The rectangle represents the position and orientation of the texture image. You can move, rotate and scale the rectangle to place the texture exactly the way you want it.
Use your mouse to move/rotate/scale the texture; it works the same way like the
Arc Rotate tool does. You will find everything about Arc rotate in the manual (click the link above...)
Very shortly:
- Use the left mouse button to rotate the rectangle
- Use the middle mouse button to scale it
- Use the right mouse button to move it
- Click inside the circle to handle the X and Y axes, click outside the circle to handle the Z axis.
- Click the top/bottom square for Y axis only, click the left/right square for X axis only...
