Since others have described what it does, I’ll just say why I find it useful.
Texture lock off is handy if you are cutting/cloning/moving stuff and you want to have the textures match up over a large area.
For example, imagine you are making a wall out of a brick texture, which has various corners and variations in it. A simple way to create this is to make one section, then clone, move the cloned piece to one end, adjust it as required, repeat. If you leave texture lock on, each section will have an ugly seam. If you adjust the texture on the first section, and then turn texture lock off for moves (shift + T) and rotations (shift + R) then the texturing will all line up, without additional adjustment.
If you do your initial construction with texture lock off, most of the texturing will be close to it’s natural (i.e. unmodified texture coords) position, thus leaving you with less alignment work to do.
Texture lock on is good if you want to completely clone some specific part.
The state of texture lock is indicated by the letters following L: in the status bar. R = rotation lock M = move lock.
what entity window? The one you get to via ‘N’? or some other?
Yeah, the N one. Important points:
- entity and key/value descriptions
- list of key value pairs
- angle key / angle buttons instead of trying to use brush rotation commands