A technique is provided to model a heat penetration profile for various targets which are non-planar or three-dimensionally shaped targets for use in a heating system. The relative volume of material that is irradiated at various depths may have an impact on the absorbed heat profile through the target. For example, a hollow cylindrical product has substantially more material per micro-meter near the outside diameter than it does near the inside diameter. Accordingly, the thickness of the wall or the diameter of the hollow inside the cylinder, as well as the outer diameter of the cylinder, have a substantial impact on the ultimate heat profile through the wall.