We’ve just published a comprehensive expert guide (PDF) on advanced techniques to create high-quality light fixtures for real-time applications. Read it and find out how you can use light cookies and advanced shaders to create convincing artificial light sources in any project, from games or architectural visualizations to films and more! Wait a minute, what are light cookies? These are 2D textures or cubemaps used to block parts of a light source in order to control the shape, the intensity, and the color of the emitted lighting. They can also be called “gobos”, “cucoloris” or “flags”, depending on the industry and their use case.
With their help, you can efficiently simulate ray-traced soft shadows, colored transmission, and even refractive caustics! Indeed, rendering these effects fully in real-time would be remarkably expensive in densely-lit environments, even for the most powerful GPUs on the market. This is why baked light cookies are still crucial to produce convincing lighting in real-time scenarios.
Good news: the Built-In Render Pipeline can also take advantage of (grayscale) light cookies! Therefore, you can also reproduce high-quality shadows on platforms incompatible with the High Definition Render Pipeline (HDRP), in real-time.
After pointing out some of the common lighting mistakes still found in CGI nowadays and giving you recommendations on how to prevent them, the expert guide walks you through all the steps required to generate beautiful noise-free cookies with a variety of 2D and 3D programs, such as Photoshop, 3ds Max and Unity itself.
Moreover, I will explain how to set up critical post-processing settings in Unity, such as Exposure and Tone Mapping, so that your interior scenes can be lit in a more physically-correct way, one of HDRP’s mottos.
Then, the guide gives an extensive review of the crucial Light properties in HDRP, such as the physical Intensity units, the Color modes, the Shadows parameters, and the Light Layers used to restrict lighting to specific objects. Later, I present different methods to replicate the lampshade of a chandelier with HDRP’s highly flexible Lit shader.
Finally, I introduce an original workflow to generate appealing caustics to bring the final ultra-realistic touch to your light sources, by adding micro-details to simulate the self-reflections of the light fitting and the structural imperfections found in the reflectors and the lampshades.