Goal
Fog gives a level its atmosphere and its sense of scale: the far field fading into the sky colour, mist pooling in a valley or along a street at dawn, a torch beam cutting through a damp cave, dust hanging in the light of a window. The engine has no fog of any kind today, so every scene reads as clear air to the horizon.
The goal is fog at three levels of cost. Distance and height fog, analytic and per pixel in the light pass from depth: colour, density, start and end, a height falloff, saved with the scene, applied consistently to opaque geometry, transparent objects and Gaussian splats. Volumetric fog, a view-aligned froxel grid that takes density from the scene and in-scattering from its lights and shadows, with temporal reuse and half resolution on visionOS, which gives god rays and lit mist. Local fog volumes placed as entities so a designer can fill one room or one corridor. On visionOS fog applies in full immersion only; over passthrough the real room sets the air. Fog is atmospheric and computed in the lighting and post passes; smoke, which is emitted and drifts, belongs to the particle system (issue #1237).
Status
| Step |
Plan |
Status |
| Requirements |
Which of the three the game needs first; behaviour on visionOS (no fog over passthrough in mixed immersion, full fog in full immersion); interaction with the sky and the tone map |
Not started |
| Distance and height fog |
Analytic fog in the light pass from depth: colour, density, start and end, height falloff; per-scene settings saved with the scene; transparent objects and Gaussian splats fogged consistently |
Not started |
| Volumetric fog |
Froxel grid (view-aligned 3D texture) with density injection, in-scattering from the scene lights and shadows, temporal reuse; half resolution on visionOS with foveation |
Not started |
| Local volumes |
Fog volumes placed as entities (a box or sphere of denser fog) authored in the editor |
Not started |
| Editor |
Fog settings in the environment panel with live preview |
Not started |
| Sample |
A misty street on one of the demos with the performance counters attached |
Not started |
Next steps
- Distance and height fog first: small, and most scenes want it.
- Volumetric fog after the performance work on visionOS, since it is a full-screen cost at two eyes.
Goal
Fog gives a level its atmosphere and its sense of scale: the far field fading into the sky colour, mist pooling in a valley or along a street at dawn, a torch beam cutting through a damp cave, dust hanging in the light of a window. The engine has no fog of any kind today, so every scene reads as clear air to the horizon.
The goal is fog at three levels of cost. Distance and height fog, analytic and per pixel in the light pass from depth: colour, density, start and end, a height falloff, saved with the scene, applied consistently to opaque geometry, transparent objects and Gaussian splats. Volumetric fog, a view-aligned froxel grid that takes density from the scene and in-scattering from its lights and shadows, with temporal reuse and half resolution on visionOS, which gives god rays and lit mist. Local fog volumes placed as entities so a designer can fill one room or one corridor. On visionOS fog applies in full immersion only; over passthrough the real room sets the air. Fog is atmospheric and computed in the lighting and post passes; smoke, which is emitted and drifts, belongs to the particle system (issue #1237).
Status
Next steps