01 - General


SCRATCH is a nodal based system and in using SCRATCH you will encounter many different node types:

  • Media nodes, like dpx, ARRI or H264 shots.
  • Output nodes for rendering new media in a specific format.
  • Collector-, Stereo- or Nest-nodes to wrap other node sequentially, in a certain pattern or to force a colorspace transformation or group certain grades.
  • Plug-in nodes for rendering specific effects such as adding text, paint strokes, lens flares, etc. SCRATCH comes with a series of plug-ins of its own but it also supports the OpenFX plug-in interface which makes it possible to use many third party effect plug-ins.

Each of these node types has its own settings which are available from the Node menu in the Matrix. Please be aware that the label of the menu button in the Matrix will reflect the current active node type and a such can change while browsing your timeline or composite tree. Details on the available settings for each node type are discussed later in this chapter.

    Furthermore, keep in mind that certain node types (like e.g. dpx Media nodes) do not require any additional settings for loading the media. In that case the Node menu is empty, except for displaying the shot type name and underlying media path. 


    Most effect nodes require one or more inputs to process the effect. In the Input menu in the Matrix you can manage the inputs of a node. The menu layout is the same for any node type and provides you with a thumbnail list of all inputs required for the shot. For media nodes the Input list will be empty though as there is no separate input shot - just the underlying media. However, more complex plug-ins may require multiple inputs, such as a separate Background or Matte input. In these cases you can use the Inputs menu to load separate shots into each required input.

    You can use the FETCH option in the Matrix to select a shot that can serve as input. To remove a shot from an input and revert back to the default, click on the Clear button. Once loaded, you have several controls that can be used to determine how the shot is applied.

    Note: When instantiating an effect plug-in on a layer, the node might not have an explicit input assigned. In that case the layer-input is implicitly the input for the effect node.


    The Slip control allows you to offset the relationship between the current base frame and the frame being used for the input. You can use the Frame Slip to align the timing of several shots so that all elements are synchronized.


    The Length control determines how many frames from the source shot will be used. You can use the Length control in conjunction with Slip and the Loop mode to specify how a shot will behave when applied as an input.


    The Loop mode controls the behavior of a clip if there are fewer frames than the base shot. There are three options: Repeat, Loop and Bounce.


    The Repeat mode holds the last frame of the sequence for the remaining duration of the base shot.


    The Loop mode jump back to the first frame of the sequence, and continues looping the entire sequence for the remaining duration of the base shot.


    The Bounce mode alternates between forward and backward playback of the sequence for the duration of the shot.

    For example, if you have a base shot that is 100 frames long, and you load a shot for a Background input, and set that input’s length to 25 frames, the Loop mode will determine what frame is used from frames 26 to 100.

    If the Loop mode is set to Repeat, frame 25 of the input shot will be held for the remaining 74 frames of the base shot. Loop mode plays the same 25 frames over in the same order. Bounce mode plays the shot forward for the first 25 frames; then reverses for 25 frames; then forwards for 25 frames; and then reverses for 25 frames.


    Activating the Color Grade button will apply the current color grade to the input shot.

    Posted - Saturday, May 30, 2020 2:19:09 PM