You can use any photo software to make the loading image. I will leave that part up to you. You'll want to make it 24bit target ( .tga ) and a size of 1024x1024 pixels.

Save the file to [root]\texture_assets\loadscreen_[levelname].tga [root] would be the default game path where the games .exe files are located [levelname] is the name of the bsp for the level. If you do not have a folder named "texture_assets" create one. This folder will be used for all your custom images.

In my example I used the test level called mp_test that was included in the mod tools. In my example I saved the loadscreen image to the following:

Creating Material

Creating a material in the game using your custom targa image

• On the 'applications' tab of CoD4CompileTools click on the "Launch Asset Manager" button to launch the Asset Manager program. Now open the file "[root]\source_data\levels.gdt". Example: At the top click the word file in the drop down menu then open next navigate to source_data folder now click levels.gdt. You should see there is already a level entry for map names "test" and "mp_test" but we'll come back to those in a minute. Scroll down the list of asset types in the upper left and select "Material" in the list, then click the button "New Entry". You will be prompted to enter the name of the new material you are creating. I named mine "loadscreen_mp_test" without the quotes. It must be named loadscreen_[levelname]

• First, change materialType to 2d. This will remove a lot of options that aren't needed for 2D materials. Next, set surfaceType to , and usage to .

• Because this is a loading image only, we do not need it to have a surface type to indicate bullet impact fx and sounds, and we also do not need it to show up in the editor. We don't plan on using this material on any world geometry.

• The default blend options should be fine, but make sure yours match the ones in the image below to make sure.

• For color map click the "..." button and select the tga image you made in the previous step. Set it to no tile, nomip bilinear, and check the nopicmip box.

Once you have the settings like the image below continue reading.

Asset Manager Loadscreen Creation

• Now that you have all the settings correct lets make sure the material converts properly without any errors. Click "PC Convert" -> "Current Asset Only" from Asset Managers drop down menus. This will convert this asset in a command line window and show you the results. If you have done everything correctly up to this point it should say that converted the material and finished without any errors. Here is my example below.

PC Convert

•  You might notice that the material has been converted to .iwi format and new files have been created:

When you package the map into a .iwd file you'll want to include the .iwi file. The others aren't necessary to be in the .iwd because they will be contained within the fast file for that level.

Tell your custom map to use the new material

You have now successfully created a material that the game can use as a load screen. We just need to tell the game to use that material when loading your map. You should still be in Asset Manager in the file levels.gdt. You can now select "level" asset type from the list. You should see those two levels listed there as we did when we first opened this file. You'll want to click the "New Entry" button here to create a new asset of type "level" in this GDT.

• Type in the name of your level ( it must be exactly the same name as your bsp ) and click ok.

• There are just a few settings we need to set here. First is the bspName. In my example I set it to "mp/mp_test" because that is the path and filename to my bsp. Example: mp/mp_yourmapname

• This is a MP map so I don't care about victory or defeat materials so I'll just enter some generic materials used for that.

• Now "MP Level Load Material" is the one where you'll specify the custom material you just made in the previous step. In my example I created "loadscreen_mp_test" in the previous step, so I'll enter it here.
 

Asset Manager

• Save the GDT Example: go to file then select Save from the drop down menu now you just saved the level.gdt. Now close the Asset Manager and go back to the CoD4CompileTools click "Run Converter" under the "Applications" tab. Converter will run and convert the level asset you just created. You shouldn't get any errors if you did everything correctly, and a new file should have been created:

My example I created was: raw\maps\mp_test.csv

This csv file tells the game what materials to use when the level is loaded. You should never edit this file directly. Always make the changes in Asset Manager and then run converter.  

*Note since the 1.5 patch, the images and .csv files have to go into your .iwd pack; The game will no longer load the loadscreen from the raw files. The .csv file isnt needed in the newest patch.

Adding it to your map

Now update your zone file and add this line:

and add the .iwi file, which can be found in '[root]/raw/images/loadscreen_[mapname].iwi', to the package.

You can now rebuild your Fast File, move it into the usermaps/[mapname] directory, together with the [mapname].iwd file, and run your map. You should now have a working loadscreen. 

Move the mp_yourmap.iwd  and your fast files to a folder called "custommaps" in your mod folder. The fast files can be found in '[root]/zone/english/mp_yourmapname.ff and mp_yourmapname_load.ff

Now  back to the CoD4CompileTools under "Level Compiling" Checkmark Use Custom Command Line Options at the bottom and add these lines:

Now you can click #5 "Run Selected Map"

The .IWD file 

An .iwd file is simply a zip file, with content for CoD4. It should only contain custom images and sound files, the rest will be packed into the Fast File.

Simply follow the directory structure as listed in '[root]/raw/'. For custom images: make an 'images' folder on your desktop, put all .iwi files that are custom into this directory (.iwi's can be found in '[root]/raw/images/'). Each custom texture consists of 3 files, the colour map, the normal map and the specular colour map. All 3 of these should go in your 'images' directory. Note that the specular colour map always has a weird name, like '~roof_concrete_tile_01_spec-r~a371169a.iwi', where a color map is just 'roof_concrete_tile_01.iwi' (and a normal map 'roof_concrete_tile_01_nrm.iwi'). For the loadscreen and compass_map textures we just have a colour map. Dont worry about these "'~roof_concrete_tile_01_spec-r~a371169a.iwi'" if you have not created any custom images other than the minimap or loadscreen.

Now go to the parent directory, right-click on the 'images' directory and make it a zip file. Be sure that inside the zip file, there should be a directory called 'images' with the custom textures, the custom textures should not be directly in the zip file.

This .zip file should be renamed to [mapname].iwd and be placed into '[root]/usermaps/[mapname]/'.

.arena, .gsc and .csv files should NOT go in the .iwd file! .arena files don't work in CoD4 anyways, but the other 2 files are included in the Fast Files already.

Example using Winzip right click on the image folder select add to zipfile add to new archive should look like:

Rename images.zip to mp_yourmapname.iwd then click add you done congrats.

Good Luck