Game Dev perspectives of Houdini SOP (Composite Operator Node) nodes.

Current with Houdini 17.5.360

Color

  • Bright – Applies a brightness factor and bright shift to the first input.
  • Color – Creates a constant color image.
  • Color Correct – Applies a variety of color corrections to the image.
  • Color Curve – Adjusts the R,G,B and/or A channels based on a user-defined curve.
  • Color Map – Maps a range of color to a new range.
  • Color Replace – Replace a color region in an image with another region.
  • Contrast – Increases or decreases the contrast of an image.
  • Equalize – Equalizes colors by stretching or shifting the image histogram.
  • Gamma – Applies gamma correction to the image.
  • HSV – Converts between RGB and HSV color spaces, or applies hue and saturation modifications.
  • Hue Curve – Adjusts the saturation or luminance of the image based on hue.
  • Levels – Adjusts black point, white point, and midrange to increase, balance, or decrease contrast.
  • Limit – Limits the pixel range at the high end, low end or both.
  • Lookup – Applies a lookup table to the input.
  • Mono – Converts a color or vector into a scalar quantity, like luminance or length.
  • Pixel – Modifies an image’s pixels using expressions.
  • Premultiply – Allows colour to be converted to or from a premultiplied form.
  • Quantize – Quantizes input data into discrete steps.
  • Vector – Performs vector operations on the input.

Comps

  • Add – Adds two images together.
  • Anaglyph – Creates an anaglyph from a pair of input images.
  • Atop – Composites the first input (Foreground) over the second (background), but only where the background alpha exists.
  • Average – Averages the foreground image and the background image.
  • Blend – Blends frames from two sequences together using a simple linear blend.
  • Composite – Does a composite (over, under, inside, add, etc) between two images.
  • Diff – Computes the difference between the foreground image and the background image.
  • Inside – Restricts the foreground color to the area of the background’s alpha matte.
  • Layer – Layers a series of inputs together by compositing them one by one on the background image (input 1).
  • Max – Masks out an area of an image.
  • Min – Outputs the minimum value of the foreground and background images for each pixel, which tends to darken the image.
  • Multiply – Multiplies the foreground image with the background image.
  • Outside – Restricts the foreground color to the area outside of the background’s alpha matte.
  • Over – Composites the first input (Foreground) over the second (background).
  • Screen – Adds two images together, saturating at white like photographic addition.
  • Subtract – Subtracts the foreground image from the background image.
  • Under – Composites the first input (Foreground) under the second (background).
  • Wipe – Does a wipe between two input sequences.
  • Xor – Makes two elements mutually exclusive; if their alpha mattes overlap, the overlap is removed.
  • Z Composite – Does a Z composite of two images.

Effects

  • Blur – Blurs an image.
  • Border – Adds a border to the image.
  • Bump – Builds a bump map from a plane.
  • Convolve – Performs a generic convolve on the source image.
  • Corner Pin – Fits an image into an arbitrary quadrilateral.
  • Defocus – Defocuses an image similar to a real camera defocus.
  • Deform – Deforms an image by moving the underlying UV coordinates.
  • Degrain – Removes film grain from an image.
  • Denoise – Removes white noise from an image.
  • Depth Darken – Darkens depth boundaries in an image.
  • Depth of Field – Creates a depth-of-field mask, which describes how out of focus parts of the image are.
  • DilateErode – Expands and shrinks mattes.
  • Drop Shadow – Creates a blurred shadow offset of an image.
  • Edge Blur – Blurs the edges of an image.
  • Edge Detect – Detects edges in the input image.
  • Emboss – Adds a lighting effect to the image by using a bump map.
  • Environment – Applies an environment map to an image.
  • Expand – Expands and shrinks mattes.
  • Fog – Adds a variety of atmospheric effects to an image, including fog, haze and heat waves.
  • Function – Performs a variety of mathematical functions on the input image.
  • Grain – Adds grain to an image.
  • Lighting – Adds a light to the image.
  • Median – Applies a 3 x 3 or 5 x 5 median filter to the input image.
  • Mosaic – Takes a sequence of images and combines them into 1 image by tiling them.
  • Noise – Generates continuous noise patterns.
  • Pixel – Modifies an image’s pixels using expressions.
  • Quantize – Quantizes input data into discrete steps.
  • Radial Blur – Does a radial or angular blur.
  • Sharpen – Sharpens an image by enhancing the contrast of edges.
  • Streak Blur – Streaks an image, adding a motion blur effect.
  • Tile – Tiles the image sequence with multiple copies of the input image.
  • Time Filter – Blurs a pixel through several frames.
  • Time Machine – Uses a second input to time warp the first input on a per pixel basis.
  • Transform – Translates, rotates and/or scales the input image without changing the image resolution.
  • Velocity Blur – Blurs an image by using pixel velocity to produce a motion blur effect.

Export

  • ROP File Output – Renders frames out to disk.

Import

  • DSM Filter –
  • Fetch – Fetches a sequence of images from another COP, even in another network.
  • File – Loads image files into Houdini.
  • Geometry – Renders geometry from a SOP as a single color image.
  • Render – Renders a mantra output driver directly into a composite network.
  • SOP Import – Imports a 2d Volume from SOPs as planes into a composite network.

Keying

  • Chromakey – Mask or “key” an image based on its color.
  • Geokey – Keys out parts of the image based on pixel position or normal direction.
  • Lumakey – Keys the image based on luminance (or similar function).
  • LumaMatte – Sets the alpha to the luminance of the color.

Managers

  • CHOP Network – Channel nodes create, filter, and manipulate channel data.
  • COP2 Network – Composite nodes create, filter, and manipulate image data.
  • DOP Network – Dynamics nodes set up the conditions and rules for dynamics simulations.
  • Material Network –
  • Object Network – Object nodes represent objects in the scene, such as character parts, geometry objects, lights, cameras, and so on.
  • ROP File Output –
  • ROP Network – Render nodes either render the scene or set up render dependency networks.
  • SHOP Network – Deprecated.
  • SOP Network – Geometry nodes live inside Geo objects and generate geometry.
  • TOP Network – TOP nodes live inside TOP objects and do work.
  • VOP Network – VOP nodes let you define a program (such as a shader) by connecting nodes together. Houdini then compiles the node network into executable VEX code.

Matte

  • Border – Adds a border to the image.
  • Color – Creates a constant color image.
  • Corner Ramp – Generates a four corner ramp.
  • Cryptomatte – Extracts matte from Cryptomatte image.
  • Expand – Expands and shrinks mattes.
  • Font – Renders anti-aliased text.
  • Geometry – Renders geometry from a SOP as a single color image.
  • Mask – Masks out an area of an image.
  • Ramp – Generates a variety of linear and radial ramps, which are fully keyframable.
  • RotoShape – Draws one or more curves or shapes.
  • Shape – Generates simple shapes, such as circles, stars and regular N-sided polygons.
  • Sky Environment – Creates sky and ground images for use as environment maps.

PixelOp

  • Bright – Applies a brightness factor and bright shift to the first input.
  • Contrast – Increases or decreases the contrast of an image.
  • Function – Performs a variety of mathematical functions on the input image.
  • Gamma – Applies gamma correction to the image.
  • HSV – Converts between RGB and HSV color spaces, or applies hue and saturation modifications.
  • Invert – Applies a photographic pixel inversion to the image.
  • Levels – Adjusts black point, white point, and midrange to increase, balance, or decrease contrast.
  • Limit – Limits the pixel range at the high end, low end or both.
  • Lookup – Applies a lookup table to the input.
  • Mono – Converts a color or vector into a scalar quantity, like luminance or length.
  • Quantize – Quantizes input data into discrete steps.
  • Vector – Performs vector operations on the input.

Timing

  • Deinterlace – De-interlaces a frame of video by either averaging scanlines or copying a scanline.
  • Extend – Extends the length of a sequence so that it can be animated beyond its frame range.
  • Field Merge – Merges two fields into one Interlaced Frame.
  • Field Split – Splits an interlaced frame into two fields per frame (odd and even fields).
  • Field Swap – Swaps the two fields containing the even and odd scanlines of the frame.
  • Interleave – Interleaves image sequences.
  • Pulldown – Performs a pulldown (cine-expand) on the input sequence.
  • Pushup – Performs a pushup (cine-expand) on the input sequence.
  • Reverse – Simply reverses the frames in the sequence.
  • Sequence – Sequences two or more inputs end to end.
  • Shift – Shifts an image sequence in time.
  • Shuffle – Shuffle frames around to do out-of-order editing.
  • Snip – Either removes frames from a sequence or allows you to order them in a user-defined order.
  • Time Filter – Blurs a pixel through several frames.
  • Time Machine – Uses a second input to time warp the first input on a per pixel basis.
  • TimerScale – Stretches or compresses a sequence in time.
  • TimeWarp – Warps time by slowing or speeding it up throughout the sequence.
  • Trim – Trims an input sequence in time by adjusting the beginning or the end of the sequence.

Transform

  • Corner Pin – Fits an image into an arbitrary quadrilateral.
  • Crop – Crops an image and changes its resolution.
  • Scale – Changes the resolution of the image.
  • Transform – Translates, rotates and/or scales the input image without changing the image resolution.
  • UnPin – Extracts an arbitrary quadrilateral area out of the input image.
  • Window – Cuts a small window out of a larger image.

Utility

  • Channel Copy – Copy channels from any of inputs into the output image.
  • Color Wheel –  Generates a simple HSV color wheel.
  • Convert – Changes the data format of a plane.
  • Crop – Crops an image and changes its resolution.
  • Delete – Removes planes or components from an input sequence.
  • Error Function Table Generator – Creates an image containing precomputed error function terms for hair albedo computation.
  • Fetch – Fetches a sequence of images from another COP, even in another network.
  • Flip – Flips the image horizontally and/or vertically.
  • Front Face – Cleans up flipped normals by making them face the camera.
  • Gradient – Computes the gradient of an image.
  • Illegal Pixel – Detects illegal pixels, like NAN and INF, in images.
  • Loop – Cooks the subnet COPs multiple times in a loop, accumulating the results.
  • Merge – Merges the planes of several inputs together.
  • Metadata – Applies metadata to an image sequence.
  • Null – Does nothing.
  • Premultiply – Allows colour to be converted to or from a premultiplied form.
  • Reference – Copies the sequence information from its input.
  • Rename – Change the name a plane.
  • Scale – Changes the resolution of the image.
  • Subnetwork – Contains networks of other COPs.
  • Switch – Passes the input of one of its connected inputs through, acting like an exclusive switch.
  • Switch Alpha – Replaces input 1’s alpha with input 2’s alpha.
  • UV Map – Creates a UV map.

Vex

  • VEX Filter – Runs a VEX script on its input planes.
  • VEX Generator – Runs a VEX script on the planes it generates.
  • VOP COP2 Filter – Contains a VOP network that filters input image data.
  • VOP COP2 Generator – Contains a VOP network that generates image data.