Global illumination

- [Instructor] Global illumination, or GI,…generally means any rendering method…that models the transfer of light among surfaces.…The first generation of rendering technology…uses a simple model, local illumination,…in which each surface is lit separately.…We still use local illumination…for draft and interactive renderings,…but for photo realism, we must enable GI.…The second generation of renderers offer basic forms of GI,…such as ray traced specular reflections.…

Diffuse reflections, or bounce light,…is handled by various methods, such as radiosity meshing,…irradiance mapping, and final gathering.…But these various forms of GI…work independently of one another,…and these rendering methods require expertise…and lengthy setup time to achieve best results.…Today we're in the third generation of rendering technology…with unified path tracing, brute force GI,…and unbiased rendering.…

These various advancements enable designers and engineers…to save valuable production time…and focus their attention more on the project goals.…