The Modify section is placed in the middle of the Texture tab sheet. It consists of a combo box and three sliders.
This combo box offers six options of which the first item "No Rotation" has no effect. The other five options let you rotate or mirror the texture. 90 rotates the texture 90 degrees clockwise, 180 rotates the texture 180 degrees and 270 rotate the texture 270 degrees clock wise or 90 degrees counterclockwise. The "Flip" option mirrors the texture vertically (or with other words: rotates it by 180 degree and mirrors it horizontally) and "Mirror" mirrors the texture horizontally.
Please note that the effect of the 90, 180 and 270 options can also be achieved with the Rotate slider of the Zoom/Rotate section, but the calculation will take much longer. So it is wise to only use the Rotate slider if you want to select a non-rectangular rotation angle in this case.
Small Cut Off value
High Cut Off value
The cut off slider lets you remove parts of the texture. It cuts off the texture at the right and bottom edge decreasing the width and height of the texture. The default value of zero means that nothing is cut off. Moving the slider to the left cuts off more and more.
Offset X / Offset Y
Small Offset values
Offset values at 50%
The two Offset sliders shift the texture in horizontal and vertical direction without breaking the seamlessness of the texture. If you have the Show Grid check box activated, you can see the effect more clearly. The white grid will shift according to the slider movement. These sliders are useful for positioning the texture effect precisely over an image area.