As far as we can tell from posts here on the forum, Easel is only for 2D carving, unless your loading a 3D gcode file in and using it as a gcode streamer. If you use a Vbit, you could simulate 2.5D carving in Easel, but the toolpaths would still only be Z axis 2D depths of cuts. .
Is this is what you are referring? It's only 2D also.
We have few different laser diode engraving machines here. From 2W-6W and they are controlled with an analog modulated driver with Z,A,B,C or S commands depending on what controller we use. Our PicEngrave Pro 5 will interpret the shades into settable depths of cut for spindle use, or for laser power and can generate those commands and more. There are many ways to manipulate the colors/shades in an image to get different results.
We also have a 3040 CNC with a 4th axis that we can laser engrave images on round materials. PEP5 will also generate 4 axis toolpaths for using with a spindle or laser in Mach3.