Is there a way to control the opacity of textures? I am looking for a better way to blend textures.
Yes.
With practice you can apply thin or thick coats of texture. It depends on three factors.
a) The “radius” of the spray pattern.
b) How fast you click the left mouse button when spraying the texture.
c) Where the cursor is placed on the terrain.
Here are three examples (using VAVballast and oz dirt)
1. Very (very!) quick and light click on grid intersection.
2. Very quick click on grid intersection.
3. A normal click just to the right of the grid intersection with the “radius” increased as little from minimum as is possible.
The “radius” isn’t round. It will spread in a jagged pattern, fading at its edges. Its shape and spread will vary greatly depending upon the position in the grid where the spray is placed.
It is not possible to always get the transparent look exactly where you might want it, but I find that with a bit of trial and error and use of the Undo button it usually works out OK. It’s well worth practicing on a spare bit of baseboard to see what can be achieved.
Cheers
Casper
Edit: I’ve just noticed the addition of “TS12” to your question which you edited whilst I was putting together this reply.
Hopefully the above will be relevant. If not, perhaps it will be of some use to other members.