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Make sure you read up on the Time of Day documentation to discover how to tweak environment fog for your level.

Fog (Obsolete)

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Note
titleObsolete
Due to major changes to the Volumetric fog system, this entity is now obsolete. Use Fog Volumes instead and/or modify Fog values via the Time of Day tool.

The Fog entity is used to overwrite the fog effect in specific areas. In indoor areas a subtle fog effect can be added to simulate a dusty area.

To use, create an area shape and link the shape to the Fog Entity. When in game mode, you can walk into the area and see how the fog gets different inside. Outside Game mode the fog is not visible.

Property

Description

AtmosphereHeightModifier

Defines the height of the density above sea level. The higher the atmosphere the less visible the effect of horizontal fog layers.

FadeTime

Sets up the time in which the fog takes to fade in.

GlobalDenstiyModifier

Specifies the density of the fog.

Fog Volumes

FogVolumes exhibit the same properties of global volumetric fog, with the added benefit of locality. Currently supported volume types are boxes and ellipsoids (including spheres as a special case).

The benefit of using a FogVolume is that it is possible to define fog volumes that can be non-uniformly scaled along their major axes, rotated, and have an arbitrary fall-off direction (unlike global volumetric fog which defines the world space up-vector as its fall off direction).

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A HMMWV inside two fog volumes - One large (brown) and one small radius (orange).

Fog volumes are placed as entities . To place one open the RollupBar, select Entity, Render and then FogVolume in the tree view belowvia RollupBar -> Entity -> Render -> FogVolume. Drag the entity into the render view perspective viewport to place it. You should be see a white, spherical fog volume.

Translation and Rotation of a fog volume entity is performed via the move and rotate edit mode just like for any other object. Non-uniform scaling will distort the entity and produce incorrect rendering results.

Property

Parameter

Description

Active

Select/deselect this box to enable or disable this fog volume entityIf true, fog volume will be enabled.

Color

Set Specify the RGB diffuse color of the fog colorvolume.

DensityOffset 

Offset fog density, used in conjunction with the GlobalDensity parameter.

FallOffDirLati

This value controls Controls the latitude of the world space fall off direction of the fog.
  A value of 90° lets the fall off direction point upwards in world space (respectively, -90° points downwards).
All values in-between create a direction along the specified longitude.
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longitude 0°, latitude 90° / longitude 330°, latitude 45°

FallOffDirLong

This value controls Controls the longitude of the world space fall off direction of the fog. 0° represents East, rotation is counter-clockwise.

FallOffScale

This value scales Scales the density distribution along the fall off direction. Higher values will make the fog fall off more rapidly and generate thicker fog layers along the negative fall off direction.
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Scale set to 0.5 and 2.0 (from left to right)

FallOffShift

This value controls Controls how much to shift the fog density distribution along the fall off direction in world units (m).
Positive values will move thicker fog layers along the fall off direction into the fog volume. Negative values will move thick layers along the negative fall off direction out of the fog volume.
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Shift set to -1.0 and 21.0 (from left to right)

GlobalDensity

This value controls Controls the global density of the fog. The higher the value the more dense the fog and the less you'll be able to see objects behind or inside the fog volume.

HDRDynamic

HDR brightness multiplier for the fog colorSpecifies how much brighter than the default 255,255,255 white the fog is.

NearCutoff

Stop rendering the object, depending on camera distance to object.

SoftEdges

This value specifies Specifies a factor that is used to soften the edges of the fog volume when viewed from outside.
A value of 0.0 produces hard edges. Increasing this value up to 1.0 will gradually soften the edges. This property currently has no effect on Box type Fog Volumes.
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UseGlobalFogColor

During rendering the Color If true, the color property is ignored. Instead, the current global fog color is used. Please refer to the Volumetric Fog page for further information.

VolumeType

Specifies the volume type. The following types are currently supported: 0 - Ellipsoid, 1 - Cube.

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Type 0 - Ellipsoid (left), Type 1 - Cube (right)

Size

The height/width/depth of the fog volume in world units (m). Non-uniform scaling is possible so height, width and depth don't have to be the same.

Tips and Troubleshooting

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titleSpecial Tips
  • Fog volumes should not overlap. In some situations (i.e. clever placement of volumes) it might work but in general it won't. Fog volumes are internally treated and processed like alpha-transparent objects so the general sorting issue of these apply here as well. However, inclusion should work as it is guaranteed that smaller ones never overlap with bigger ones.
  • Even though alpha-transparent objects behind fog volumes will be fogged per-pixel, this is not the case for when they are inside fog volumes.
  • Fog densities cannot change in dynamic, non-uniform way (smoke-like). A particle effect with soft particle blending enabled is much better suited for that purpose.

Debugging

Include Page
cryautogen:eFog
cryautogen:eFog
Include Page
cryautogen:eFogVolumes
cryautogen:eFogVolumes

Troubleshooting

Q: Shadow maps inside fog volumes do not work, what's wrong?

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