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Chimera fixes numerous bugs present in the original Halo PC release, ranging from minor annoyances to game-breaking issues. All bug fixes are always enabled to provide the best experience. Many bugs in Halo PC are caused by poor frame rate handling:

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Camera Shake Fix

Fixes camera shaking not working correctly at high frame rates.
Problem: Camera shake effects (explosions, impacts) don’t work properly above 30 FPS.Solution: Frame-rate independent camera shake calculations.

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Checkpoint Fix

Prevents checkpoints from timing out too quickly at high frame rates. 
// Checkpoints were timing out based on frame count, not actual time
// Chimera fixes this to use real time
Impact: You won’t lose checkpoint progress in campaign at high FPS.

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Auto Center Fix

Fixes vehicle auto-centering being frame rate dependent.
Without this fix: Vehicles are difficult to control at high frame rates due to aggressive auto-centering.With this fix: Natural vehicle handling regardless of FPS.
Location: src/chimera/fix/auto_center.cpp

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Contrail Fix

Fixes contrails (rocket trails, etc.) being bugged at high frame rates.

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Motion Sensor Fix

Corrects motion sensor fade animation at >30 FPS.

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Name Fade Fix

Player names now fade in/out correctly at high frame rates when looking at other players.

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Scoreboard Fade Fix

Scoreboard fades in/out properly at high frame rates. Configuration: Fade timing can be customized in chimera.ini: 
[scoreboard]
fade_time=0.5  ; 0 = instant, higher = slower

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Weapon Swap Ticks Fix

Weapons are now picked up with correct timing when holding the action key.
Previously, weapon pickup timing was frame-rate dependent, making it inconsistent at different FPS.

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Gameplay Fixes

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Descope Fix

The most important multiplayer fix - proper descoping behavior.
In Halo PC multiplayer, descoping (automatic zoom-out when taking damage) is broken:
  • Client only descopes when taking damage on the client instance
  • Does NOT descope when actually taking damage on the server
  • Results in staying zoomed while being shot (unfair advantage)
Chimera changes descoping to trigger when you lose health or shield:
// Descope when actual damage is taken (server-side)
if(health_decreased || shield_decreased) {
    descope_player();
}
This matches Xbox behavior and makes sniping fair.
Impact: Essential for competitive multiplayer balance.

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Timer Offset Fix

Fixes a bug where equipment spawns at incorrect timing. 
// Halo PC bug: equipment spawns floor(8.1n) ticks
// where n = netgame equipment index
// Chimera corrects this calculation
Location: src/chimera/fix/timer_offset.cpp

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Multi-team Vehicle Fix

Prevents desync when using multi-team vehicles with chimera_allow_all_passengers.
Servers with this command enabled allow anyone to enter any vehicle, not just teammates.

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Visual Rendering Fixes

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FOV Fix

Fixes FOV getting narrower at higher vertical resolutions.
Gearbox Bug: Increasing vertical resolution narrows FOV, even on the same aspect ratio.Chimera Fix: FOV stays consistent between vertical resolutions.
Location: src/chimera/fix/fov_fix.hpp
This does NOT fix low FOV at widescreen aspect ratios - use the chimera_fov command for that.

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Model LOD Fix

Prevents the infamous “4K headless chief” glitch. The Problem:
  • Game uses vertical resolution to determine model detail level
  • At 4K resolution, it shows the highest LOD inappropriately
  • Causes missing heads in cutscenes (The Pillar of Autumn level)
The Solution: 
// Scale by 480p instead of actual resolution
// Prevents inappropriate LOD selection

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Sun Fix (Lens Flare)

Lens flares now scale properly with resolution.
  • Before: Set number of pixels regardless of resolution
  • After: Scales by 768p for consistency

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Zoom Blur Fix

Improves zoom blur quality and scaling. Improvements:
  • Blur radius scales by 480p (not hardcoded pixels)
  • Increased effect resolution
  • Better quality at high resolutions
Disable it: Use chimera_block_zoom_blur if you prefer no blur.

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Z-fighting Fix

Reduces Z-fighting (flickering surfaces) at far distances.
Problem: Floating point precision loss causes Z-fighting as you get further from map center.Solution: Chimera reduces decal Z-fighting with level geometry.

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Multitexture Overlay Fix

Fixes blending issues with multitexture overlays. Example: Sniper rifle scope angle ticks now blend correctly. Location: src/chimera/fix/multitexture_overlay_fix.hpp

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Shader and Graphics Fixes

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Shader Fixes

Restores Xbox-accurate rendering by fixing Gearbox shader regressions. Fixed shader types:
  • shader_transparent_generic - Missing in Halo PC, restored by Chimera
  • Environmental bump mapping
  • Specular lighting
  • Fog rendering
Location: src/chimera/rasterizer/shader_transparent_generic.cpp

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Fog Fix

Fog in maps like Assault on the Control Room now works as intended. Impact: Proper atmospheric effects in campaign levels.

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Model Detail Fix

The “detail after reflection” flag in model shaders now works correctly.

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HUD Numbers Fix

HUD numbers no longer drawn oversized if modified to be higher resolution.

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NVIDIA Camo Fix (Trial Only)

Fixes NVIDIA GPUs using alpha-blended camo instead of liquid shader in Halo Trial.
This fix only applies to Halo Trial, as retail/CE don’t have this bug.

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Loading and Performance Fixes

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Fast Loading

Significantly improves startup time for large map folders.
Halo Custom Edition CRC32s every map on startup:
  • Small maps folder: Minor delay
  • Large maps folder: Minutes of loading time
Chimera CRC32s maps when you load them, not at startup:
// CRC32 on map load, not game startup
// Maintains server validation
// Eliminates startup delay
This is a true fix - not a cache that bypasses validation.
Location: src/chimera/map_loading/fast_load.cpp

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Fast Server Listing

Speeds up querying the master server for game list.

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128 MiB Map Leak Fix

Prevents file descriptor leaks with large maps. The Bug: 
// If map > 128 MiB:
// - Opens file multiple times
// - Only closes it once
// - File descriptors leak
// - Eventually runs out of file handles
The Fix: Removes the problematic file size check. Location: src/chimera/fix/leak_descriptors.cpp

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Extended Description Fix

Fixes the “About” button in profile settings not displaying the correct bitmap.

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Reduced DRM

Removes CD key check for local hosting.
Original behavior: Can’t join your own locally hosted server with same CD key.Chimera behavior: Can host and join yourself for testing.
This does NOT crack the game - you still need a valid Halo installation and 1.10 update.

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Removed Annoyances

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Removed Update Check

Disables the outdated update check when clicking “INTERNET” in menus.

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Removed Watson

Removes the Watson crash reporter that tries to contact a dead server. Why: Watson hasn’t worked in years and just adds delay after crashes. Many additional fixes can be toggled via commands:

Block All Bullshit

Disable annoying UI elements at once

Visual Commands

Toggle various visual elements

Widescreen Fix

Fix HUD scaling for widescreen

Devmode

Enable devmode without restrictions

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Technical Reference

Bug fix implementations are located in: 
src/chimera/fix/
├── auto_center.cpp
├── camera_shake_fix.cpp
├── checkpoint_fix.cpp
├── contrail_fix.cpp
├── descope_fix.cpp
├── fov_fix.cpp
├── interpolate/
├── leak_descriptors.cpp
├── model_detail.cpp
├── motion_sensor_fix.cpp
├── multitexture_overlay_fix.cpp
├── name_fade.cpp
├── scoreboard_fade_fix.cpp
├── timer_offset.cpp
├── weapon_swap_ticks.cpp
└── z_fighting.cpp

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