This is a pretty basic lesson, but just in case you aren’t doing it already… Adding a default value to your input nodes can make your custom nodes much more useful (and possibly easier for others to use). Obviously, not every input always needs a default, but in some cases you probably know that “in 9 times out of 10 use cases, this value should be xyz”. To add this default value in Dynamo:

  1. Edit the custom node
  2. In the input node label, after the label name type a space, followed by a colon, followed by a space
  3. You are now in ‘default value land’. Dynamo will prompt you for a datatype.
  4. Choose or enter an appropriate datatype, then type a space, followed by an equals sign, followed by the default value
  5. Obviously, the value must match the datatype.

An explanatory image and a 1 minute screencast are provided below.