What you're seeing
Virtual shadows show checkerboard corruption, disappear, or become invalid while the engine reports page-pool overflow.
Likely causes
- Requested Virtual Shadow Map pages exceed Max Physical Pages.
- Too many lights request high-resolution virtual shadows at once.
- Shadow resolution is too high for the allocated pool and target GPU memory.
Check in this order
- 01Enable VSM stats and confirm that Pages exceeds Max Pages.
- 02Reproduce the peak view and scalability level on the lowest-memory target.
- 03Reduce virtual-shadow resolution or the number of VSM-casting lights.
- 04Increase Max Physical Pages only when the added GPU memory fits the platform budget.
Views and commands
Shader print
r.ShaderPrintEnable 1Enables the on-screen output required by VSM statistics.
VSM page stats
r.Shadow.Virtual.ShowStats 2Shows current page use and the physical-page maximum.
Physical page pool
r.Shadow.Virtual.MaxPhysicalPagesPrints or sets the maximum physical pages available to Virtual Shadow Maps.