Minecraft version: 1.20.1-forge (also tested 1.20.1-fabric)

Mod version: 0.5.12

GPU: tested with Intel(R) Iris(R) Xe Graphics and NVIDIA GeForce RTX 4060 Laptop GPU

This issue has two somehow different aspects.

Frustum Culling

1. Enter a world, fly up to look down upon the terrain.
2. Turn around and wait for the chunks to load entirely.
3. Try to turn around quickly.
   ❎ You may notice that some chunks that has just come into view remain unrendered for a while (despite having already been fully loaded). The issue is more prominent with a low FPS limit.

▲ In this case, I am turning my head right rapidly.

This issue only exists when Async Rebuild Chunk is enabled.

Occlusion Culling

1. Enter a world and find a sparse forest (or build up a pillar on the plains).
2. Turn around and wait for chunks to load entirely.
3. Hide behind a tree with your eyes facing the trunk.
4. Walk left or right so that you are no longer hiding behind the tree.
   ❎ Note that some formerly occluded chunks that has just become visible remain unrendered for a while (despite having already been fully loaded). The issue is more prominent with a low FPS limit.

▲ In this case, I am walking right.

The issue exists regardless of the Async Rebuild Chunk toggle. It seems that the only way to avoid it is to turn off chunk culling.