Shear tool pallet with three choices is gone in CS6 and CC2018.
When using the shear tool I am not getting the three options anymore. Usually a box pops up with distort, perspective and one other I never use. I went back to my CS6 to find its not there either. I'm hoping this is just something in preferences I missed. I use this tool a lot, especially the perspective mode. The transform tool doesn't seem to offer independent corners as I need, it just keeps moving like any regular bounding box. I did find something in effects but you have to work blind if you are tying to set the object's perspective to something you've already placed on the file.
