Composite TOP

From TouchDesigner 088 Wiki

CompositeTOP 08.jpg

Summary

The Composite TOP is a multi-input TOP that will perform a composite operation for each input. Select the composite operation using the Operation parameter on the Composite parameter page.

Note: See also the blendModes component in the Palette.

( some examples: Composite_TOP.tox. These and more are found in OP Snippets. )

PythonIcon.png compositeTOP_Class

Parameters - Composite Page

TOP top - In addition to all the inputs attached, you can specify more using the TOPs listed in this field. Example: ramp* will composite all TOPs whose name starts with ramp.

Preview Grid previewgrid - This outputs an image showing the effect of all operation types in a grid, with the inputs swapped on the right side of each tile.

Select Input selectinput - Instead of doing the composites, this causes only one of the inputs to pass through.

Input Index inputindex - When passing through an input with Select Input on, this is the index of the image that is passed through.

Operation operand - Choose which composite operation is performed from this menu. Search the web for 'blend modes' for more detailed information on the effects of each type.

  • Add : input1.rgba + input2.rgba
  • Atop : (input1.rgba * input2.a) + (input2.rgba * (1.0 - input1.a))
  • Average : (input1.rgba + input2.rgba)/2
  • Brightest
  • Burn Color
  • Burn Linear
  • Chroma Difference
  • Color
  • Darker Color
  • Difference : absoluteValue(input1.rgb - input2.rgb). Alpha always equals 1.0
  • Dimmest
  • Divide : input1.rgba / input2.rgba
  • Dodge
  • Exclude
  • Freeze
  • Glow
  • Hard Light
  • Hard Mix
  • Heat
  • Hue
  • Inside : input1.rgba * clamp(input2.a, 0.0, 1.0)
  • Inside Luminance
  • Inverse
  • Lighter Color
  • Luminance Difference
  • Maximum : max(input1.r, input2.r), max(input1.g, input2.g), max(input1.b, input2.b), max(input1.a, input2.a)
  • Minimum : min(input1.r, input2.r), min(input1.g, input2.g), min(input1.b, input2.b), min(input1.a, input2.a)
  • Multiply : input1.rgba * input2.rgba
  • Negate
  • Outside : input1.rgba * (1.0 - input2.a)
  • Outside Luminance
  • Over : (input2.rgba * (1.0 - input1.a)) + input1.rgba
  • Overlay
  • Pinlight
  • Reflect
  • Screen : 1.0 - ((1.0 - input1.rgba) * (1.0 - input2.rgba))
  • Soft Light
  • Linear Light
  • Stencil Luminance
  • Subtract : input1.rgba - input2.rgba
  • Subtractative
  • Under : (input1.rgba * (1.0 - input2.a)) + input2.rgba
  • Vivid Light
  • Xor : (input1.rgba * (1.0 - input2.a)) + (input2.rgba * (1.0 - input1.a))
  • Y Film
  • Z Film

Swap Operation Order swaporder - Swaps the order of the input pairs. A operation B is changed to B operation A. Operations like Add don't matter, but many do, like Over and Hard Light.

Parameters - Transform Page

All multi-input TOPs that have a Transform page (e.g. Multiply, Over, Composite) have the same set of parameters described here:

Fixed Layer /size - The Fixed Layer is Input 1 or Input 2. The other input will be the "overlay layer". This does not change the order of the composite (Input1 op Input2), only which layer is considered fixed and which layer is adjustable by the parameters on the Transform page. The resolution and aspect ratio of the Fixed Layer is used as the composite's final resolution and aspect ratio, unless it is manually set on the Common Page.

Pre-Fit Overlay /prefit - determines how the overlay layer is fit to the Fixed Layer.

  • Fill - The overlay layer is stretched/squashed to fill the resolution and aspect ratio of the Fixed Layer.
  • Fit Horizontal - The overlay layer is uniformly scaled to fit the Fixed Layer horizontally.
  • Fit Vertical - The overlay layer is uniformly scaled to fit the Fixed Layer vertically.
  • Fit Best - The overlay layer is uniformly scaled to fit the Fixed Layer using the best possible match that does not crop any of the overlay layer. It's a "fit inside". The aspect ratio of the overlay is maintained.
  • Fit Outside - This is the opposite of Fit Best. It is uniformly scaled so the overlay covers the Fixed Layer completely.
  • Native Resolution - The overlay is not scaled. The overlay layer uses its own resolution and aspect ratio during the composite. Pixel accurate composites require Native Resolution. Use this setting for to maintain an image's original resolution during the composite.

Extend Overlay /extend - Where the overlay layer does not cover the Fixed Layer, it sets the extend (or repeat) conditions of the overlay layer. This parameter determines what happens at the edges of the overlay layer.

  • Zero - The image does not extend past the edges of the overlay. It is filled with RGBA = 0.
  • Hold - The pixel values at the edges of the overlay layer continue to extend past that edge.
  • Repeat - The image is repeated at the edges of the overlay.
  • Mirror - The image is mirrored at the edges of the overlay.

NOTE: All the transform parameters below affect the overlay layer only.

Rotate /rotate - Rotates the overlay layer. Increasing values rotate clockwise, decreasing values rotate counter-clockwise.

Translate /translate[x-y] - Translates the overlay layer in x and y.

Translate Units menu /translateunits - Sets the unit used in the Translate parameter.

  • P - Pixels - units are pixels.
  • F - Fraction - units are set in fractions. The image's full width and height is 1 unit. 0.5 is halfway, or the middle of the image.
  • A - Fraction Aspect - same as Fraction except that the units are adjusted to compensate for aspect ratio. It is adjusted so a transform of a unit in x is the same distance as a transform of a unit in y, regardless of the aspect ratio of the images.

Scale /scale[x-y] - Scales the overlay layer in x and y.

Pivot /pivot[x-y] - Allows you to define the point about which the overlay layer scales and rotates. Altering the pivot point produces different results depending on the Transform Order.

Pivot Units menu /pivotunits - Sets the units used in the Pivot parameter.

  • P - Pixels - units are pixels.
  • F - Fraction - units are set in fractions. The image's full width and height is 1 unit. 0.5 is halfway, or the middle of the image.
  • A - Fraction Aspect - same as Fraction except that the units are adjusted to compensate for aspect ratio. It is adjusted so a transform of a unit in x is the same distance as a transform of a unit in y, regardless of the aspect ratio of the images.

Parameters - Common Page

Resolution - quickly change the resolution of the TOP's data.

  • Input - uses the input's resolution.
  • Eighth, Quarter, Half, 2X, 4X, 8X - multiply the input's resolution by that amount.
  • Fit Resolution - Resizes the input to the size specified in Resolution using the best possible match that does not crop any of the input. It will resize the image to be larger than the input resolution if a larger resolution is specified. It's a "fit inside", Aspect Ratio is maintained.
  • Limit Resolution - Limits the input to the size specified in Resolution using the best possible match that does not crop any of the input. It's a "fit inside", Aspect Ratio is maintained.
  • Custom Resolution - enables the Resolution parameter below, giving direct control over width and height.

Resolution - enabled only when the Resolution parameter is set to Custom Resolution. Some Generators like Constant and Ramp do not use inputs and only use this field to determine their size. The drop down menu on the right provides some commonly used resolutions.

Use Global Resolution Multiplier - Uses the Global Resolution Multiplier found in Edit>Preferences>TOPs. This multiplies all the TOPs resolutions by the set amount. This is handy when working on computers with different hardware specifications. If a project is designed on a desktop workstation with lots of graphics memory, a user on a laptop with only 64MB VRAM can set the Global Resolution Multiplier to a value of half or quarter so it runs at an acceptable speed. By checking this checkbox on, this TOP is affected by the global multiplier.

Output Aspect - sets the image aspect ratio allowing any textures to be viewed in any size. Watch for unexpected results when compositing TOPs with different aspect ratios. (You can define images with non-square pixels using xres, yres, aspectx, aspecty where xres/yres != aspectx/aspecty.)

  • Input - uses the input's aspect ratio.
  • Resolution - uses the aspect of the image's defined resolution (ie 512x256 would be 2:1), whereby each pixel is square.
  • Custom Aspect - lets you explicitly define a custom aspect ratio.

Input Smoothness - This controls pixel filtering on the input image of the TOP.

  • Nearest Pixel - uses nearest pixel or accurate image representation. Images will look jaggy when viewing at any zoom level other than Native Resolution.
  • Interpolate Pixels - uses linear filtering between pixels. This is how you get TOP images in viewers to look good at various zoom levels, especially useful when using any Fill Viewer setting other than Native Resolution.
  • Mipmap Pixels - uses mipmap filtering when scaling images. This can be used to reduce artifacts and sparkling in moving/scaling images that have lots of detail.

Fill Viewer - determine how the TOP image is displayed in the viewer.

  • Input - uses the same Fill Viewer settings as it's input.
  • Fill - stretches the image to fit the edges of the viewer.
  • Fit Horizontal - stretches image to fit viewer horizontally.
  • Fit Vertical - stretches image to fit viewer vertically.
  • Fit Best - stretches or squashes image so no part of image is cropped.
  • Fit Outside - stretches or squashes image so image fills viewer while constraining it's proportions. This often leads to part of image getting cropped by viewer.
  • Native Resolution - displays the native resolution of the image in the viewer.

NOTE: To get an understanding of how TOPs works with images, you will want to set this to Native Resolution as you lay down TOPs when starting out. This will let you see what is actually happening without any automatic viewer resizing.

Viewer Smoothness - This controls pixel filtering in the viewers.

  • Nearest Pixel - uses nearest pixel or accurate image representation. Images will look jaggy when viewing at any zoom level other than Native Resolution.
  • Interpolate Pixels - uses linear filtering between pixels. Use this to get TOP images in viewers to look good at various zoom levels, especially useful when using any Fill Viewer setting other than Native Resolution.
  • Mipmap Pixels - uses mipmap filtering when scaling images. This can be used to reduce artifacts and sparkling in moving/scaling images that have lots of detail. When the input is 32-bit float format, only nearest filtering will be used (regardless of what is selected).

Passes - duplicates the operation of the TOP the specified number of times.

Channel Mask - Allows you to choose which channels (R, G, B, or A) the TOP will operate on. All channels are selected by default.

Pixel Format - format used to store data for each channel in the image (ie. R, G, B, and A). Fixed format values are limited to the range [0-1]. Refer to Pixel Formats for more information.

  • Input - uses the input's pixel format.
  • 8-bit fixed (RGBA) - uses 8-bit integer values for each channel.
  • 16-bit float (RGBA) - uses 16-bits per color channel, 64-bits per pixel.
  • 32-bit float (RGBA) - uses 32-bits per color channel, 128-bits per pixels.


  • 10-bit RGB, 2-bit Alpha, fixed (RGBA) - uses 10-bits per color channel and 2-bits for alpha, 32-bits total per pixel.
  • 16-bit fixed (RGBA) - uses 16-bits per color channel, 64-bits total per pixel.
  • 11-bit float (RGB), Positive Values Only - A RGB floating point format that has 11 bits for the Red and Green channels, and 10-bits for the Blue Channel, 32-bits total per pixel (therefore the same memory usage as 8-bit RGBA). The Alpha channel in this format will always be 1. Values can go above one, but can't be negative. ie. the range is [0, infinite).
  • 8-bit fixed (R) - has 8-bits for the red channel, 8-bits total per pixel.
  • 16-bit fixed (R) - has 16-bits for the red channel, 16-bits total per pixel.
  • 16-bit float (R) - has 16-bits for the red channel, 16-bits per pixel.
  • 32-bit float (R) - has 32-bits for the red channel, 32-bits per pixel.
  • 8-bit fixed (RG) - has 8-bits for the red and green channels, 16-bits total per pixel.
  • 16-bit fixed (RG) - has 16-bits for the red and green channels, 32-bits total per pixel.
  • 16-bit float (RG) - has 16-bits for the red and green channels, 32-bits per pixel.
  • 32-bit float (RG) - has 32-bits for the red and green channels, 64-bits per pixel.
  • 8-bit fixed (A) - An Alpha only format that has 8-bits per channel, 8-bits per pixel.
  • 16-bit float (A) - An Alpha only format that has 16-bits per channel, 16-bits per pixel.
  • 32-bit float (A) - An Alpha only format that has 32-bits per channel, 32-bits per pixel.