Ray Traced Fog & Reflections in Voxel Space

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In the world of computer graphics, creating realistic and immersive environments is a constant pursuit. Two essential elements that contribute to the overall visual quality of a game are fog and reflections. In this blog post, we will explore how fog and reflections are implemented using ray tracing techniques in the voxel space of the game Meor, a smooth voxel game that primarily utilizes the GPU for its rendering.

Ray Traced Fog

Fog is a visual effect that adds depth and atmosphere to a scene. In Meor, fog is implemented by utilizing ray tracing to calculate the voxel global illumination cascading clipmap grids. The process starts from the camera’s near plane and extends in the direction the camera is facing. By traversing these grids, the game can determine the fog density at various points in the scene.

To avoid banding artifacts, blue noise is introduced during the tracing steps. Blue noise is a type of noise that exhibits desirable properties, such as a more uniform distribution and reduced perceptual artifacts. By applying blue noise to the ray tracing process, the visual quality of the fog is significantly improved.

Additionally, light accumulation is taken into account during the ray tracing steps. This means that the fog’s appearance is affected by the lights present in the scene, resulting in more realistic and dynamic fog effects.

Ray Traced Reflections

Reflections play a crucial role in creating realistic and visually appealing environments. In Meor, reflections are achieved through ray tracing techniques applied to the voxel grids. The process begins by determining the world position using the depth texture (Z buffer) and the surface normal using the normal texture.

To ensure accuracy and smoothness, motion vectors are utilized to reproject the previous buffer. This technique compensates for any movement in the scene, ensuring that the reflections stay aligned with the dynamic objects in the game.

By tracing rays in the voxel space, Meor is able to accurately calculate reflections, taking into account the complex geometry and lighting present in the environment. This enhances the overall visual fidelity and immersion, making the game world feel more realistic and engaging.

Performance Considerations

While achieving high-quality fog and reflections is essential, performance considerations are also crucial, especially in real-time applications such as gaming. To optimize performance, certain measures are taken in Meor.

Both the fog and reflections are rendered at reduced screen buffer resolutions. This reduction in resolution helps improve performance by reducing the computational load on the GPU. However, to compensate for the lower resolutions, screen-space blue noise is added. This technique introduces carefully crafted noise patterns that help mask the upscaling artifacts, resulting in visually pleasing and higher-quality fog and reflections despite the decreased resolution.

By finding the right balance between visual quality and performance optimization, Meor manages to deliver stunning ray traced fog and reflections without sacrificing the smooth voxel experience it offers.


In this blog post, we explored the implementation of ray traced fog and reflections in the voxel space of Meor. By utilizing ray tracing techniques, the game achieves realistic and visually appealing fog effects, adding depth and atmosphere to the scenes. The reflections, on the other hand, enhance the overall visual fidelity and immersion by accurately rendering the surrounding environment.

With performance considerations in mind, Meor optimizes the rendering process by decreasing the screen buffer resolutions of fog and reflections. This optimization is supplemented by the addition of screen-space blue noise to compensate for the lower resolutions, ensuring that the visual quality remains high.

By combining cutting-edge ray tracing techniques, optimized performance, and a smooth voxel experience, Meor creates a visually stunning and immersive game world that captivates players.

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