What type of light mapping allows for fast path-tracing and provides significant updates in Unity's editor?

The key to understanding why progressive light mapping is the most suitable choice lies in its ability to efficiently handle real-time updates while still providing high-quality results. Progressive light mapping is designed to allow for fast path-tracing, which means it can simulate how light interacts with surfaces in a scene much more quickly than traditional methods. This attribute makes it particularly effective for developers who want to see immediate feedback while making adjustments to their scene during the development process.

In Unity's editor, progressive light mapping generates lightmaps progressively, meaning that it improves the result incrementally as it processes the scene. This feature enables developers to visualize changes in lighting as they happen, facilitating a more interactive and responsive workflow. While baked lighting can produce high-quality results, any changes to the scene would typically require re-baking the entire lighting setup, making it less efficient for iterative design.

Although light probes can be useful for dynamic lighting scenarios, they do not provide the same level of detail as lightmaps when working with complex light interactions. Fixed light mapping tends to lack the flexibility and speed that progressive light mapping introduces.

Overall, progressive light mapping represents a modern approach to managing lighting in Unity, combining the quality of baked lighting with the efficiency necessary for rapid iteration during development.