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L4D2MC 2.0.12 ⚡
Download L4D2MC-Companion.exe, select RU / EN, open Setup and use Update and install on both PCs with Minecraft and L4D2 closed. Launch the Minecraft profile through your normal launcher, then use Play. The host creates a co-op invitation; the friend enters their own L4D2 nickname. Installation guide.
Choose the guest renderer's workload
Play now offers three Minecraft performance presets, independently on each PC:
| Preset | Minecraft dimensions | Guest frame cap |
|---|---|---|
| Quality — existing default | 100% of Source | Uncapped (260 sentinel) |
| Balanced | 75% | 90 FPS |
| Low-end PC | 50% | 60 FPS |
L4D2 keeps its resolution. At 2560×1440, Low renders Minecraft at 1280×720: 75% fewer guest pixels and frame payload bytes. This is a workload reduction, not a measured FPS improvement. Lower presets soften Minecraft, including its UI, and can increase frame age. Low also skips cosmetic bloom, contact shadows and edge smoothing while retaining lighting and depth checks. Performance notes.
Less repeated work
- Empty or occluded Minecraft pixels skip unnecessary lighting and effect samples. Reprojection retains all 24 search steps and 12 refinements, with invariant arithmetic moved out of the loops.
- Collision scanning skips empty chunk sections. Complete stationary snapshots can be reused briefly; edits, movement, missing chunks and scene changes invalidate the cache. Dynamic shapes and block entities prevent reuse.
- Loaded projectile and mob indexes replace repeated whole-world scans. Stable nearest-64 selection avoids sorting every reported mob.
- Source navigation caches static area corners while keeping blockage and geometry traces live. Unchanged Source JSON has bounded parse reuse without extending frozen-pose freshness.
Checks and limits
158 Python tests, Java/Fabric build and policy checks, native checks, 11 Source suites, and the RU/EN companion build/tests passed. Games were not launched for this release at the author's request. Runtime shader compilation, FPS/frametime measurements and live collision/visual checks are pending.
This is a normal release of the EXE and source package. Co-op remains experimental. Intermittent network interruptions, fast-motion reprojection holes and some grass/bottle/late-material render order issues are still possible. This release does not claim to fix every rendering issue.
Windows 10/11, .NET Framework 4.8, Steam L4D2, Minecraft Java 26.3 / Java 25, official L4D2 Authoring Tools. The EXE is unsigned. Downloads exclude game-derived JAR/HUD, worlds, private configs, credentials and toolchains. Both assets have SHA-256 files.