3D Slices - Cropping
Here a cropping region was created through the context menu. This variable is then dragged onto the mesh slice program to change the connection. As you change the sliders the mesh slice will change, but the iso-surface is still computed from the original mesh.
The cropped mesh is then dragged onto the "Iso surface" variable so that the surface will also be cropped.
At the end, the transparency of the mesh slice is changed. This is on top of any transparency that's specified in the color ramp.