[Tutorial] Basic texture editing with a GIMP 2 instead of TexBlend

[Aequus]

I hope this manual will be helpful for people who are usually using TexBlend to apply various png overlays to their textures.
Though TexBlend is wonderful and really easy-to-use tool, especially for a novice, there is a couple of flaws at how it works:

 

Issue #1: Resulting textures has the same resolution as the png overlay.
Just imagine, like you have one of those extremely detailed 8192x8192 diffuse maps from ThePure/Demoniac/Bjin/whatever texture sets. It looks great, but you want to attach some pubic hair or different color for vagina or nipples using TexBlend. The truth is, most png overlays has the resolution as 4096x4096 or 2048x2048, so after you blend the texture and the overlay together, you'll see that resulting texture had shrunken from 8192x8192 to 4096x4096 or even less than that, depending on the overlay applied.

 

Issue #2: TexBlend's textures are always has 24bit RGB8 format, that is pretty much uncompressed. You cannot choose the type of compression.
The uncompressed hi-res textures were originally created for better quality as references and probably for people with hi-end hardware to play with. For example, original ThePure diffuse map with a resolution 8192x8192 compressed as DXT1 and it's file size is roughly 42 Mb. If you apply some 4096x4096 overlay to this texture, the resolution will shrunken to 4K, but the file size will be roughly 50 Mb! Lower resolution, more GPU memory used... Kind of sad, eh? Besides, there is no point to turn DXT1 texture into uncompressed. The quality of already compressed texture will not change that way.

 

So in short, what this manual covers?

1. How to rescale png overlays using GIMP 2.
2. How to edit hi-res texture without resolution loss.
3. How to compress/export dds textures using GIMP 2.

 

Required tools:

1. GIMP 2
2. DDS plug-in for GIMP 2

You can find everything here, along with an installation guide:
https://www.youtube.com/watch?v=21-U-4Ul4zM

 

Step #1: Rescaling png overlay to match texture resolution
1. Start GIMP 2
2. Press "File" -> "Open..." in main window of GIMP 2.
3. Browse your folders and find the overlay you want to rescale. Select it and press "Open" button.
4. After an overlay file is loaded, press "Image" -> "Scale Image..."
5. New window named "Scale Image" has appeared. You can change overlay resolution by editing two values: "Width" and "Height". Edit them to match texture resolution. For example, if you want to edit 1K, 2K, 4K or 8K textures with this overlay, set the values as 1024, 2048, 4096 or 8192 accordingly. After values is set, press "Scale" button. The program will ask for confirmation, press "Scale" button again.
6. After rescale process are completed, you can either save this overlay using "File" -> "Overwrite" or "File" -> "Export As..." options. However, if you decide to export the overlay, make sure to use the file format that supports alpha channel (I suggest to leave it as png image). Just do not export it as jpeg or something like that. Aside from that, go on with default settings while exporting overlay.

 

Step #2: Merging the overlay with the texture
1. Load the dds texture you want to apply an overlay on into GIMP 2 using "File" -> "Open..." command.
2. Load the png overlay you're previously changed. Make sure you're loaded it into different window.
3. Press "Edit" -> "Copy" or "Edit" -> "Copy Visible" (doesn't really matter now) in png overlay window.
4. Move to dds texture window and press "Edit" -> "Paste". An overlay should appear in a moving frame over the texture.
5. Now press "Layer" -> "Anchor Layer" to merge the overlay with the texture.
6. It's almost done! Off to step #3...

 

Step# 3: Saving the dds texture
1. So, you have successfully edited your texture. Press "File" -> "Export As..." to continue.
2. Name your texture whatever you like or leave the old file name. The file extension should be .dds (well of course).
3. Press "Export" button. The window named "Save as DDS" should appear. There are several compression methods here. I suggest to use compression or format type the original dds texture has. For Skyrim, most common compression types are DXT1, DXT3 and DXT5, uncompressed formats - 24bit RGB8 and 32bit RGBA8. Make sure to choose "Generate mipmaps" into "Mipmaps" field. Oh, and if you want to know the exact type of compression the original texture has, use some programs like WTV DDS File Viewer that show their full properties.

Thanks for reading, hope this information was helpful.
P.S. And I hope you'll pardon my stupid English.