Experimental:TOP to CHOP

Summary

The TOP to CHOP converts pixels in a TOP image to CHOP channels. Each pixel color element (RGBA) is placed in a separate channel. Depending on the parameter options, the node will either create a single set of channels for the whole image or it can create a separate set of channels for each scanline (row).

A single pixel, rows of pixels, columns of pixels or rectangular regions can be extracted from the image. It is therefore important to be aware of how many pixels your source image is composed of.

The Exclude NaN and Active Mask parameters can be used to skip certain pixels so they are not included in the chop channels.

There is an optional input which supplies UV coordinates to sample the image. The input CHOP must contain 2 channels, for U and V. The first channel is always assumed to be U. The channels produced (red, green, blue and alpha) will be exactly as long as the input channel's length, with a value for each UV coordinate.

If you are grabbing pixels from a Depth TOP, you will only get a single channel (the depth). This will be placed in the R channel.

toptoCHOP_Class

Parameters - Image Page

TOP top - Specify the TOP operator whose image will be sampled.

Download Type downloadtype - ⊞ - Gives the option for a delayed data download from the GPU, which is much faster and does not stall the render.

• Immediate (Slow) immediate -

• Next frame (Fast) nextframe -

Red r - The prefix for channels created from the red pixels of the source image. If multiple red channels are created, they will have a numeric suffix that matches the vertical scanline number of the image e.g. r0 - r4.

Green g - The prefix for channels created from the green pixels of the source image. If multiple green channels are created, they will have a numeric suffix that matches the scanline number of the image e.g. g0 - g4.

Blue b - The prefix for channels created from the blue pixels of the source image. If multiple blue channels are created, they will have a numeric suffix that matches the scanline number of the image e.g. b0 - b4.

Alpha a - The prefix for channels created from the alpha pixels of the source image. If multiple alpha channels are created, they will have a numeric suffix that matches the scanline number of the image e.g. a0 - a4.

Output Color Space outputcolorspace - ⊞ - Controls what color space the data will be converted to before output. If the output (file/SDI/ST2110 etc) supports metadata, will also attempt to include the color space in that. Some output forms only support a limited number of color spaces in their metadata. If the color space is unknown to the output form, then no metadata will be included.

• sRGB srgb - sRGB color space, with sRGB transfer function. Considered an SDR color space with respect to Reference White.

• sRGB - Linear srgblinear - sRGB color space, with linear transfer function. Considered an SDR color space with respect to Reference White.

• Rec.601 (NTSC) rec601ntsc - Rec.601 with NTSC primaries color space, with Rec.601 transfer function. Considered an SDR color space with respect to Reference White.

• Rec.709 rec709 - Rec.709 color space, with Rec.709 (same as Rec.2020) transfer function. Considered an SDR color space with respect to Reference White.

• Rec.2020 rec2020 - Rec.2020 color space, with Rec.2020 (same as Rec.709) transfer function. Considered an HDR color space with respect to Reference White.

• Rec.2020 ST2084PQ rec2020st2084pq - Rec.2020 color space, with Perceptual Quantizer transfer function. Considered an HDR color space with respect to Reference White.

• Rec.2020 HLG rec2020hlg - Rec.2020 color space, with Hybrid Log Gamma transfer function. Considered an HDR color space with respect to Reference White.

• DCI-P3 dcip3 - DCI-P3 color space, with D65 white point and 2.6 gamma transfer function. Considered an HDR color space with respect to Reference White.

• DCI-P3 (D60) dcip3d60 - DCI-P3 "D60 sim" color space, with D60 white point, and 2.6 gamma transfer function. Considered an HDR color space with respect to Reference White.

• Display-P3 (D65) displayp3d65 - Display-P3 color space, with D65 white point, and sRGB gamma transfer function. Considered an HDR color space with respect to Reference White.

• Display-P3 (D65) - Linear displayp3d65linear - Display-P3 color space, with D65 white point, and linear transfer function. Considered an HDR color space with respect to Reference White.

• ACES2065-1 aces2065-1 - ACES 2065-1 (also known as ACES AP0) color space, with a linear gamma transfer function. Considered an HDR color space with respect to Reference White.

• ACEScg acescg - ACEScg (also known as ACES AP1) color space, with a linear gamma transfer function. Considered an HDR color space with respect to Reference White.

• ACESproxy acesproxy - ACESproxy color space, which has a log transfer function. Considered an HDR color space with respect to Reference White.

• Passthrough passthrough - When selected, the color values will be used as-is in the operation, without any modification or attempt to convert them into the Working Color Space.

Output Reference White outputreferencewhite - ⊞ - When converting the color values to the Working Color Space for output, this controls how they should be treated with respect to Reference White. If the Working Color Space is the same Reference White, then no adjustment is done. If they are different, then the Reference White level (brightness) of the colors will be adjusted to the range expected by the Output Color Space. For example if the project is set to have a SDR Reference White of 120 nits, and the HDR Reference White is 80 nits, and the project Working Color Space is HDR while the Output Color Space is SDR: then a color of (1, 1, 1), which is 80 nits in the HDR color space, will be converted to be (0.66, 0.66, 0.66), which is 80 nits still in the SDR Output Color Space.

• Default For Color Space default - Will use either the SDR or the HDR Reference White, based on the color space detected/selected.

• Standard (SDR) sdr - Will treat the Output Color Space as SDR for it's reference white value.

• High (HDR) hdr - Will treat the Output Color Space as HDR for it's reference white value.

Output as Single Channel Set singleset - Controls whether a channel is created for each scanline, or whether all scanlines are appended into a single channel set. A channel set refers to one CHOP channel per color channel of the source image e.g. 4 channels for an RGBA image.

Exclude NaNs excludenans - When enabled, pixels that have a NaN value in any of their channels will be skipped and not added to the CHOP channel.

Active Channel activechannel - ⊞ - When enabled, only pixels that have a non-zero value in the selected active channel will be added to the CHOP channel.

• None none -

• Red red -

• Green green -

• Blue blue -

• Alpha alpha -

RGBA Units rgbaunit - ⊞ - Scales the output to lie in the range 0-1, 0-255 or 0-65535.

• 0 to 1 u1 -

• 0 to 255 u256 -

• 0 to 65535 u65536 -

Parameters - Crop Page

Crop crop - ⊞ - Specifies what to extract from the image.

• Pixel (U,V) pixel - Extract a single pixel at the given U and V value.

• Row (U) row - Extract a single row at the given U value, cropped by the V Start and V End on the left and right.

• Column (V) col - Extract a single column at the given V value, cropped by the U Start and U End on the bottom and top.

• Rows and Columns block - Extract multiple rows and multiple columns, bound by the U/V Start/End parameters.

• Full Image full - Extract the full image.

UV Units uvunits - ⊞ - Specifies the units for the following 4 parameters. The parameters can use the local variables $NR and $NC for the number of rows and columns.

• 0 to 1 norm -

• Pixels pixel -

U Start ustart - Starting point for sampling in U. Values outside the range of the image are determined by the image's extend conditions, in the extend page.

U End uend - Ending point for sampling in U.

V Start vstart - Starting point for sampling in V.

V End vend - Ending point for sampling in V.

Interpolate interp - ⊞ - Determines the interpolation method when UV sampling with an input CHOP.

• Nearest Sample nearest -

• Linear linear -

Parameters - Extend Page

Image Left imageleft - ⊞ - The image extend conditions when sampling the image with U less than 0.

• Hold hold -

• Cycle cycle -

• Mirror mirror -

• Default Color default -

Image Right imageright - ⊞ - The image extend conditions for U greater than 1.

• Hold hold -

• Cycle cycle -

• Mirror mirror -

• Default Color default -

Image Bottom imagebottom - ⊞ - The image extend conditions for V less than 0.

• Hold hold -

• Cycle cycle -

• Mirror mirror -

• Default Color default -

Image Top imagetop - ⊞ - The image extend conditions for V greater than 1.

The extend conditions are:

• Hold hold - Use the first or last pixel value.

• Cycle cycle - Loop back to the other side of the image.

• Mirror mirror - Zig-zag back into the image.

• Default Color default - Use a default color specified below.

Default Color defcolor - ⊞ - The color to use when outside the bounds of the image, and the Default Color extend condition is set.

• Red defcolorr -

• Green defcolorg -

• Blue defcolorb -

• Alpha defcolora -

Parameters - Channel Page

Start start - The start position of the channel, expressed in units set by the units menu to the right (samples, frames or seconds). The channel length is determined by the number of pixels in each scanline that is converted into a channel.

Start Unit startunit - ⊞ - Select the units to use for this parameter, Samples, Frames, or Seconds.

• I samples -

• F frames -

• S seconds -

Sample Rate rate - The sample rate of the channels, in samples per second.

Extend Left left - ⊞ - The left extend conditions (before/after range).

• Hold hold - Hold the current value of the channel.

• Slope slope - Continue the slope before the start of the channel.

• Cycle cycle - Cycle the channel repeatedly.

• Mirror mirror - Cycle the channel repeatedly, mirroring every other cycle.

• Default Value default - Use the constant value specified in the Default Value parameter

Extend Right right - ⊞ - The right extend conditions (before/after range).

• Hold hold - Hold the current value of the channel.

• Slope slope - Continue the slope after the end of the channel.

• Cycle cycle - Cycle the channel repeatedly.

• Mirror mirror - Cycle the channel repeatedly, mirroring every other cycle.

• Default Value default - Use the constant value specified in the Default Value parameter

Default Value defval - The value used for the Default Value extend condition.

Parameters - Common Page

Time Slice timeslice - Turning this on forces the channels to be "Time Sliced". A Time Slice is the time between the last cook frame and the current cook frame.

Scope scope - To determine which channels get affected, some CHOPs use a Scope string on the Common page.

Sample Rate Match srselect - ⊞ - Handle cases where multiple input CHOPs' sample rates are different. When Resampling occurs, the curves are interpolated according to the Interpolation Method Option, or "Linear" if the Interpolate Options are not available.

• Resample At First Input's Rate first - Use rate of first input to resample others.

• Resample At Maximum Rate max - Resample to the highest sample rate.

• Resample At Minimum Rate min - Resample to the lowest sample rate.

• Error If Rates Differ err - Doesn't accept conflicting sample rates.

Export Method exportmethod - ⊞ - This will determine how to connect the CHOP channel to the parameter. Refer to the Export article for more information.

• DAT Table by Index datindex - Uses the docked DAT table and references the channel via the index of the channel in the CHOP.

• DAT Table by Name datname - Uses the docked DAT table and references the channel via the name of the channel in the CHOP.

• Channel Name is Path:Parameter autoname - The channel is the full destination of where to export to, such has geo1/transform1:tx.

Export Root autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is Path:Parameter are relative to.

Export Table exporttable - The DAT used to hold the export information when using the DAT Table Export Methods (See above).

Operator Inputs

• Input 0: -

TouchDesigner Build: Latest\nwikieditorwikieditor

An Operator Family that creates, composites and modifies images, and reads/writes images and movies to/from files and the network. TOPs run on the graphics card's GPU.

An Operator Family which operate on Channels (a sequence of numbers (Samples)) which are used for animation, audio, mathematics, simulation, logic, UI construction, and data streamed from/to devices and protocols.

The Graphics Processing Unit. This is the high-speed, many-core processor of the graphics card/chip that takes geometry, images and data from the CPU and creates images and processed data.

A Link. The grey dashed lines between nodes is a Reference or Link that indicates one operator is getting data from another operator from any Operator Family.

The grey dashed lines between nodes is a Reference (or Link). A Reference is (1) a Parameter Reference, a parameter in an OP that is a name or path to another operator, (2) a Node Reference, an expression in a parameter or DAT script that contains the name or path of another operator, (3) a DAT Cell Reference or (4) a CHOP Channel Reference.

A Link or Reference is a dashed line between nodes that represent other data flowing between nodes. Examples are CHOP Exports, node Paths in parameters, and expressions in parameters referencing CHOP channels, DAT tables and other nodes. In contrast is a Wire that connects nodes in the same Operator Family.

A CHOP outputs one or more channels, where a channel is simply a sequence of numbers (Samples), representing motion, audio, etc. Channels are passed between CHOPs in TouchDesigner networks. Channels can be Exported to Parameters.

samples-per-second of a CHOP. Each CHOP in your network has a sample rate. In contrast, the overall timeline has a Frame Rate, which is the number of frames to cook and display per second, generally your monitor display frequency, default 60.

samples-per-second of a CHOP. Each CHOP in your network has a sample rate. In contrast, the overall timeline has a Frame Rate, which is the number of frames to cook and display per second, generally your monitor display frequency, default 60.

A Time Slice is the time from the last cook frame to the current cook frame. In CHOPs it is the set of short channels that contain the CHOP channels' samples between the last and the current cook frame.

A parameter in most CHOPs that restricts which channels of that CHOP will be affected. Normally all channels of a CHOP are affected by the operator. TOPs have Channel Mask, a similar feature.

Exporting is the connection of CHOP channels to parameters of operators. The output of each exporting CHOP is one or more channels, active only while the CHOP Viewer is on. The current value of a channel can be exported to a parameter of any operator, overriding that parameter's value. See Parameter.

An Operator Family that manipulates text strings: multi-line text or tables. Multi-line text is often a python Script or GLSL Shader, but can be any multi-line text. Tables are rows and columns of cells, each containing a text string.

The location of an operator within the TouchDesigner environment, for example, /geo1/circle1, a node called circle1 in a component called geo1. The path / is called Root. This path is displayed at the top of every Pane, showing which Component's network you are currently in. To refer instead to a filesystem folder, directory, disk file or http: address, see Folder.

Every operator in TouchDesigner has a set of control Parameters that can be integer or floating point numbers, menus, binary toggles, text strings or operator paths, which determine the output of the operator.

TouchDesigner is a hierarchy of components. "root" is the top-most network in the hierarchy. The Network Path or Path for root is simply /. A typical path is /project1/moviein1.