CHOP to TOP

From TouchDesigner 088 Wiki

CHOPToTOP 10.jpg

Summary

The CHOP to TOP puts CHOP channels into a TOP image. By default the texture created will be 32-bit floating point to match the precision of the CHOP data. This can be changed setting the TOP's Pixel Format to something other than 'Input'.

The width of the image will be equal to the number of samples in the CHOP (the sample rate is ignored). The height will depend on how many channels need to be consumed for each scanline based on the Data Format parameter.


PythonIcon.png choptoTOP_Class

Parameters - CHOP to TOP Page

CHOP chop - The path of the CHOP being referenced.

Data Format dataformat - Determines how the input CHOP channels will be turned into an image. If the CHOP is missing channels required to provide all the data for a scanline, the extra channels are ignored.

  • R r - Each channel is treated as the Red channel for a new scanline. The height of the image will be equal to the number of channels in the CHOP.
  • RG rg - The first two channels will be the Red and Green channels for a scanline, the next two channels will be Red and Green for the next scanline, etc. The height of the image will be half the number of channels in the CHOP, rounded down.
  • RGB rgb - The first three channels will be the Red, Green and Blue channels for a scanline, the next three channels will be Red, Green and Blue for the next scanline, etc. The height of the image will be the number of channels in the CHOP divided by 3, rounded down.
  • RGBA rgba - The first four channels will be the Red, Green, Blue and Alpha channels for a scanline, the next four channels will be Red, Green, Blue and Alpha for the next scanline, etc. The height of the image will be the number of channels in the CHOP divided by 4, rounded down.
  • A a - Each channel is treated as the Alpha channel for a new scanline. The height of the image will be equal to the number of channels in the CHOP.
  • Legacy legacy - This mode only creates a single scanline in all cases. More than 4 channels will not do anything. If the CHOP has 1 or 2 channels, it will set R,G,B,A to the first channel of the CHOP. The 2nd channel is ignored. If it has 3 channels, it sets the 3 channels to R,G,B and A = sample number / # of samples (i.e A is a ramp starting at 0 and climbing to the (width -1). If it has 4 channels, they are set to R,G,B,A.


Clamp CHOP Values clamp - Clamps CHOP values to 0-1 range.

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.
  • Custom Resolution - enables the Custom Res parameter below, giving direct control over res in the X and Y axis.

Custom Res - 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.

Aspect Ratio - sets the image aspect ratio, which is the visible width vs height, independent of the pixel resolution. If the pixels are not square, the aspect ratio is not the resolution's width/height. Watch for unexpected results when compositing TOPs with different aspect ratios.

  • 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 Ratio - lets you explicitly define a custom aspect ratio.

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 Worst - 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. 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 mipmapfiltering 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 nearest filtering will always be used, regardless of what is selected in the menu.

Pixel Format - format used to store data for each channel in the image (ie. R, G, B, and A). 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.