CLab

> Bringing **Hardware Occlusion Culling (HOC)** to Minecraft entity rendering optimization. CLab is a client-side rendering optimization mod. It leverages GPU OpenGL occlusion queries to determine entity visibility directly, eliminating the approximation errors and side effects inherent to traditional CPU-side pathtracing.  ## Core Features - **Hardware Occlusion Culling (HOC)** Uses GPU queries to test entity bounding boxes against the depth buffer, measuring real occlusion against actually rendered terrain rather than CPU-side approximations of the world model. - **Zero False-Positive Culling** Based on ground-truth depth buffer testing. An entity is never hidden if even a single pixel is visible. No whitelist needed, no per-mod patches required. - **Render-Layer Only, Zero Intrusion** Only decides whether to invoke the entity render method. Does not interfere with client-side ticks, animation states, position interpolation, or any logic. Trains, vehicles, and contraptions behave normally. - **Built-in Leaf Face Culling** Automatically culls leaf faces occluded by adjacent leaves, reducing terrain rendering overhead. - **Zero-Config, Works Out of the Box** No entity whitelist, no distance threshold, no tick-culling toggle. Install and play. ## Technical Overview CLab uses **Hardware Occlusion Culling**: 1. During entity rendering, submit the entity bounding box to the GPU as an occlusion query (OpenGL Query). 2. The GPU compares the bounding box against the already-rendered terrain depth buffer at the hardware level. 3. Read the previous frame's query result: if no pixels passed the depth test, skip rendering this entity. This creates a fundamental difference: | Aspect | CPU Pathtracing | CLab HOC | |--------|---------------|----------| | Occlusion basis | Simplified assumptions about world model | Actual GPU-rendered depth buffer | | False positives (hiding visible entities) | Common (near non-solid blocks) | Extremely unlikely | | Entity tick/animation | Often frozen or skipped | Completely unaffected | | CPU overhead | Continuous background traversal | Render thread submits AABB only; GPU handles the rest asynchronously | | Configuration required | Whitelists, distance limits, thresholds as compensatory mechanisms | None required | ## ⚠️ Important Compatibility Notes * **Hardware Requirement:** CLab requires a dedicated graphics card with **OpenGL 3.3 or higher**. Most modern GPUs meet this requirement, but certain older integrated graphics or outdated drivers may not. * **Do NOT use with other entity culling mods:** CLab should **not** be installed alongside **EntityCulling** or any other mod that modifies entity/block entity visibility. While these mods use different techniques, they all ultimately override the same visibility decisions. Running more than one will not improve performance — instead, they may conflict and cancel out each other's optimizations, resulting in wasted resources and potential visual inconsistencies. For the best results, keep only CLab active. ### Compatibility & Future Optimizations The current approach was chosen to maintain compatibility with older devices and macOS. A more advanced technique is available, but it would introduce compatibility problems on those systems. Development and testing are currently done on a Mac, which limits how far I can improve things today. I plan to transition to a machine with OpenGL 4.6 support soon, after which I’ll introduce a system that automatically selects the optimal method during loading.