Slope TOP

Summary

The Slope TOP generates pixels that represent the difference between its value and its neighbouring pixels' values. Given that default RGBA pixel values are between 0 and 1, the value of .5 means the neighbor's values are the same as the pixel's value. Values output in the red channel that are above .5 indicate the values are increasing left-to-right. Values output in the blue channel that are above .5 indicate the values are increasing bottom-to-top.

However it's more clear if you switch the Pixel Format parameter to 32-bit float RGBA so you get a proper representation of negative numbers. Also set the Zero Point parameter to 0, and view the TOP view as Normalized Split to see a good representation of negative numbers.

slopeTOP_Class

Parameters - Slope Page

Red red - ⊞ - Select which method is used to calculate the slope of the Red channel. Horizontal and Vertical options let you calculate the slope by sampling points horizontally or vertically.

• Horizontal Luminance hluminance - Uses the luminance values of the image to calculate slope.

• Horizontal Red hred - Uses the red channel of the image to calculate slope.

• Horizontal Green hgreen - Uses the green channel of the image to calculate slope.

• Horizontal Blue hblue - Uses the blue channel of the image to calculate slope.

• Horizontal Alpha halpha - Uses the alpha channel of the image to calculate slope.

• Horizontal RGB Average hrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Horizontal RGBA Average haverage - Uses the combined RGBA average of the image to calculate slope.

• Vertical Luminance vluminance - Uses the luminance values of the image to calculate slope.

• Vertical Red vred - Uses the red channel of the image to calculate slope.

• Vertical Green vgreen - Uses the green channel of the image to calculate slope.

• Vertical Blue vblue - Uses the blue channel of the image to calculate slope.

• Vertical Alpha valpha - Uses the alpha channel of the image to calculate slope.

• Vertical RGB Average vrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Vertical RGBA Average vaverage - Uses the combined RGBA average of the image to calculate slope.

• Neutral neutral - Sets that channel to the Zero Point.

• One one - Sets that channel to one.

• Zero zero - Sets that channel to zero.

Green green - ⊞ - Select which method is used to calulate the slope of the Green channel. Horizontal and Vertical options let you calculate the slope by sampling points horizontally or vertically.

• Horizontal Luminance hluminance - Uses the luminance values of the image to calculate slope.

• Horizontal Red hred - Uses the red channel of the image to calculate slope.

• Horizontal Green hgreen - Uses the green channel of the image to calculate slope.

• Horizontal Blue hblue - Uses the blue channel of the image to calculate slope.

• Horizontal Alpha halpha - Uses the alpha channel of the image to calculate slope.

• Horizontal RGB Average hrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Horizontal RGBA Average haverage - Uses the combined RGBA average of the image to calculate slope.

• Vertical Luminance vluminance - Uses the luminance values of the image to calculate slope.

• Vertical Red vred - Uses the red channel of the image to calculate slope.

• Vertical Green vgreen - Uses the green channel of the image to calculate slope.

• Vertical Blue vblue - Uses the blue channel of the image to calculate slope.

• Vertical Alpha valpha - Uses the alpha channel of the image to calculate slope.

• Vertical RGB Average vrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Vertical RGBA Average vaverage - Uses the combined RGBA average of the image to calculate slope.

• Neutral neutral - Sets that channel to the Zero Point.

• One one - Sets that channel to one.

• Zero zero - Sets that channel to zero.

Blue blue - ⊞ - Select which method is used to calulate the slope of the Blue channel. Horizontal and Vertical options let you calculate the slope by sampling points horizontally or vertically.

• Horizontal Luminance hluminance - Uses the luminance values of the image to calculate slope.

• Horizontal Red hred - Uses the red channel of the image to calculate slope.

• Horizontal Green hgreen - Uses the green channel of the image to calculate slope.

• Horizontal Blue hblue - Uses the blue channel of the image to calculate slope.

• Horizontal Alpha halpha - Uses the alpha channel of the image to calculate slope.

• Horizontal RGB Average hrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Horizontal RGBA Average haverage - Uses the combined RGBA average of the image to calculate slope.

• Vertical Luminance vluminance - Uses the luminance values of the image to calculate slope.

• Vertical Red vred - Uses the red channel of the image to calculate slope.

• Vertical Green vgreen - Uses the green channel of the image to calculate slope.

• Vertical Blue vblue - Uses the blue channel of the image to calculate slope.

• Vertical Alpha valpha - Uses the alpha channel of the image to calculate slope.

• Vertical RGB Average vrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Vertical RGBA Average vaverage - Uses the combined RGBA average of the image to calculate slope.

• Neutral neutral - Sets that channel to the Zero Point.

• One one - Sets that channel to one.

• Zero zero - Sets that channel to zero.

Alpha alpha - ⊞ - Select which method is used to calculate the slope of the Alpha channel. Horizontal and Vertical options let you calculate the slope by sampling points horizontally or vertically.

• Horizontal Luminance hluminance - Uses the luminance values of the image to calculate slope.

• Horizontal Red hred - Uses the red channel of the image to calculate slope.

• Horizontal Green hgreen - Uses the green channel of the image to calculate slope.

• Horizontal Blue hblue - Uses the blue channel of the image to calculate slope.

• Horizontal Alpha halpha - Uses the alpha channel of the image to calculate slope.

• Horizontal RGB Average hrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Horizontal RGBA Average haverage - Uses the combined RGBA average of the image to calculate slope.

• Vertical Luminance vluminance - Uses the luminance values of the image to calculate slope.

• Vertical Red vred - Uses the red channel of the image to calculate slope.

• Vertical Green vgreen - Uses the green channel of the image to calculate slope.

• Vertical Blue vblue - Uses the blue channel of the image to calculate slope.

• Vertical Alpha valpha - Uses the alpha channel of the image to calculate slope.

• Vertical RGB Average vrgbaverage - Uses the combined RGB average of the image to calculate slope.

• Vertical RGBA Average vaverage - Uses the combined RGBA average of the image to calculate slope.

• Neutral neutral - Sets that channel to the Zero Point.

• One one - Sets that channel to one.

• Zero zero - Sets that channel to zero.

Method method - ⊞ - Determines what pixels to use when calculating the slope at each pixel in the image.

• Use Previous And Current prevcur - Uses the previous and current pixels for slope calculation.

• Use Current And Next curnext - Uses the current and next pixels for slope calculation.

• Use Previous And Next prevnext - Uses the previous and next pixels for slope calculation.

Zero Point zeropoint - Sets the value to output when the slope is zero, similar to a midpoint. Default is .5 since 8-bit pxels are 0 to 1. But with Pixel Format et to 32-bit Float you should set this to 0, and look at the view in Normalized Split mode.

Strength strength - Set the strength of the output using this multiplier. Higher values result in higher slope values.

Sample Step offset - ⊞ - When sampling the image, this determines the distance from each pixel to the sample pixel. When units are set to pixels, it is the number of pixels away from the current pixel which is sampled to find edges. A Sample Step of 3 would sample pixels 3 pixels away to look for edges.

• offset1 -

• offset2 -

Sample Step Unit offsetunit -

Parameters - Common Page

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

• Use Input useinput - Uses the input's resolution.

• Eighth eighth - Multiply the input's resolution by that amount.

• Quarter quarter - Multiply the input's resolution by that amount.

• Half half - Multiply the input's resolution by that amount.

• 2X 2x - Multiply the input's resolution by that amount.

• 4X 4x - Multiply the input's resolution by that amount.

• 8X 8x - Multiply the input's resolution by that amount.

• Fit Resolution fit - Fits the width and height to the resolution given below, while maintaining the aspect ratio.

• Limit Resolution limit - The width and height are limited to the resolution given below. If one of the dimensions exceeds the given resolution, the width and height will be reduced to fit inside the given limits while maintaining the aspect ratio.

• Custom Resolution custom - Enables the Resolution parameter below, giving direct control over width and height.

Resolution 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.

• W resolutionw -

• H resolutionh -

Resolution Menu resmenu - A drop-down menu with some commonly used resolutions.

Use Global Res Multiplier resmult - 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 outputaspect - ⊞ - 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.)

• Use Input useinput - Uses the input's aspect ratio.

• Resolution resolution - Uses the aspect of the image's defined resolution (ie 512x256 would be 2:1), whereby each pixel is square.

• Custom Aspect custom - Lets you explicitly define a custom aspect ratio in the Aspect parameter below.

Aspect aspect - ⊞ - Use when Output Aspect parameter is set to Custom Aspect.

• Aspect1 aspect1 -

• Aspect2 aspect2 -

Aspect Menu armenu - A drop-down menu with some commonly used aspect ratios.

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

• Nearest Pixel nearest - Uses nearest pixel or accurate image representation. Images will look jaggy when viewing at any zoom level other than Native Resolution.

• Interpolate Pixels linear - 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 mipmap - 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 fillmode - ⊞ - Determine how the TOP image is displayed in the viewer.

NOTE:To get an understanding of how TOPs work 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.

• Use Input useinput - Uses the same Fill Viewer settings as it's input.

• Fill fill - Stretches the image to fit the edges of the viewer.

• Fit Horizontal width - Stretches image to fit viewer horizontally.

• Fit Vertical height - Stretches image to fit viewer vertically.

• Fit Best best - Stretches or squashes image so no part of image is cropped.

• Fit Outside 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 nativeres - Displays the native resolution of the image in the viewer.

Viewer Smoothness filtertype - ⊞ - This controls pixel filtering in the viewers.

• Nearest Pixel nearest - Uses nearest pixel or accurate image representation. Images will look jaggy when viewing at any zoom level other than Native Resolution.

• Interpolate Pixels linear - 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 mipmap - Uses mipmap filtering when scaling images. This can be used to reduce artifacts and sparkling in moving/scaling images that have lots of detail.

Passes npasses - Duplicates the operation of the TOP the specified number of times. Making this larger than 1 is essentially the same as taking the output from each pass, and passing it into the first input of the node and repeating the process. Other inputs and parameters remain the same for each pass.

Channel Mask chanmask - 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 - ⊞ - Format used to store data for each channel in the image (ie. R, G, B, and A). Refer to Pixel Formats for more information.

• Use Input useinput - Uses the input's pixel format.

• 8-bit fixed (RGBA) rgba8fixed - Uses 8-bit integer values for each channel.

• sRGB 8-bit fixed (RGBA) srgba8fixed - Uses 8-bit integer values for each channel and stores color in sRGB colorspace.

• 16-bit float (RGBA) rgba16float - Uses 16-bits per color channel, 64-bits per pixel.

• 32-bit float (RGBA) rgba32float - Uses 32-bits per color channel, 128-bits per pixels.

• 10-bit RGB, 2-bit Alpha, fixed (RGBA) rgb10a2fixed - Uses 10-bits per color channel and 2-bits for alpha, 32-bits total per pixel.

• 16-bit fixed (RGBA) rgba16fixed - Uses 16-bits per color channel, 64-bits total per pixel.

• 11-bit float (RGB), Positive Values Only rgba11float - 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).

• 16-bit float (RGB) rgb16float -

• 32-bit float (RGB) rgb32float -

• 8-bit fixed (Mono) mono8fixed - Single channel, where RGB will all have the same value, and Alpha will be 1.0. 8-bits per pixel.

• 16-bit fixed (Mono) mono16fixed - Single channel, where RGB will all have the same value, and Alpha will be 1.0. 16-bits per pixel.

• 16-bit float (Mono) mono16float - Single channel, where RGB will all have the same value, and Alpha will be 1.0. 16-bits per pixel.

• 32-bit float (Mono) mono32float - Single channel, where RGB will all have the same value, and Alpha will be 1.0. 32-bits per pixel.

• 8-bit fixed (RG) rg8fixed - A 2 channel format, R and G have values, while B is 0 always and Alpha is 1.0. 8-bits per channel, 16-bits total per pixel.

• 16-bit fixed (RG) rg16fixed - A 2 channel format, R and G have values, while B is 0 always and Alpha is 1.0. 16-bits per channel, 32-bits total per pixel.

• 16-bit float (RG) rg16float - A 2 channel format, R and G have values, while B is 0 always and Alpha is 1.0. 16-bits per channel, 32-bits total per pixel.

• 32-bit float (RG) rg32float - A 2 channel format, R and G have values, while B is 0 always and Alpha is 1.0. 32-bits per channel, 64-bits total per pixel.

• 8-bit fixed (A) a8fixed - An Alpha only format that has 8-bits per channel, 8-bits per pixel.

• 16-bit fixed (A) a16fixed - An Alpha only format that has 16-bits per channel, 16-bits per pixel.

• 16-bit float (A) a16float - An Alpha only format that has 16-bits per channel, 16-bits per pixel.

• 32-bit float (A) a32float - An Alpha only format that has 32-bits per channel, 32-bits per pixel.

• 8-bit fixed (Mono+Alpha) monoalpha8fixed - A 2 channel format, one value for RGB and one value for Alpha. 8-bits per channel, 16-bits per pixel.

• 16-bit fixed (Mono+Alpha) monoalpha16fixed - A 2 channel format, one value for RGB and one value for Alpha. 16-bits per channel, 32-bits per pixel.

• 16-bit float (Mono+Alpha) monoalpha16float - A 2 channel format, one value for RGB and one value for Alpha. 16-bits per channel, 32-bits per pixel.

• 32-bit float (Mono+Alpha) monoalpha32float - A 2 channel format, one value for RGB and one value for Alpha. 32-bits per channel, 64-bits per pixel.

Operator Inputs

• Input 0: -

Info CHOP Channels

Extra Information for the Slope TOP can be accessed via an Info CHOP.

Common TOP Info Channels

• resx - Horizontal resolution of the TOP in pixels.

• resy - Vertical resolution of the TOP in pixels.

• aspectx - Horizontal aspect of the TOP.

• aspecty - Vertical aspect of the TOP.

• depth - Depth of 2D or 3D array if this TOP contains a 2D or 3D texture array.

• gpu_memory_used - Total amount of texture memory used by this TOP.

Common Operator Info Channels

• total_cooks - Number of times the operator has cooked since the process started.

• cook_time - Duration of the last cook in milliseconds.

• cook_frame - Frame number when this operator was last cooked relative to the component timeline.

• cook_abs_frame - Frame number when this operator was last cooked relative to the absolute time.

• cook_start_time - Time in milliseconds at which the operator started cooking in the frame it was cooked.

• cook_end_time - Time in milliseconds at which the operator finished cooking in the frame it was cooked.

• cooked_this_frame - 1 if operator was cooked this frame.

• warnings - Number of warnings in this operator if any.

• errors - Number of errors in this operator if any.

TouchDesigner Build: Latest\n2021.100002018.28070before 2018.28070

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.

Each SOP has a list of Points. Each point has an XYZ 3D position value plus other optional attributes. Each polygon Primitive is defined by a vertex list, which is list of point numbers.

The width and height of an image in pixels. Most TOPs, like the Movie File In TOP can set the image resolution. See Aspect Ratio for the width/height ratio of an image, taking into account non-square pixels.

The viewer of a node can be (1) the interior of a node (the Node Viewer), (2) a floating window (RMB->View... on node), or (3) a Pane that graphically shows the results of an operator.

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.

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.