First Grand Theft Auto 4 RTX Remix Update Improves Lighting, Weather, And Stability

The first public update for Grand Theft Auto 4 RTX has been released, delivering a broad set of visual fixes and feature additions to the RTX Remix path tracing mod. Developed by modder xoxor4d, the update focuses on correcting lighting behavior, improving material rendering, and expanding environmental effects, with rain now fully implemented across Liberty City.

Grand Theft Auto 4 RTX enables real-time path tracing through NVIDIA’s RTX Remix framework, replacing the original lighting model with physically based illumination. The mod targets players with high-end GPUs who want to revisit GTA 4 with modern rendering techniques. Since its initial release, the project has drawn attention for how completely it transforms the game’s lighting, reflections, and surface response without altering core gameplay.

This first update addresses a range of issues reported by early users. One of the most visible fixes resolves artifacts that appeared in front of glowing surfaces, a problem tied to alpha blending and emissive materials. Several emissive objects were also displaying incorrect brightness or missing color data, causing white surfaces to appear washed out. These elements now render with proper vertex colors and more consistent intensity, supported by a tweaked visualSettings.dat included with the patch.

Vehicle rendering has received targeted improvements. Rear lights that previously suffered from blending errors have been corrected, while vehicle windows are now transparent by default, even without custom Remix overrides. Reflections on that glass are still limited, but the update brings the appearance closer to the original intent. Police cars also benefit from a long-requested fix: their V-shaped sirens now spawn actual spinning lights instead of static emissive textures, though siren color tuning remains a work in progress.

Interior behavior has also been refined. A new anti-culling option prevents certain indoor objects from disappearing unexpectedly. One example cited by the developer is Niko Bellic’s bedside lamp, which will now remain visible instead of vanishing due to aggressive culling logic. Several glass materials in locations such as cafes and showrooms have been updated to behave as translucent surfaces rather than opaque geometry.

The weather is the most substantial addition. Rain is now implemented using a new particle system attached to a map marker that follows the player. The system supports four variants: light and heavy rain for both day and night. Raindrops now appear on character models and vehicles, and decals correctly react to wet conditions. The update also resolves an issue where characters could appear wet indoors during storms, with new adjustable settings added to control rain behavior.

Under the hood, the installer has been updated to request administrator permissions automatically, removing the need for manual elevation. The Remix runtime has also been updated to the latest commit with GTA IV–specific changes applied. A new work-in-progress tab has been added to the F4 menu to expose experimental features as development continues.

Below is the complete changelog for the first Grand Theft Auto 4 RTX Remix update, reproduced from the release notes.

• Emissive surfaces now support UV animations
• Fixed an issue with alpha-blended emissive surfaces being too transparent
• Fixed effect artifacts in front of emissive surfaces (#11)
• Now shipping a tweaked visualSettings.dat to adjust some emissive intensities
• Added raindrops to character meshes and fixed characters getting wet inside, with adjustable game settings (#12)
• Added raindrops to vehicles, with adjustable game settings (#13)
• Fixed decals not getting wet when it rains
• The V-shaped sirens of police cars now spawn actual, spinning lights (siren color still work in progress)
• Added a new anti-cull option for interior objects; Nico’s bed lamp should no longer get culled
• Fixed texture issues on vehicle rear lights caused by stochastic alpha blending
• Fixed several white emissive surfaces that were missing vertex colors
• Vehicle glass is now transparent by default even without a translucent Remix override, though reflections are limited
• Added a work-in-progress tab to the F4 menu
• Installer now requests UAC, removing the need to start manually with admin permissions
• Updated the Remix runtime to the latest commit with GTA IV changes applied
• Fixed translucent funfair stairs (#22)
• Made several glass textures translucent, including Grotti and cafe assets
• Added rain via a Remix particle system attached to a map marker that follows the player (#23)
• Four rain variants: heavy and light rain for day and night
• Collision detection for rain remains work in progress and may trigger rain where it should not

The update is available through the project’s GitHub repository, with further refinements expected as development continues.