This action comes with good default parameters. If you want to change them, you will need some experimentation. The best way to study this action, is to put all values on zero and try them one by one. With this you can create slick effects for thumbnails such as shown in this tutorial.
This action is very slow. Please downscale first your image as much as you can!
You can enlarge your image or make it smaller. If you want to only do this and not apply any shear or perspective effect, you can better use the action [[action-scale | Scale]].
Left Shear Angle
Top Shear Angle
The shear angle taken from the left or top edge of the image. If you use only these options, you will only get a 2d transformation known as "shear mapping".
Bottom Shear Factor
Right Shear Factor
With these numbers you can apply a shear effect from the bottom or right edge. Note that these value is not angles. As soon as these values are not zero, you start rotating in 3d. If only one of them has the value 100 (and all other zero), there will be a corner in exact the center of the image.
The colour of the background which will appear.
This background colour won't appear if the opacity is zero.
The opacity of the background colour.