Keep only parts of the volume that is covered by the fog volume mask (named according to Mask Volume) from the second input. This will have no effect when the second input is empty.

Negates the fog volume mask from the second input, if any.

Negates the clipping selection. Instead of sending things that match on the first output, send things that match as the second output.

Origin of the clipping plane.

Normal vector of the clipping plane.

Distance to translate the clipping plane along its normal.

Turns on displacement noise on the clipping plane, that will add cloud like features along the otherwise flat clipping plane.

The type of noise to generate. Different algorithms give noise with different characteristics.

Alligator

Produces a bumpy output, similar to alligator skin. While this node is not distorted by the fractal iterations, it is useful to create finer bumpy cloud details.

Perlin

Noise where the visual details are the same size. Wikipedia article

Perlin noise with Distortion set to -1 (left) and +1 (right):

Simplex

Noise similar to Perlin, but the noise lattice is on a tetrahedral mesh rather than a grid. This can avoid the grid patterns often visible in Perlin noise.

Simplex noise with Distortion set to -1 (left) and +1 (right):

Fast Simplex

This simplex noise function uses a different lattice structure and a cheaper accumulation method.

Simplex noise with Distortion set to -1 (left) and +1 (right):

The generated noise will be roughly from 0 to this value.

Uniform scale of elements in the noise.

Click the Per Component button for separate scales along each axis.

Turn on the Per Component button to scale the Element Size separately across each axis.

Offset within the evaluated noise field (added to each axis). If you have the general noise effect you want, but want to get a different set of values for a different look, try changing the offset.

You can animate the noise using an expression such as $T * 0.25 here. This is faster to compute than Animate Noise, but gives the visual effect of “panning” across the noise field.

Click the Per Component button for separate additional offsets along each axis.

Turn on the Per Component button to add the a separate offset along each axis.

By default the noise pattern is evaluated on the 2D clipping plane, therefore the displacement will have the characteristic of a grid displaced along it’s normals. In contrast, a value of 0 will evaluate the noise pattern in 3D space, which overall looks more neutral, however it is more likely to generate unwanted isolated fog islands around the clipping. Any value in-between will make the displacement blend between the two methods.

When turned on, a worley noise is combined with the noise pattern (specified by Noise Type) to give puffy cloud noise. Enabling this, will largely diminish the distortion effect (specified by Distortion).

Noise pattern with added worley noise:

Controls the amount of mixing between the noise pattern (specified by Noise Type) and the worley noise. A value of 0 means no worley noise is applied to the noise pattern.

Controls how fast the edges of the noise pattern turn to zero. The larger the value, the more the edges are eroded creating smaller and smaller cloud patches.

Multiplier on the Element Size parameter that effects the worley noise pattern.

This value controls how much the medium grey (noise values around 0.5) is pulled towards zero (if Bias is less than 1) or pulled towards one (if Bias is greater than 1). A value of 0.5 leaves the noise values unaffected.

Controls how much the medium greys (noise values around 0.5) are pulled together, while values around 0 and 1 are pulled apart. The value of 0.5 leaves the noise values unaffected.

Controls the overall gamma of the generated noise. Values less than 1 will darken the noise, increasing the range of values in originally bright areas. Conversely, values greater than 1 will stretch out the range of values for originally dark areas, which will increase the overall brightness of the noise.

This value expands or shrinks the overall range of tonal values. Particularly, each noise value is pushed towards (if Contrast is less than 1) or away from (if Contrast is greater than 1) medium grey (noise values at 0.5).

Computes the complement of the noise by subtracting the generated noise from 1.

The number of iterations of distortion to add to the output of the basic noise. The more iterations you add, the more “detailed” the output. Note that the output may have fewer octaves than this parameter (that is, increasing the parameter will eventually stop adding detail), because the node eventually stops when there’s no more room to add more detail in the output.

The frequency increment between iterations of fractal noise added to the basic output. Note that you can use a negative value.

The scale increment between iterations of fractal noise added to the basic output. The higher the value the larger the “jaggies” added to the output. You can use a negative value for roughness.

Controls how much the noise is distorted in the direction of decreasing noise values if Distortion is greater than 1, and in the direction of increasing noise values if Distortion is less than 1. When worley details are added to the noise pattern, the effect of distortion are largely diminished.

Distortion with a value of 1:

Distortion with a value of -1:

How much to stretch the noise in each direction. The advantage of using this instead of Element Size is that it preserves some details unstretched, making the stretched noise pattern more natural looking.

Comparing Element Scale of 3 (left) to Stretch value of 3 (right) along the X-axis:

Warps the generated noise such that the noise pattern is bending or hanging towards the given droop direction.

Noise pattern without (left) and with droop applied (right):

The direction in which the noise is warped.

Remaps the values between -1 and 1 and flips values below 0 to the positive range, so all valleys become peaks.

Smooths the density of the fog volume at the edge of the clipping plane.

Controls how much the fog volume at the edge of the clipping plane should be smoothed into the volume. Use this to soften the otherwise very harsh volume clipping.

When this is turned on, use the ramp to change the density smoothing into the fog volume.

Controls how the density at the edge of the clipping plane smooths into the volume.

When this is turned on, outputs an additional mask volume (named by Clip Mask Name) that for each voxel stores the distance from the clipping plane. Use this mask to further modify (for example using the Cloud Wispy Noise) the clipped volume with varying strength according to this mask.

Toggle visualization of the clip mask

The minimum and maximum distance from the clipping plane.

When this is turned on, use the ramp to change the density between minimum and maximum distance from the clipping plane.

Use this ramp to control the density between minimum and maximum distance from the clipping plane.

The computed bounding box of the incoming volume is enlarged by these padding values. As you might apply volume displacement after this node on the clipped volume (for example using Cloud Wispy Noise), the bound of this mask must be large enough to encompass the displaced clipped volume.

The computed bounding box of the incoming volume is enlarged by these padding values. As you might apply volume displacement after this node on the clipped volume (for example using Cloud Wispy Noise), the bound of this mask must be large enough to encompass the displaced clipped volume.

The name of the volume to be used as density. Usually you should leave this as density.

The name of the volume to be used as mask for the second input. Usually you should leave this as mask.

The name of the clip mask volume to be used as mask for further processing the clipped volume. Usually you should leave this as mask.