Houdini 19.5 Compositing

Blend or layer images

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Useful nodes

  • The Layer COP is a general purpose compositor, which can composite any number of inputs, each with its own compositing method.

  • You can also use specific operators for each method on pairs of inputs (with the Over COP, Add COP, Multiply COP, etc.).

  • The Blend COP blends between its two inputs. It can blend with a constant value, or based on a mask .

  • The Wipe COP lets you quickly set up common wipe patterns. For complete control over a wipe, use an animated matte to mask a blend.


See compositing methods for an explanation of the different compositing methods available for combining images, such as over, add, and multiply.

Compositing methods

Original image A
Original image B
A over B
A under B
A atop B
A inside B
A outside B
A screen-ed over B.

“Saturating add”. Screening brightens the second image based on the luminosity of the first image. Where the first image is black, the second image will not be brightened at all. Where the first image is white, the second image will be white. Screen does not work well with HDR images.

A add-ed to B.

This simply adds the color values of the two images together.

A subtract-ed from B.

This simply subtracts the color values of A from B.

A diff B

This takes the absolute value of subtracting A from B.

A multiply by B.

This simply multiplies the color values of A and B. Multiplying with a grayscale matte is the same as masking .

A min B

Takes the minimum of A and B.

A max B

Takes the maximum of A and B.

A average B

Takes the average of A and B.

A Xor B

The union of A and B, except where A and B overlap.




Camera effects


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