LightTools is a complete optical design and analysis software product featuring virtual prototyping, simulation, optimization, and photorealistic renderings (including source-lit renderings) of illumination applications. LightTools facilitates innovative designs for a broad range of solid-state lighting applications, including interior and exterior vehicle lighting, fiber light engines, complex light guides, projection systems, machine vision systems, solar collection systems, and more. LightTools combines full optical accuracy, powerful optical and illumination analysis features, and an intuitive, interactive graphical user interface in a 3D solid modeling environment. Real models, "sculpted" in software, interact with rays simulating the light to produce virtual prototypes of manufacturable systems. LightTools' Monte Carlo ray-tracing facilitates accurate spectral modeling of the illuminance, luminance, intensity distributions, and CIE colorimetric data anywhere in the opto-mechanical model. Volume-emitting or surface-emitting light sources of various pre-defined shapes can be easily created and even combined with mechanical and optical parts to form models of lamps, light bulbs, LEDs, and other illumination devices. The LightTools SOLIDWORKS Link Module, a direct link between LightTools and SOLIDWORKS, delivers a streamlined and user-friendly engineering environment for optical and mechanical design teams. This module enables designers to link SOLIDWORKS mechanical models to LightTools, where they can assign optical properties, optimize, and directly update their SOLIDWORKS models.