OK, so this is about putting two tex on the same prim..... well, actually its a cheat, it looks like two tex on one prim, but actually its two tex on two different prims. I will talk about why you would want to, later, and give some examples.
Here's how its done
First rezz a prim and put your base tex on it
Then make a copy of that prim
Put your overlying prim on the copy. It is usual to use an alpha tex for this, although you can use a normal prim and turn up the transparency on it, so you see the underlying prim through the top tex.
I have used a green wavy tex...
Then, in Objects increase the size of the overlying prim so its about 3 to 5 mm larger in all direction.... so...in this case, the original prim is 2x2x2, and the copy is 2.005x2.005x2.005.
Move the copy down onto the original prim and locate it with the same centre as the original.
I dont like the green tex, so I change it for one with purple spots.
Then I decide to repeat the whole thing with a third tex.
Another alpha tex
Thats more like it. An attractive and rich texture.
You are very welcome to take a copy and upload it SL if you like, it would look good on fabrics, i.e. a carpet, tree bark or whatever you are building at the moment. I will show you briefly, in a later blog what it looks like as clothing.... (have to make it first).
So... WHY BOTHER.....:))
Well, I can now change the colour on all three layers.... that gives me great possibilities.
One or other ( or all three) layers can have rotational scripts added.
I use it for.... moss or grass on rocks.... blurring the underlying tex when its too crisp...... or adding colour I need for the whole composition.
SCULPTIES... the same principles apply... but remember that some sculpties change rotation slightly when you increase the size of the copy. This is due to them not being true to the x,y,z axis.... lots of fiddling about may be needed.
Hope this is useful....