The key to displaying only the layer you need is the Zmin value. I don't know just how much you know about overviews, so I'm going to write all steps down.
- Load the map, remove bots if necessary
- Open console
- type "sv_cheats 1" (w/o "", of course)
- type "dev_overview 1"
- type "restart" - the map will restart, and you'll find yourself in overview perspective.
- open console again, type "hud_draw 0" to get rid of all annoying HUD icons.
- Before changing anything, zoom and move to the best distance / position. Very often you will see areas in the overview that only exist for optical reasons, but are not accessible for players. Use your movement keys to scroll around, fire & special weapon function (left & right mouse button by default) will zoom in & out. Once you have a position, DON'T TOUCH ANY OF THESE KEYS / BUTTONS!!! YOU WILL NEED THE EXACT VALUES!
- Once you have perfectly positioned the overview, you can zoom up or down by changing the Zmin value. On a standard config, this is done with the keys [-] (decrease) and [ä] (increase) on a German KB (1.5 console). This corresponds to [/] and ['] on a US KB, I think. Anyway, it's the bottom right key on the main KB section and the key on top right of it, next to the return key. Keep the key pressed to continually increase / decrease Zmin.
- Take screenshots of each layer you need.
- Write down the other values: You need "Zoom", the FIRST TWO numbers in the bracket behind "map origin", "Zmax" and "Rotated".
- Open the txt file of an existing overview, rename it to the name of "your" map. Now overwrite the values as follows:
Code:
// overview description file for fy_neighbours.bsp
// Change the title to the name of the map you made an overview for.
global
{
ZOOM 1.99
ORIGIN -285.70 17.19 -217
ROTATED 0
}
//Ok, in the first line ("zoom"), enter the zoom value from the console.
//In the second line ("origin"), put the first two numbers behind "map origin" in the first two positions
//In the third position of the second line, enter the Zmax value you copied.
//In the third line ("rotated"), enter the "rotated" value from the console.
layer
{
IMAGE "overviews/fy_neighbours.bmp"
HEIGHT -217
}
//Here it's VERY important that you enter the correct file name in the first line ("image"). Otherwise, a wrong overview will be loaded.
//In the second line ("height"), enter the Zmax value a second time.
There you are, the rest is Photoshop... ;o)
Oh, and a little side note for overview makers who don't know it: There's really no need to make a TGA overview. Why not? Isn't true colour nicer? Yes, it is, BUT: Most overviews don't need 16.7 M colours!! The reason why they look so shitty as 256 colour BMP is that ppl just reduced colour depth according to the standard windows palette. However, with Photoshop, you can change the palette to "perceptive". After doing so, Photoshop will pick those 256 colours that are best suited to display the image in really good quality. The only danger is that that green background colour that's transparent in game (RGB 0,255,0) gets slightly changed, too. This would result in a green OV background in game! However, you can easily change this because Photoshop also offers the possibility to determine certain colours that won't have their values changed. I'd put black (0,0,0), white (255,255,255) and said background green (0,255,0) in there, and you are set.
Hope this has been a bit of help.
[EDIT]
Oops, almost forgot about hostage / bomb indicators!
Well, there are no map elements that indicate hostages, so I guess you'll have to remember where they are and photoshop something into the overview.
As for bomb spots, just take the bomb zone part from a layer where the markings (if any exist) get displayed and paste it into the corresponding layer in Photoshop, or again just add some text like "bomb1". It's easier to spot anyway, especially on a dark overview.
Oh, come to think of dark overviews: If there are dark corridors on the overview, those will be awfully hard to see in game, with the black background & stuff. That's why I prefer a bright-coloured outline around each layer, with different outline colours indicating different layers.
I've attached an example overview I made some months ago, when I had enough time for such stuff... 9_9 it'll show what I mean.
[/EDIT]