Introduction to CHOPs Vid Notes

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Importing the image and making adjustments[edit]

Setting Up The Switch TOP[edit]

  • The Switch TOP will now have four inputs. The initial image unedited and the three adjusted images each with their own hue offset. You can test this by seeing if the colors change when you click the Switch TOP and then drag the Index parameter slider to the right. The number in the index parameter represents the inputs number. For example the first input is the image with a hue offset of -25 since the last image that was wired in was the unedited image with no hue offset.
  • Set the Switch TOPs image parameter to 4. The image in the Switch TOPs viewer should now be the same as the image in the Level TOPs viewer.
  • Turn the Blend Inputs check box in the Switch TOP on.

Setting CHOPs to drive parameters[edit]

  • Double click above the TOPs in your network and whilst holding shift under the CHOPs tab select a LFO CHOP and then releasing shift select a Math CHOP.
  • CHOPs are generators and filters. Generators create data, a numerical value changing over time where as filters modify that data. For example take a look at the LFO CHOPs viewer. The LFO CHOP is a changing number (sine wave) which moves from -1 to 1 and then back again. The frequency (how quickly the value changes) can be edited within the parameters of the CHOP. Set the Frequency parameter to 0.5. It's also worth noting that in the OP Create Dialog generators are a darker green than filters.
  • In order to animate the color of the butterflies you can use the newly created CHOP channel (generated in the LFO CHOP and then manipulated using the Math CHOP) to be the numerical value in our Switch TOP parameter. The problem is that the numerical value in the LFO CHOP is only -1 to 1 whereas the numerical value needed for the Switch TOP is 0 to 4.
  • Click the Math CHOP and under the range tab you will see a From and To parameter. This parameter will allow you to change the channels value from -1 to 1 and then to 0 to 4 which would fit the Index parameter of the Switch TOP. Set the From parameter as -1 to 1 and the To parameter to 0 to 4.
  • To export this value to the TOP first right click the output of the Math CHOP and select a Null CHOP.
  • Activate the viewer of the Null CHOP and drag and drop the channel to the Switch TOPs Index parameter until a small plus icon with an arrow appears then let go. Select Export CHOP from the pop-up menu that appears. The parameter should now be blue and constantly changing value.
  • The butterfly in the Switch TOPs viewer should now be changing color smoothly.

Overlaying the butterfly onto a black background[edit]

Switching between manual and automatic[edit]

Creating a Button COMP to switch between manual and automatic[edit]

  • Double click the network above the Switch CHOP and whilst holding shift, select under the COMP tab a Button COMP and then releasing shift switch to the CHOP tab and select a Null CHOP.
  • Right click the Null CHOP and export this Null CHOP too but rather than to the Switch TOP export it to the Switch CHOP instead.
  • Zoom out of the network until you are viewing Project1. Under the Layout tab on Project1 change the Width to 400 and the Height to 400.
  • At the top left of the screen above the network editor there is a small ^ icon. Click it to go into Perform Mode. Press the Escape key to close Perform Mode. As you press the button the butterfly will change color and then stop when the button is pressed again.

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.

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 which operate on Channels (a series of numbers) which are used for animation, audio, mathematics, simulation, logic, UI construction, and many other applications.

(1) The TouchDesigner window is made of a menu bar at the top, a Timeline at the bottom, plus one of a choice of Layouts in the middle. A Layout is made on one or more Panes, each Pane can contain a Network Editor, Viewer, Panel, etc. See Pane and Bookmark. (2) Nodes in a network are arranged using Layout commands in the RMB menu.