GFXTrans takes the active selection or layer and rotates it the specified number of degrees. You can choose to rotate the preview by hand or type in a specific angle. Rotations can be turned into new layers or anchored to the existing layer. A series of rotations can be performed to create an animation or special effect.
Table of Contents
- A tour of the GFXTrans dialog window
- Animation Options
- Interactively changing the rotation angle
- Reset
- Performing the rotation and closing the dialog
- Undoing the rotation
A tour of the GFXTrans dialog window
Starting with the upper left of the GFXTrans window you will find the Rotation Angle Preview. This is an interactive display that you can use to adjust the angle to rotate the active selection or layer. More about this feature in a moment.
GFXTrans main window showing a thumbnail preview of a layer generated using the GFXShapes plug-in, the initial rotation angle (in Graphics Muse red) and the animation offset angle (in gray).
To the right of the Preview are the feature options for GFXTrans. The first option is the Layer to Rotate menu. Any layer from the currently active image (the one from which GFXTrans was started) can be rotated by choosing its layer name from this menu. When a new layer is chosen, the Preview is updated with a thumbnail sized version of the layer contents.
Below this menu you will find a box titled Disposition of Rotation. In this box are two options, one labeled New Layer and one labeled Anchor To Original. Right before a rotation is performed a floating selection is created. These options determine the disposition of that floating layer after the rotation has completed. If you choose the New Layer option you will want to specify a Blend Mode and Opacity for that new layer using the options just below the layer disposition frame. Note that the blend mode and opacity options are not active (and are not used) if you choose the Anchor to Original option.
To the right of the layer disposition options is displayed the Angle to Rotate the selected layer. You can either enter an angle manually by typing it in the white box, use the arrow keys to move up or down by 1 degree of rotation through a range of 0 to +/-359 degrees, or simply use the grab box in the Preview window to interactively change the initial rotation angle. Note that angles may be entered up to 1/1000th of a degree, though angles less than 1/64th of a degree are computed identically by the GIMP.
Below the Angle to Rotate is a button labeled Smooth Jagged Edges. If selected this will cause the rotated floating selection to have its edges smoothed (also known as anti-aliased). The effect of this smoothing is not obvious in all rotations so you may need to experiment to find out if you need to use this option
Just below the Smooth Jagged Edges button is a field for specifying the Base Name for new layers. The default value is GFXTrans with a number added for any layers after the first. The base name field becomes useful if you are generating a series of rotations for an animation or special effect.
Two fields are provided for animated rotations: the Number of Frames for the animation and the Angle Offset for each frame. Animation occurs by creating a series of layers, each slighly modified from the previous layer. To get multiple layers, each slightly more rotated than the last, the number of frames must be larger than 1. The angle offset for each frame is separate from the initial Angle to Rotate. The former is displayed as a gray region in the Preview frame. When you click on Apply, the first rotation will be at the initial rotation angle and all subsequent layers will be rotated an additional amount equal to the angle offset for each layer.
Interactively changing the rotation angle
The Preview window can be modified by clicking inside the frame and dragging the mouse in any direction. As you drag the orange box will rotate within the black circular outline, with the blue line and drag box always pointing to where the current layer's upper right corner will be after the rotation.
When the left mouse button is clicked and held, mouse drag operations cause large changes in the angle of rotation. You can modify this by using the Shift and CTRL keys. Holding the Shift key down while you drag will decrease the angle rotation by 1/3rd, the CTRL key will decrease it by 1/6th and holding both down will decrease it by 1/10th. This should provide fairly reasonable levels of granularity in the rotation, with even finer levels achieved by using the arrow buttons.
All fields and original settings of the dialog can be set to their initial (default) values using the Reset button. Clicking on this button also will refresh the Layer menu to show all the layers in the current image (the image from which the GFXTrans dialog was opened). This is useful for doing rotations of layers that have just been created by GFXTrans.
Once all settings are complete, click on the Apply button to perform the rotation. The Layer menu will be updated automatically and the Canvas window will show the rotated layer.
Performing the rotation and closing the dialog
To perform a rotation click on the Apply button. You need not make any changes to any other part of the plug-in before doing so. In this case, you will simply get a new layer that contains either the current selection or a copy of the active layer.
The GFXTrans window does not close automatically. It will remain open so you can peform multiple rotations if you desire. To close the window, select the File->Quit menu option.
GFXTrans performs all its work in a single level of undo, which means you can undo a single rotation with CTRL-Z. Similarly, a series of rotations done using the animation options can also be undone with a single CTRL-Z keypress.
