Includes:

• Major rework of core rendering internals, for sake of v1.13 - performance improvement for all versions
• New fluid rendering model: flowing water/lava rendered to match in-game models, 1.13 immersed blocks rendered properly at surface (partially submerged blocks like slabs, stairs, etc)
• Fix for white stained glass in 1.13.x
• Avoid warnings for 1.13.1 blocks in 1.13

Fluid rendering change applies to all versions, not just 1.13.x