Please note: This thread is about some rather advanced texturing techniques. If you are new to texturing then this probably isn't the place for you.
I have been making my own custom texture sets because I am not really satisfied with any of the default texture sets. Many of the default texture sets are mostly good, but I don't really think that any of them have 8/8 textures that I actually like when used together. While scouring through all of the textures when making my own custom texture sets, I noticed something interesting.
Out of the ~192 current textures, only ~76 of them are truly unique. Now maybe that's a little unfair because the other 116 of them are actually unique (except maybe 2), but only because they have unique color hues. However, the other 116 share very similar or identical "bump maps" with at least 1 other texture. What this means is that while they are different colors, they actually share the same pattern.
Perhaps these pictures will illustrate exactly what I mean. All 8 of these pictures came directly from the editor and are from 8 different textures (from 8 different texture sets). However, as you will see, they share the same pattern or "Bump Map".
+ Show Spoiler [8 Rock Pictures] +
Also BTW, if you've noticed this before, those 8 colors are my guess of where you noticed it from.
There are probably plenty of textures in groups like this that you've probably never seen/though/noticed before (The list at the end of this thread is all about cataloging them). Let's look at one more first though.
+ Show Spoiler [Lava Cracks] +
These two textures have very different colors (and are from different texture sets). One is dark red with very dark cracks, while the other is a brighter red with very bright red cracks. The thing is that the cracks share the same pattern, so you can do some really cool shading patterns with them. While I've known there were many identical bump maps, these two are really what inspired me to make this thread and catalog all of them.
In the following picture, I used exactly two textures, but I blended them in such a way that it looks like there might be 3 different textures there. This illusion is caused mostly because the cracks line up perfectly.
+ Show Spoiler [Example] +
The next picture shows how I used the two Lava Crack textures in my most recently published map.
+ Show Spoiler [Real Example] +
There are other uses for this... like making a certain texture one color on one side but having it blend to a different color on another side (without any bump map interference). Or you can make a set of tiles where some of the tiles are a different color than the rest of them (again without any bump map interference). There are probably other uses and I'll leave it up to you to figure them out.
If for some reason you don't think any of this valuable and that you wont use this information that I spent over 20 hours researching... That's fine. I didn't actually do this for you. I did this for myself, and I am posting it so that I never lose it (Also, I learned and memorized a lot about textures in the process). But if anyone in the community finds this information useful then this gets a 10/10 on the "worth it" meter. I took care to present the information properly just for you ^_^
I like to think this is intuitive enough to not need a legend, but if it does let me know and it'll go here.