Houdini 21.0 Nodes Copernicus nodes

Distort Copernicus node

Distorts an input layer.

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This node distorts an incoming layer. It can perform the distortion in a fixed direction (while possibly varying strength) or by tracing through vectors of an input UV layer.

Tip

The Distort By Slope recipe will put down a Distort COP and a Slope Direction COP that plugs into the dir input of the Distort COP. This distorts the source image by pushing away from larger values of the Mono layer controlling the slopes towards the lower ones.

Parameters

Signature

The layer type that the source accepts.

See Signatures for more information.

Border

The sampling behavior outside of the incoming layer’s boundaries. Automatically uses the layer’s border property.

See Border types for more information.

Filter

The filtering method used for sampling the source layer. Consider using one of the area filters (Box and later) if the distortion shrinks large regions and you notice noise.

See Filters for more information.

Mask

The amount of the new value to mix in with the original value. Higher values mix in more of the new value. Lower values mix in less of the new value. A value of 1 means this node uses only the new value.

The default value is 1. See Mask for more information.

Direction Type

Specifies the direction in which to distort the layer. This can be an angle in degrees (Angle) or a two-component vector representing the X and Y directions in image space (Coordinates).

Direction

Specifies the X and Y directions in image space when Direction Type is set to Coordinates.

Normalize Direction

Normalizes Direction when turned on.

Angle

Specifies the angle of distortion when Direction Type is set to Angle. Value of 0 corresponds to the positive X direction in image space.

Scale

Overall strength of distortion. Negative values follow the directions backwards when tracing.

Scale by Timestep

Adjusts the distortion’s overall strength by the current timestep. The timestep is usually 1/$FPS, but in a sub-stepped simulation it represents the current step size.

Streak

The method used to combine the pixel values along the direction of distortion.

Off

Don’t smear the image.

Blur

Average the samples together. This smears the image along the distortion direction.

Min

Accept the smallest value encountered along the trajectory. This is useful when eroding an input shape.

Max

Accept the largest value encountered along the trajectory. This is useful when adding edge roughness on an input shape.

Use Streak Weight Ramp

When Streak is Blur, Min, or Max , weight the samples encountered along the path. Use Streak Weight to weaken the values over the trajectory.

Streak Weight

When Use Streak Weight Ramp is on, this ramp acts as a multiplier on the pixel values when streaking. The left side of the ramp corresponds to the start of the trajectory.

For example, when the Streak is Blur, the default linear ramp fades the pixels over their path. This makes the pixels more faint near the start.

For more information about using ramps, see Ramp parameters.

Pixels per Step

When off, a single step is taken for each pixel to figure out the source location. Although this is fast, it produces inaccurate results when the directions or scales vary. Turning on this parameter uses a more accurate algorithm to trace curved trajectories. The provided value controls the tracing quality. More pixels per step allows the node to take larger steps (this runs faster, but may miss intermediate variations in the distortion directions).

Maximum Steps

Clamps the number of steps taken when Pixels per Step is on. You can raise this parameter (and lower Pixels per Step) if the distortion doesn’t faithfully follow the directions. This can be especially noticeable when Streak is turned on.

Inputs

source

The original layer to distort.

dir

If you connect to this input, this is the per-pixel direction to distort along.

scale

If you connect to this input, this is the per-pixel scale amount. The value of this layer acts as a multiplier on the Scale parameter.

mask

An optional per-pixel mask amount that’s scaled by the Mask parameter.

Outputs

distort

The distorted output layer.

Copernicus nodes