Foreword: This tutorial assumes you have both Half-Life AND at least Worldcraft v2.0 (it is suggested that you get Worldcraft v2.1 from the Files page). This tutorial is designed for those of you who have a good ammount of experience with Level editing and CSG (Constructive Solid Geometry) or Brush-type maps. This tutorial assumes you have completed the previous tutorials in this series.

This tutorial covers: - The func_tank entity - The func_tankcontrols entity - The ambient_generic entity (briefly)

    Greetings, and welcome to the func_tank tutorial. You could probably imagine that I get many questions concerning creating controllable turrets. Hopefuly this tutorial will answer all of those questions. Func_tank, I must admit, is pretty easy to use, although it is a little confusing at first glance. However, by the time you complete this tutorial you will be able to make controllable turrets with the greatest of ease. To get the most out of this tutorial, I suggest going along with me in the construction of our very own turret. Make note that every action I want you to perform is colored blue.  

    Our first step of course is to open Worldcraft. Make sure that you have the latest .FGD entity file from either http://halflife.gamedesign.net, or right here in the Wavelength Levels Dept. Also make sure that you have Worldcraft 2.1... although turrets work with WC 2.0, it's always best to have the most recent version of programs that you are using. Alright, now that everything is in order, create a new map file. The first thing that you have to do when making a turret is to actually create the whole turret out of brushes first. I suggest that your grid size in Worldcraft is set to 8. If you'd like to see how I have WC set up, click here. You may notice I don't have the VISGroups box in view; I like to keep it deactivated unless I need it so it doesn't clutter up my workspace.  

   Well, now the actual construction of the turret itself is done, but there's still some stuff to add. From now on, I'm going to refer to the different parts of the turret by name... the bottom will be the base, the center will be the stand, the top large block will be the body, and the long block extending from the body will be, of course, the barrel. Every turret needs an origin brush. In case you don't know, an origin brush acts as the center location for any rotating entity. It tells Half-Life what point the entity is rotating around. That means that our func_tank is gonna need an origin brush since it's going to rotate around. An origin brush is just a normal block with the 'origin' texture covering every side, much like a clip brush. Remember that the CENTER of the the origin brush sets the point where the turret will rotate. Open the texture browser and type 'origin' in the filter. Double-click on any 'origin' texture that shows up. Now, make a new brush in the top view, anywhere you want. Size it so that it is 32x32. In the front view, resize it so that it is 48 units tall. Now you can push enter to create the block. Now comes the hard part; placing it in the right location. You're going to have to move it so that the X that represents the center of the origin brush is right where the turret body and stand meet. Make sure this is the case for each view. Zooming in can help alot...

Take a gander at this image to see how it should look.

The 2D views, as you can see, are zoomed in, and the origin brush is selected so it stands out. Now, why did we place the origin where we did? Well, since we are going to want only the turret body and barrel to move, I put it so it's center was at the location where a turret would normally rotate; right where the body and stand meet.

   Hopefully you're still with me so far, but don't fret... now we get to the fun part; actually making the entities! Alright, now select the body, the barrel, and the origin brush. Remember, to select more than one object hold down CTRL and click on each of the objects once in the 3D view. Good, now click the toEntity button. (Make sure ONLY the body, the barrel, and the origin brush are selected.) From the list of entities that pops up, choose 'func_tank'. This brings me to an important rule that you MUST follow if your turret is to function properly... always build your turret facing RIGHT in the top view, and then adjust the direction it will be facing when the game starts by setting the direction with the 'compass' tool (angle key) in the turret's properties. Since this is just an example turret, we can leave the compass heading at 0. Now, I'll help walk you through each of the keys we'll have to set up:

• Name: We'll have to give the turret a name, so right now put 'turret' for the Name key.
• Target: Let me make something clear to you. The turret doesn't automatically make gunfire noise when it shoots. But, everytime it does fire, it triggers whatever is inside the 'target' Key. So, to make a gunfire sound, we'll put the name of an ambient_generic in the turret's 'target' field. As you know, we haven't actually made the ambient generic entity yet, but we can still put a name in that we will use for the ambient_generic later. Let's just put 'gunsound' in the 'target' field.
• Render Settings: We don't have to worry about the render settings, so leave Render Mode, Render FX, FX amount, and FX color alone. Also ignore 'global entity name'.
• Yaw Rate: That brings us to Yaw Rate. Yaw Rate controls how quickly the turret turns left and right when the player aims with it. For a large mortar turret, you'll want something low like 200, but for a turret this size, an ammount around 550 will be nice. Enter 550 into the Yaw Rate key.
• Yaw Range: Yaw Range controls the range in which the turret can move left and right in degrees. However, this key ONLY applies to monster-controlled turrets, so leave as is.
• Taw Tolerance: Yaw Tolerance only effects the turret if it is monster-controlled, so we don't have to mess with it. I'll be dealing with monster-controlled func_tanks in the next tutorial.
• Pitch Rate: Pitch Rate is the same as Yaw Rate, but Pitch Rate controls how fast the turret rotates up and down. Enter 550 in this one also.
• Pitch Range: Pitch Range is also like Yaw Range, but it controls how far the turret can move up and down in degrees... it also only deals with monster controlled turrets, so leave it alone as well.
• Pitch Tolerance: Pitch Tolerance is just like Yaw Tolerance, except for up and down, so just ignore it.
• Barrel Length: Barrel Length is the distance in units from the center of the origin brush to the very tip of the barrel. I measured 96, so enter 96 in the Barrel Length key.
• Barrel Horizontal: Barrel Horizontal acts as a horizontal offset... if the turret barrel is to the left or right of the center of the origin brush, you enter how far over it is here. A positive number is to the right, and negative is to the left. Since our barrel is perfectly aligned with the origin brush, enter 0 in the Barell Horizontal key.
• Barrel Vertical: Barrel Vertical measures the distance from the center of the origin brush to the center of the barrel... I measured 12 units, so enter 12 in the Barrel Vertical key.
• Smoke Sprite:Smoke Sprite is the file name of a smoke sprite file from the pak0.pak file in your Valve directory that will act as the smoke from the end of the barrel. I recommend leaving this blank, since in my experience smoke sprites have always gotten in the way. So make sure Smoke Sprite is blank.
• Flash Sprite: Flash Sprite is the name of the sprite image file from the .pak file that will act as the flash of fire from the barrel of the gun whenever you fire... this is a cool thing to have. The format for the sprite file location for this key is directory/filename.spr. For our turret, we'll want to use sprites/muzzleflash2.spr.
• Sprite Scale: Sprite Scale lets you adjust how large the flash and smoke sprites are... we can just leave this key at 1.
• Rotate Sound: Rotate Sound is the sound to play when the turret moves, or rotates... this won't be very good since our turret is so small, so go ahead and leave Rotate Sound blank. I recommend that you pretty much always leave a Rotate Sound out, it just gets annoying after you use the turret for awhile. But then again, that's just my opinion, the decision's up to you.
• Rate of Fire: Rate of Fire is the rate of fire per second. Since we have a small, machine gun-like turret, we'll want this to be something like 15. So enter 15 in the Rate of Fire key.
• Damage per Bullet: Damage per Bullet is the ammount of damage a player will recieve for each bullet that hits him/her. Since this is a rapid-fire turret, the damage level should be low... like around 4. So enter 4 in the Damage per Bullet key.
• Firing Persistence: You can ignore Firing Persistence, it only effects the turret if it is controlled by a monster.
• Bullet Accuracy: Bullet Accuracy, of course, is how accurate each bullet is. Since we have a rapid-fire turret, the bullets aren't going to be as accurate, so select 'Medium cone' from the list.
• Monster controlled turret settings: Minimum target range, maximum target range, and minimum light level all only deal with monster-controlled turrets, so ignore them.
• Bullet Type: Last (but not least) select the type of bullets you want our turret to fire. I selected '9mm'.

    We are very close to finishing now! Two things remain to be completed; we have to add our ambient_generic entity, and put in our func_tankcontrols. Right now, click on the Worldcraft entity tool (the lightbulb). From the entity list choose 'ambient_generic'. Click once anywhere in the top view to place that entity in the level. Remember that you still have to press enter to create it, so do that now. Make sure the ambient_generic entity is selected, and move it so that it is directly over the center of the turret body. In the front view, make sure it is about 32 units above the center of the turret body.

Click here to see exactly where to place the ambient_generic.

Note that the small purple box is the entity. In case you don't know, all ambient_generic does is play whatever sound you specify. Right click on the ambient_generic entity, and select 'Properties'. Since this tutorial isn't about ambient_generic, I'm just going to quickly walk you through what to enter for the keys:

• Name:Remember what we put under the 'Target' key for our func_tank? That's right, 'gunsound'. So, under the 'Name' key, enter gunsound.
• Path/filename.wav of WAV: For 'Path/filename.wav of WAV' enter ambience/biggun1.wav. Put 10 for the Volume key, since guns are loud :-)

    Excellent, we now have our gunfire sound that will play when the turret is fired. Now, you might be wondering how you can tell Half-Life where the player has to be standing to control the turret (by pushing the USE key). This is controlled through the func_tankcontrols entity. This is a pretty simple enity to use. It works just like any other func_* trigger; you must attach it to a solid. In this case, imagine that the func_tankcontrolls has a control panel on each side. The player can't be standing inside a control panel, but he can use it by standing right next to it and manipulating it. This is how func_tankcontrols works. Instead of actually defining an area where the player must stand, it defines an invisible panel that has the controls for the turret on it. Before starting on the block, open the texture viewer, and type 'trigger' in the filter. Double-click on any trigger texture that shows up. Anywhere in the top view, make a new block that measures 8x96. In the front view, adjust it so that it measures 112 units tall. Now, move our new block so that it is aligned right next to the base of the turret in the top view, and so that it is on the same level vertically with the base in the side view. Now press enter.

Click here to see what I mean.

(I have the new block selected.) Good, now make sure our new block is selected, and hit the toEntity button. From the entity list, choose func_tankcontrols. If func_tankcontrols is not there, then you don't have the newest .FGD file. Download the newest one from the Files page. As you can see, there is only one key we have to worry about with the func_tankcontrols entity; 'Tank entity name'. If you can remember, we named our func_tank 'turret', so enter turret in the 'Tank entity name' key.

    Hooray! Our turret is finished! One thing remains to be done; we must move our turret into the room that we made. Do do this, simply use the arrow tool and drag a selection block around the whole turret in the top view, and push enter. (Unless you have auto select on, in which case it selects it automatically without you pushing enter.) Now, simply drag our turret into our room. Make sure the turret base is flush with the floor.

Check out this picture to see our turret inside the room.

To make the finishing touches on our level, we have to add an info_player_start and a light entity. Using the entity tool, place an info_player start in the room anywhere you want, as long as it's not too close to the turret. Then create a light entity right in the center of the room both vertically and horizontally. Right clink on it and check it's properties once, just to make sure everything is set alright. The brightness should be 200. Alright! Our map is complete!

Click here to see how the completed map should look.

To see our turret in action, compile the map. You should be standing in the room we made with the turret sitting there calmly. It's time to liven it up a little. Stand right behind the turret, and push the USE key. The turret should aim where you look, and fire when you shoot :-) If the turret doesn't make any noise, doesn't shoot at the right place, or the flames aren't showing up at the end of the turret, go back in the tutorial to make sure you set up the ambient_generic and func_tank correctly. However, if it does work, congratulations! You are a func_tank master! :-)

    Well, that just about wraps up this tutorial. Hopefully you learned alot from this. Let me just mention a few func_tank notes:

  -- Most of the time, you're going to want to cover your func_tank with a clip brush. This is so that people don't block the turret. You'll see a clip brush over almost every prefab turret. I didn't explain how to do that in this tutorial because it would take too long to explain what is really a simple process. If you're not sure what a clip brush is, read Hellbringer's clip brush tutorial back in the Tutorial section.
  -- You might notice in your map that the turret is a little out of proportion (large) compared to the player. I made everything in this tutorial a bit larger than it normally should be just so that it would be easier for you to work with it. When you actually get to making your own map, you'll definately want to make your turret much more detailed and realistic. I do not want to see the turret we made in this tutorial in any future maps, ya hear? :-)

If you have questions or comments (concerning the tutorial, func_tank in general, or otherwise) please e-mail me. Remember that you can grab the example map that I came up with for this tutorial in the Files page. See ya! :-)

Half-Life, and the Half-Life logo are trademarks of Valve Software and Sierra Online, used with permission. All screenshots and drawings of Half-Life are (c) copyright Valve Software, 1998. All rights reserved. All original content (text and art) are (c) copyright Wavelength, 1998, and may not be reproduced without permission.