PostworkShop has 5 different pin colors that correspond to 5 different kinds of connections.

  • White: Image pins
  • Blue: Palette pins
  • Yellow: Curves pins
  • Green: Stroke pins
  • Purple: Vectorial pins (which are generally used as stroke directions)

In the Style Editor, each filter shows which pins can be connected to it. On the sides of the filters, you can see the edges in different colors: most of them are white/white, but some specific ones show the number and type of input pins (e.g.: Simple strokes, Simple Watercolor, Tone Mapping, etc...) 

 

A few consideration about the filters and pins: 

Any kind of pin can be connected only to a pin of the same color.
An Input pin can only receive only one input connection. But, from one Output pin, there can be as many output connections as you want.
Nodes can have any number of input and output pins.
Generators do not have input pins but you will not find any of these nodes without at least one output pin.

If a node has more than one input pin, the first one is always the primary input pin that must be connected. This is usually an image input pin, but not always. The other pins on the node do not need to be connected. The pin type does not matter, since the second input pin can also be an image input pin, but the connection still remains optional, because it is a secondary pin, not the primary one. In other words, except for the primary input pin (which is required), connecting the other pins is optional. The node will work fine without those other connections, but will use its default values for the pins that are not connected to any other nodes.
The Result Filter is able to add new input pins to itself dynamically.

In the example above:

•    From the Image Source Output pin (white), there are 3 output connections, but each Input pin has only one incoming connection.
•    “Simple Strokes” has 4 Input pins but only 3 are connected: 1 Palette pin (blue), 1 Stroke Pin (purple) and an Image Input (white).
•    The Palette Generator’s blue Output pin is connected to a blue Palette Input pin on “Simple Strokes”.
•    The Curve’s yellow Output pin is connected to a yellow Input pin on the “Tone Mapping” filter.
•    The "Stroke Direction” filter has a purple Vectorial Output pin which is connected to the “Simple Strokes’” Input pin.
•    The “Edge Detector” Output pin is connected to the green Input pin of the "Curved Strokes" Input pin.