Implement invalid sample points filling. Improves invalid regions
but introduce light leak.
Grid sample points are considered invalid if they have a ratio of
front-face ray hit under the given threshold. This is a post-processing
pass on the baked lighting that fills dark regions produced by
invalid sample location (e.g.: inside walls) with valid neighbor
samples data.
Two new parameters are added:
- Dilation Threshold: Validity threshold under which grid samples are
considered invalid. Invalid samples will gather valid lighting data
from valid neighbors inside the dilation radius.
- Dilation Radius: Radius of the dilation process. Expressed in grid
sample distance.
The validity of each point is progressively refined just like the
lighting data during the baking process.
The dilation process is implemented as a post-processing pass during
the loading of the grid data into the irradiance atlas. This allows
live tweaking the dilation parameters.
Pull Request: https://projects.blender.org/blender/blender/pulls/110386