Houdini 22.0 Nodes Copernicus nodes

Star Glow Copernicus node

Streaks the layer multiple times in different directions to create a star effect.

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Since 22.0

This node creates multiple streaks of an incoming layer, which is in the shape of a star by default. The node identifies high luminance areas (bright regions) in the layer and applies the star glow effect to those areas. Use the parameters on this node to adjust the streak weight, color, aberration, and glimmer. Use this node to add natural lighting effects to your layer.

For example, use this node to create flares and strobes.

You can use the Glow COP instead of this node when you want a glow effect in only one direction. You can use the Streak Blur COP instead of this node when you want to blur your layer in only one direction.

Parameters

Signature

The layer type that the source accepts.

See Signatures 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.

The default value is 1, which means this node uses only the new value. See Mask for more information.

Threshold

Any pixel with a luminance value above this threshold has the star glow effect. This lets you apply star glow to only high luminance parts of your source layer.

You can also use the effect input with this parameter to select where the effect happens.

Tip

Click and then click on the layer to set the Threshold.

Width

The range (in image space) on both sides of the Threshold that determines the input minimum and maximum.

Border

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

See Border types for more information.

Output Star Glow Only

Outputs only the star glow effect, which displays a preview of the effect. Turn this on if you want to make the star glow a separate AOV or configure the star glow further before you composite it on top of the source layer.

Tip

Turn this parameter on and use the Blend COP to put the star glow effect back over the original image.

Star Glow

Streaks

The amount of streaks in the layer. Each new streak takes up a space in 360 degrees.

A value of 2 means each streak is 180 degrees offset from each other. A value of 6 means each streak is 60 degrees offset from each other.

Streak Length

The overall strength (in image space) of the streaks. Negative values follow the directions backwards when tracing.

Brightness

The amount of brightness to apply to the star glow effect. Higher values increase the brightness to lighten and expand the star glow effect. Lower values decrease the brightness to dim and shrink the star glow effect.

Angle

The degree by which to offset the direction of all streaks.

Streak

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

Blur

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

Max

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

Streak Weight

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.

Color

Combine Streaks with

The blending operation used to combine the streaks before they're added onto the original layer. The node doesn’t add the combined streaks onto the original layer when Output Star Glow Only is on.

Add

Adds the streaks together.

Screen

Saturation adds the streaks together, similar to adding photographs.

Hypot

Uses the length of the vector formed by the streaks' channels.

Maximum

Uses the maximum of the streaks, per component.

Difference

Uses the absolute difference between the streaks.

Color Mode

The method used to color the streaks.

Uniform

Apply a singular color to all streaks.

Ramp

Apply a ramp across each streak. When Streaks is set to 4 for example, the first streak takes position 0.0 and the final streak takes position 1.0 on the ramp.

Multiply with Original

Multiplies the selected color with the color of the pixels in the original layer. When off, the selected color replaces the original layer’s color.

Color

The color to apply to all streaks.

Azimuth

The direction in degrees to cycle the ramp across each streak.

Color Ramp

The ramp to apply across each streak.

See Ramp parameters for more information.

Aberration

Aberration

Splits each streak into separate RGB streaks and composites them together. Each channel streak contributes to the final alpha when in RGBA mode.

Red

The amount (in degrees) to rotate the red channel by this angle. Higher values rotate the channel in a counterclockwise direction, which makes the offset between the channels more apparent. Lower values rotate the channel in a clockwise direction.

Green

The amount (in degrees) to rotate the green channel by this angle. Higher values rotate the channel in a counterclockwise direction, which makes the offset between the channels more apparent. Lower values rotate the channel in a clockwise direction.

Blue

The amount (in degrees) to rotate the blue channel by this angle. Higher values rotate the channel in a counterclockwise direction, which makes the offset between the channels more apparent. Lower values rotate the channel in a clockwise direction.

Glimmer

Glimmer

Applies noise to the streak lengths, which can create a subtle glimmering and shimmering effect.

Glimmer Strength

The amount that the noise affects (multiplies against) the streak lengths.

Glimmer Size

The size (in image space) of the basic element of the noise.

Animate

Implicitly adds time to the third coordinate.

Pulse Length

The interval length (in seconds) of the noise’s pulse in the third dimension. Lower values increase the rate at which the noise switches its appearance, while higher values decrease this rate.

Time Scale

The amount of time (in seconds) by which to multiply the start frame. Higher values increase the rate at which the noise switches its appearance, while lower values decrease this rate.

Loop Length (sec)

This is the time (in seconds) at which to repeat the noise. This clamps other options to enforce periodic behavior. Turn this on to generate animations that seamlessly loop.

When off, the animation generally doesn’t repeat after any amount of time.

Advanced

Maximum Steps

The maximum number of steps taken in the streak. Higher streak lengths can cause gaps, so increase this parameter to fill these gaps.

Inputs

source

The original layer to which you apply the star glow effect.

effect

An optional layer that controls which areas of the layer apply the star glow effect. Use this input along with the Threshold parameter.

mask

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

Outputs

starglow

The source layer with the star glow effect added. If Output Star Glow Only is on, this instead outputs only the star glow effect.

See also

Copernicus nodes