When stenciling and texture painting, how do you select the texture to make it active, the one that you want to paint on?
uv image editor.
To Texture Paint
- Select Your Object
- Split the window into two panes
- Set the new window to UV image editor.
- Select a texture or create a new one.
- Press Texture Painting Button
To make the texture active, just select all the faces and load/select the texture you want active in the UV/Image editor
Just make sure that the terrain/object is always UVmapped to the stencil you are currently using.
Heres and example .blend: http://www.mediafire.com/download.php?1wzulmmyamm