From TouchDesigner 088 Wiki

OP TOP.png

See also Category:TOPs for a full list of articles related to TOPs.

Texture Operators, also known as TOPs, are image operators that provide real-time, GPU-based compositing and image manipulation. All calculations for TOPs are performed on the system's GPU. TOPs can be used for preparing textures, compositing streams images and movies, building control panel elements, and almost any other image task you might have. TOPs support many formats, including floating-point image formats for working with high-dynamic range (HDR) images.

All renders and composites occur offscreen with TOPs. Data can be scaled to any resolution, limited only by the amount of graphics RAM and the maximum resolution of the graphics card.

NOTE: TouchDesigner Non-Commercial is limited to 1280x1280 resolution.

Sweet 16 TOPs

The following 16 TOPs are commonly used, we recommend familiarizing yourself with them.

TOP Videos Purpose Related TOP
Movie File In TutorialBeginner.png Read movies, still images, or a sequence of still images. Video Device In, Movie File Out
Ramp TutorialBeginner.png Create vertical, horizontal, radial, and circular ramps. Constant, Noise
Level TutorialBeginner.png Adjust contrast, brightness, gamma, black level, color range, opacity. Luma Level
Transform TutorialBeginner.png Translate, scale, rotate, multi-repeat tile, background fill. Flip
Over TutorialBeginner.png Place and shift one image over another based on the alpha of one image. Cross, Multiply
Text TutorialBeginner.png Text generation with variety of fonts.
Blur TutorialBeginner.png Blur. Luma Blur
Composite TutorialBeginner.png Combine multiple images with variety of operations like under, difference.
Render TutorialBeginner.png Render 3D objects, lights and camera into an image.
CHOP to TutorialBeginner.png Convert CHOP channels into scanlines of an image.
Resolution TutorialBeginner.png Change the resolution of an image and smooth-filter down. all TOPs alter resolution
Crop TutorialBeginner.png Crop image to smaller resolution. Corner Pin, Fit
Select TutorialBeginner.png Selects an image from the same network or a different network. Switch
Reorder TutorialBeginner.png Re-order the channels of an image. Channel Mix
Cache TutorialBeginner.png Hold a static or dynamic sequence of images and output one of them. Feedback
Displace TutorialBeginner.png Use red-blue of one image to warp another image. Time Machine

All TOPs are documented in the Category:TOPs.

TOP Flags

The lower right corner contains only 2 flags, the TOP’s Display Flag and Viewer Active Flag. Turning on the display flag displays the TOP as a background in the current Network Pane. Turning on multiple TOP Display Flags will display a tiled sequence of multiple TOP outputs as the background of the network pane.

TOPDisplaySingle.jpg TOPDisplayMulti.jpg

TOP Viewers

All TOP operators have interactive Node Viewers. To interact with it, turn on the TOP's Viewer Active Flag to make the viewer active.


A gray checkerboard background will be displayed in images where an alpha channel is present. This can be turned off by opening Preferences in the Edit menu. In preferences you can choose to use checkerboard or black as you alpha background.

Use LMB to move the image around. Use MMB to zoom in and out of the image. Re-center the image by using the home shortcut "h".

Clicking the RMB will open the viewer options menu. Keyboard shortcuts are listed beside each entry in the menu.

Home - Re-centers and scales the image to fit in the viewer.

Display Pixel Values - Displays pixel information over the image. The Timeline should be playing forward for the values to properly update.

The following is displayed:

  • cursor uv coordinates
  • cursor xy pixel coordinates
  • RGB values 0-255
  • RGB values 0-1

Display Field Guide - Displays a 24x24 field guide over the image. The guide also displays the action safe zone and title safe zone for the image.

Display Mode - The display mode options give the option of viewing certain channels of the image.

The following display modes are available:

  • Color - Display all RGB channles.
  • Red/Green/Blue/Alpha - Display the Red/Green/Blue/Alpha channel respectively.
  • Mono - Display the image in monochrome.

Using TOPs

  • 2D image data, everything processed on GPU, generators and filters, real-time compositing
  • Import: Movie File In TOP, Video Device In TOP
  • Export: right-click menu, Movie File Out TOP, Export Movie Dialog

See also:
Mipmapping and Texture Filtering
TOP Generator Common Page and TOP Filter Common Page
Pixel Formats