Console Variables for Volumetric Fog

Open 3D Engine (O3DE), the successor to Lumberyard, is now available in Developer Preview. Download O3DE or visit the AWS Game Tech blog to learn more.

You can specify the following console variables (CVARs) to enable volumetric fog effects. For more information, see Using the Console Window.

Console Variable	Description	Values
e_VolumetricFog	Toggles the Volumetric Fog component on or off.	0 = Off 1 = On
r_VolumetricFogTexScale	Sets the width and height of the internal volume texture. Screen resolution divided by this factor is applied to the width and height of the fog volume.	The minimum value should be 2.
r_VolumetricFogTexDepth	Sets the depth for the internal volume texture.	This value should be multiples of 4, but less than 252.
r_VolumetricFogReprojectionBlendFactor	Sets the blending factor of the temporal reprojection filter. Higher values cause less flicker, but more ghosting.	0 = Turn off temporal reprojection.
r_VolumetricFogReprojectionMode	Sets the mode of ghost reduction for the temporal re-projection filter.	0 = Conservative mode. Ghost artifacts can appear when a light moves, but there is less flicker than in the advanced mode. 1 = Advanced mode. This mode has fewer ghost artifacts but slightly more flicker than the conservative mode.
r_VolumetricFogSample	Sets the number of sample points.	0 = 1 sample point in a voxel. 1 = 2 sample points in a voxel. 2 = 4 sample points in a voxel.
r_VolumetricFogShadow	Sets the shadow sample count for each sample point.	0 = 1 shadow sample per sample point. 1 = 2 shadow samples per sample point. 2 = 3 shadow samples per sample point. 3 = 4 shadow samples per sample point.
r_VolumetricFogDownscaledSunShadow	Replaces sun shadow maps with downscaled shadow maps or static shadow maps, if possible. This reduces the volumetric fog flicker for sun shadow.	0 = Disabled. 1 = Replace first and second cascades with downscaled shadow maps. Others are replaced with a static shadow map, if possible. 2 = Replace first, second, and third cascades with downscaled shadow maps. Others are replaced with a static shadow map, if possible.
r_VolumetricFogDownscaledSunShadowRatio	Sets the downscale ratio for sun shadow maps.	0 = 1/4 downscaled sun shadow maps. 1 = 1/8 downscaled sun shadow maps. 2 = 1/16 downscaled sun shadow maps.
r_VolumetricFogMinimumLightBulbSize	Sets the minimum size threshold for light attenuation bulb size for voxel-based volumetric fog. Note Small bulb sizes can cause light flicker.	Specify a value between 0 to 2. Default value: 0.4