Streaming load priority (smaller = more urgent): camera distance, pulled forward for
tiles far over the error budget so the cache resolves the most visible error first.
Bounded to (0, distance], so a near tile is never starved by a far high-error one.
Streaming load priority (smaller = more urgent): camera distance, pulled forward for tiles far over the error budget so the cache resolves the most visible error first. Bounded to (0, distance], so a near tile is never starved by a far high-error one.