Found a bug in Global Distance Field

I found a flickering issue in the Global Distance Field. When the number of modified distance field bounds is large, flickering appears.

After digging into the code and global variables, I discovered that a full recapture of the distance field causes the flickering.

The flickering happens in these cases:

- When NumCulledPrimitiveModifiedBounds exceeds 1024

  • When r.AOGlobalDistanceFieldForceFullUpdate is set to 1 (forcing a full update)
  • When r.AOGlobalDistanceFieldPartialUpdates is set to 0 (disabling partial updates)

UE5 version: 5.5