Reshade Ray Tracing Shader Rtgi 033 💫

The ReShade Ray Tracing Shader RTGI 0.33 update, released in August 2022, introduced a significant technological leap for the popular post-processing tool by adding motion vectors support. Developed by Pascal Gilcher (also known as Marty McFly), the RTGI (Ray Traced Global Illumination) shader allows players to simulate advanced lighting effects like bounce lighting and realistic shadows in older games that lack native ray tracing support. Key Features of RTGI 0.33

The 0.33 version was a major milestone for the Marty's Mods collection. Its primary advancement was the integration of motion vectors, which dramatically improved temporal stability.

Realistic Bounce Lighting: Simulates how light physically interacts with objects, allowing colors from the floor or walls to "bounce" and illuminate the rest of a scene.

Hardware Independence: Unlike native RTX solutions, this shader operates on depth data alone, making it compatible with non-RTX video cards.

Motion Vector Support: Introduced in version 0.33, this feature helps the shader track object movement, reducing the "ghosting" or flickering artifacts common in earlier post-process ray tracing attempts.

Customizable Parameters: Users can fine-tune "Ray Amount" and "Ray Step Amount" to balance visual fidelity with hardware performance. Performance and Setup

Implementing RTGI 0.33 is a demanding task for any GPU. It works by "ray marching" through the screen space depth buffer to approximate lighting, which is different from true hardware ray tracing that calculates data for the entire 3D scene. reshade ray tracing shader rtgi 033

Installation: The shader is typically available through Pascal Gilcher’s Patreon. Installation involves dragging the shader and texture files into the reshade-shaders folder of a game's directory.

Performance Cost: Activating full RTGI (Diffuse and Specular) can impact frame rates significantly, sometimes halving them depending on the game and hardware.

Technical Requirements: ReShade must have access to the game's depth buffer to function. This often requires disabling in-game anti-aliasing (MSAA) and sometimes using wrappers like DXVK to convert older DirectX versions to Vulkan for better compatibility. Why Use Version 0.33?

While newer versions like 0.51 have since been released with features like "Sky Color", version 0.33 remains a popular reference point in the community because it was the first to implement the robust motion vector system that bridged the gap between basic screen-space effects and more stable, modern lighting techniques.

This version is a legacy Martys Mods release (before the switch to the newer "qUINT" and "Pathtracing" frameworks). It is known for its performance efficiency and classic "bounce lighting" effect.

Step-by-Step Setup

Step 1: Install Base ReShade

• Download the latest ReShade setup tool from reshade.me.
• Run the installer. Select your game’s .exe file.
• Choose the rendering API (usually DirectX 10/11/12 for most modern games).
• When asked for effects, download the Standard effects (this gives you the framework).

Step 2: Acquiring RTGI 0.33

• Search for "Marty McFly RTGI 0.33" on reputable PC gaming modding sites (like Nexus Mods or GitHub Gists).
• Look for the file named RTGI.fx and its associated RTGI texture folder.
• Note: Do not download from suspicious pop-up sites. The legitimate file hash is widely documented on the Reshade Forum.

Step 3: Manual File Injection

• Navigate to your game’s install folder where ReShade is installed.
• Open the reshade-shaders folder.
• Open the Shaders subfolder.
• Copy RTGI.fx into this folder.
• Open the Textures subfolder.
• Copy the RTGI texture folder (often containing RTGI_BlueNoise.png) into this folder.

Step 4: Activation

• Launch your game.
• Press the Home key (default) to open the ReShade overlay.
• Click "Reload" (or press the reload button at the bottom).
• Scroll through the effect list and check the box next to RTGI.

Game Compatibility: Where RTGI 0.33 Shines

Because it is screen-space, RTGI 0.33 works best in third-person and first-person games with slow-to-moderate camera movement.

Excellent (Near-native look):

• Skyrim / Fallout 4 (Oldrim ENB users often combine this with ENB Light).
• GTA V / Red Dead Redemption 2
• Mass Effect Legendary Edition
• Dead Space Remake (Combine with native lighting for insane depth).

Good but noisy:

• Cyberpunk 2077 (The native Path Tracing is better, but 0.33 works on older GPUs).
• Call of Duty (Campaign).

Poor (Don't Bother):

• Fast-paced competitive shooters (CS2 / Valorant) – The latency and ghosting hurt reaction times.
• 2D pixel art games – The ray tracing logic breaks without a proper depth buffer.

Step 1: Install Base ReShade

1. Download the latest ReShade from reshade.me.
2. Run ReShade_Setup.exe.
3. Click "Select game" and browse to your game's executable (e.g., Cyberpunk2077.exe, SkyrimSE.exe, Witcher3.exe).
4. Select the Rendering API your game uses:
   • Most modern games: DirectX 10/11/12
   • Older games: DirectX 9
   • ID Tech games: Vulkan or OpenGL
5. When asked to select effect packages: Uncheck everything. You will manually add RTGI.
6. Click Install. This creates the ReShade DLL and the ReShade.ini file.

Artifacts and troubleshooting

• Flickering/ghosting: Lower temporal blend factor, enable motion vectors/reprojection, or increase denoiser strength.
• Missing GI from off-screen lights: Expected—RTGI is screen-space; use additional light passes or engine-side GI if needed.
• Haloing around edges: Adjust depth bias or increase sample count; ensure depth buffer is accurate.
• Excessive blur/softness: Reduce denoiser strength or temporal accumulation; increase sample count.
• Performance spikes: Reduce RPP, lower internal RTGI resolution, or reduce ray length.

Part 4: Fixing Common Issues with v0.33

4. Installation & Compatibility

Troubleshooting Common Issues

Issue 1: "Failed to compile RTGI.fx"

• Fix: Your ReShade is too new or too old. RTGI 0.33 works best with ReShade 4.9.1. Alternatively, update your GPU drivers.

Issue 2: The screen is pure white or black.

• Fix: The Depth Buffer is inverted. Go to ReShade settings -> "Depth" tab -> Check "Reverse Depth Buffer" or "Clear Depth Buffer before effects."

Issue 3: Light flickers wildly when I move the camera.

• Fix: This is screen-space artifact. Lower the "Ray Length" to 0.4 and increase "Reconstruction" to Ultra.

Issue 4: Massive FPS Drop (e.g., from 144 to 30).

• Fix: Lower "Quality" to Medium. Set "Resolution Scale" (if visible) to 0.5. Ensure no other heavy shaders (like MXAO) are running simultaneously.