Making glass doors in Kingpin is a little more difficult than it should be. Now the game is not made to have moving transparent brushes so that people will just have to go round that problem. Now what you can do is put textures with an Alpha Channel (Alpha Textures) in a door and unlike just putting the Alpha surface flag, you can achieve a transparent look. An example of that is the blood stain that appears on the truck in the cut scene of the dock level which is done with a trigger_spawn-ing func_wall. 

Now I've come up with two ways of making the glass door. The first one is more reliable but looks a little bad because the whole door has an Alpha texture. The second one looks great but malfunctions when the cast open it. I haven't managed to make it malfunction myself, though so it should work fine in DM. All this malfunctioning is caused by the fact that there are two doors with one triggering the other. Note: I'll be using func_door_rotating-s for both examples

Lets start with number one.

First you need to make the frame of a door; don't make it too complicated. then make a brush that will be the glass just like a normal door, covering it with the special glass Alpha texture. Then the origin texture brush and bind them all into an entity. Then go to the entity properties (N) and check the SURF_ALPHA box.

Make your entity look something like this

Make sure you have the Alpha Surface flag unchecked and the texture MUST look absolutely opaque in the editor even though it becomes transparent when you select it. Well that was fairly easy. If you want to find out how to make your own Alpha Textures then click here.

Second One

This one is a little harder. To start you need to make just a door frame. This door will be targeted by the other one but it doesn't really matter which one is the targeter. I have found that it is easier to hit the glass plane door (2nd) with the use key. Of course you won't be able to open the targeted door with use.
Set the following entity properties apart from the other things like angle and distance.

Set the SURF_ALPHA to off (unchecked)
Put a targetname. For instance door1.

Make sure that the style is one because otherwise the mess will be complete.

And now for the glass plane. You can't go with only one origin texture brush. Put the glass texture and set the SURF_ALPHA flag and make the other fields like distance and angle and style THE SAME as the first door. But instead of targetname, here you will put target to door1.

Everything should work now. If you have any trouble then download the zipped map file and bsp from here.

Making your own Alpha Textures

Now I've tried with many programs but few recognize Alpha Channels. Wally finds them but says that it doesn't support them yet. So I use Paint Shop Pro. It's fairly easy there. You just need to make a mask of the image and turn the mask into an Alpha Channel. Refer to the PSP help file.

In order to make this example actually work you need to download this texture and put it in the sprites directory of your Kingpin main textures directory.

As I mentioned before there are some drawbacks. In the first door, because the whole door has SURF_ALPHA, you can see other brushes through the frame without it being transparent. In the second one, half of the door stays open for longer when the cast opens it. I don't know why that is. And with both doors you can shoot bullets through the glass because it acts just like the net fence for instance.

My suggestion is that you use the second door in Deathmatch levels because there is no cast. I also think everything will work better if you make just normal func_doors.

Suggestions and comments, etc. to :
oggie_k@yahoo.com