To create a dimensional depth on a substrate, use grayscale to represent different depth levels. This can be done in most design software like CorelDRAW or Adobe Illustrator. Darker parts will be engraved deeper than the lighter areas to create a 3-D engraving result.
To bring convenience to laser engraving users, there are laser engraving machines on the market that can create 3-D engravings from a grayscale graphic file at the touch of a button. With this capability, just think what you can do.