SmoothGL V5 — Performance & Stability Update (Modrinth Changelog)

🔧 Fixes & Optimizations

1. FogRenderer crash fix

• Updated setupFog mixin injection signature for Minecraft 1.21.4
• Disabled vanilla fog by forcing extremely large fog distances (999999.0f)

2. Thread-safety improvements — PipelineTrace

• Replaced HashMap with ConcurrentHashMap for chunkStates

• Replaced counters with AtomicLong

• Added cleanup of chunkStates entries after RENDER_SUBMITTED

  • Prevents unbounded memory growth
  • Reduces GC spikes and long pauses

3. Hot path optimization — Double-Checked Locking

Implemented volatile + DCL singleton access for:

• GeometryKernel
• PipelineTrace
• ParticleCullingSystem
• SmoothGLDecisionEngine
• StabilityLayer
• FrameBudgetController
• SmoothGLController
• SmoothGLApi
• RenderImpactProfiler

Additional changes:

• Removed unnecessary synchronized methods from hot paths

4. Removed expensive logic from render hot paths

• Removed per-face distance-based leaf LOD checks from AbstractBlockRenderContext.isFaceCulled()

• Eliminated repeated:

  • getInstance() calls
  • BlockPos allocations
  • instanceof checks per face

• Sodium occlusion cache now handles inter-leaf culling more efficiently

5. Cached renderer references — BlockRenderer

Added cached fields:

• cachedGeom
• cachedCuller
• cachedLeafCullDistSq

References are now resolved once during prepare() instead of per-block rendering.

6. Debug overhead disabled

• debugMode = false by default across SmoothGL systems
• Removed System.out.println calls from rendering hot paths
• Disabled unused PipelineTrace.enable() initialization

Result:

• Lower CPU overhead
• Reduced console spam
• Better frame consistency

7. More aggressive performance tuning

GeometryKernel

• leafCullDistance: 24.0f (was 32)
• simplificationDistance: 48.0f (was 64)
• Enabled alphaOverdrawReduction

ParticleCullingSystem

Enabled:

• Distance culling
• Frustum culling

Particle thresholds:

• Smoke: 32
• Rain: 48
• Default: 24

8. Particle culling restored

• Restored missing logic in SingleQuadParticleMixin.renderRotatedQuad()
• Particle culling works correctly again

9. Removed atomic operations from hot paths

• Removed addAlphaOverdrawReduced(1) from leaf culling in BlockRenderer.renderModel()
• Reduces synchronization overhead during chunk rendering

10. Leaf rendering fixes

Fixed issue where leaves would not appear until a neighboring block was updated.

Changes:

• Added explicit leaf-to-leaf checks in AbstractBlockRenderContext.isFaceCulled()
• Leaves now always render faces between each other
• Bypasses problematic occlusion behavior

11. Updated mod metadata

• Updated fabric.mod.json
• Added detailed feature descriptions for Modrinth/launcher display

🚀 Overall Results

• Lower CPU overhead in chunk rendering
• Reduced memory pressure and GC spikes
• Improved thread safety
• Better particle rendering performance
• More stable rendering pipeline on Minecraft 1.21.4
• Faster and more consistent frame times