_(Note: Please be sure to read this entire tutorial completely before attempting your custom texture/image creation. Please do not follow along step-by-step without first reading this entire tutorial.)_
• Find or create a texture/image that you want to use in Hammer World Editor. Make sure that your texture is in one of the following resolutions (pixels): 1x1, 2x2, 4x4, 8x8, 16x16, 32x32, 64x64, 128x128, 256x256, 512x512, 1024x1024, 2048x2048. Ideally, your texture/image should be in Targa (.TGA) format.
To texture a block that is 128 units by 128 units, the dimensions of your texture will be 512px by 512px.
• When you have a texture/image ready to import, launch the program named VTFEdit (to download VTFEdit CLICK HERE).
• Once you have opened VTFEdit, click on FILE and then IMPORT and import your texture/image. [refer to image below]
• If you are presented with a window that says VTF Options, make sure that the "Resize" box is NOT checked, then click OK. [refer to image below]
• At this point, we will be saving this texture for use with Hammer World Editor. Now click on OPTIONS and make sure you have Auto Create VMT File enabled. [refer to image below]
• Select FILE and then SAVE AS. Name your texture and Save as type: VTF Files (*.vtf)
Save your custom texture/image into your custom Materials folder, which can be found in the directory I will list below;
C:\Program Files (x86)\Steam\SteamApps\common\Day of Defeat Source\dod\custom\my_custom_stuff\materials
(Note: Saving your file into this Materials folder is a crucial step in this process. If you fail to save your file into your Materials folder your custom texture/image will not function properly.)
• When you save your texture VTFEdit will create two files. One file is your VTF and the other file is your VMT.
If you have followed all of these instructions properly, you have successfully learned how to create your own custom textures for use within the Hammer World Editor.