just place a player start and some lights rebuild and play the level. You should be able to hear the sounds when entering and exiting the water and if you stay too long underwater you should start losing health. That's all there is to making water.

TIP: If you make the brush to hold the water using the 2D editor so that it is in an irregular shape there are two ways of making the water sheet. (If you haven't read it as yet please read the 2D Editor Tutorial its very important).
For irregular shapes outside it will be easier to build the water brush using the sheet tool. But imagine if you have a tank made using the 2deditor then it would be better to build the water brush using the 2d editor.

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### 6. The Semi-Solid Brush

The semi-solid brush state is a very important one (the other two are solid and non-solid ............. duh!). A semi-solid brush is one that does not cut up BSP and yet blocks the player. The solid brush cuts up BSP and blocks the player whereas the non-solid does not cut up the BSP or block the player either. The semi-solid brush appears as a brown colored brush in the 2d views. The easiest way of verifying whether whether a brush is a solid or a semi-solid is by "flying" through it in the 3d view. Say you have a pillar brush that touches the floor and ceiling of a room. If it were a solid pillar and you flew into the middle of it in the 3d view, you would literally be able to look into the void outside the room/level. But if it were a semi-solid pillar and you flew into the middle of it you would only be able to see the pillar touching the floor and ceiling - you would not be able to see into the void.

IMPORTANT: Adding in a semi-solid brush is as easy as as making the brush via primitives or the 2d editor, placing it in the level where you want it, hitting the add special button and then just choosing semi-solid pillar from the pull down menu and hitting Ok.
UnrealEd2 allows you to change the state of solidity of a brush on the fly. This means that if added in a brush and later need to change its solidity to a different type you can do so. Just select the brush in any of the 2d views - or hold down shift and left click on one of the surfaces of the brush whose solidity you want to change. Now right click and in the menu that appears just scroll down the list until you reach solidity and select semi-solid, like this:
This naturally works vice-versa as well.

The semi-solid helps to drastically reduce the node count of a level (the amount of nodes or vertices that a player can see at any given time). And if the node count is reduced the level will run faster. Take for example a level that I was making - it had a total of 842 brushes - 146 subtracted, 123 adds, 518 semi-solids and 54 non-solid brushes. At this point the node count for the level was 9805:
You can get the full statistics for your level by doing a complete rebuild of it - don't forget to turn on BSP under the options tab of the rebuilder. Now I selected all the semi-solid brushes in the level and converted them to solids. Now I did a complete rebuild of the level and the Node Count jumped to 12000. Not only did this considerably turn up the node count it slowed the level down drastically - besides creating a few horrible Hall Of Mirror (HOM) effects!.

This may make the semi-solid brush seem like a dream but building the entire level out of semi-solid brushes is a terrible idea as there will be many problems with your level. You need to find a balance between excessive use of semi-solids and not at all. Some times it can be a trial and error method. The semi-solids have several problems. For example since it does not cut up BSP you cannot add a semi-solid brush to your level and then subtract from within it - you can only do it to solid brushes. Sometimes use of the semi-solid brush itself can cause the HOM effect where due to a compile error you are able to see into the void or you will be unable to move within that part. So you need to be very careful with the placement of semi-solid brushes.

Semi-solids are great for creating complex decorations that have been intersected. For example I created a chimney out of 10 brushes - 5 added brushes and 5 subtracted brushes, like this:
Notice that there are 49 nodes being drawn in this picture and that the amount of polys is 22. Now I just moved these brushes outside the level into another box and intersected them and placed the brush in the same place as before but I added it in as a semi-solid brush. Look what happened to the picture:
The node count got reduced from 49 to 32 - this may seem like a very negligible amount but if you carried out this practice in your whole level you may be able to reduce your node count by at least 1000. Its better to keep the whole total node count of your level below 10000. And this is where it can matter a lot - just a few nodes may make the difference in your level speeding it up just that extra bit.

But then again intersection is not all that it is cracked up to be. In the above case it proved to be very helpful. But it will not always be like that - intersection in some cases will actually increase the node count. Take a look below:
Some people would have considered the semi-solid brush an ideal candidate for deintersection. But if I had deintersected the original builder brush I would actually have added more vertices to the level thereby increasing the node count. That is why I have left the brush as it is jutting out with an extra bit. Again this is something you will have to decide based on the situation - you'll know when to do it as you get more experienced. But generally speaking it is better not to intersect/deintersect against irregular brushes as this will definitely add more vertices to your brush.

The semi-solid is great for decorations as I mentioned before (especially for that ubiquitous and clichéd crates that every level designer uses ;). Well learn to use the semi-solid wisely as it is great answer to many problems that you may face - especially slow levels. This part of the tutorial has been too much like a sermon and I better end it before it gets too preachy ;).