A parking flow applied to ten lots is one flow definition doing the work ten times. Knowing which values live on the flow definition and which live on each geometry tells you whether a change reaches one lot or all ten.
Properties in Giraffe usually work at two levels: usage and instance. Flows add another layer: the flow definition, shared by every geometry it's applied to, and the values each geometry keeps for itself.
Flow definition properties
The flow definition is shared by every geometry that uses the flow. It holds:
The flow graph: the nodes and wires that generate the result. Learn how a flow graph fits together in Anatomy of a Flow.
Input defaults: the default value set on each input parameter or transform node. Flow Controls shows these values until a geometry sets its own.
Default properties: values like usage and levels that a new geometry starts with when you draw it with the flow. Set these in Edit Flow Metadata and Default Properties.
Changes to the flow graph reach every geometry that uses the flow.
Applied flow properties
Each geometry with a flow applied keeps its own values, separate from the flow definition:
Input values: any input you change in Flow Controls. The value applies only to the selected geometries.
Geometry properties: the geometry's own usage, levels, and other properties. The flow reads these through its
read featurenode.
Which value a flow input uses
Each flow input uses the geometry's own value first, then falls back to the flow definition.
The geometry has… | The flow uses… |
Its own value for the input, set in Flow Controls | The geometry's value |
No value for the input | The input default from the flow definition |
To go back to the flow definition's value, hover the input in Flow Controls and click Revert to default (the back-arrow icon). This clears the geometry's own value.
What a change reaches
Change | Reaches |
Edit the flow graph | Every geometry using the flow |
Change an input default in the flow graph | Every geometry using the flow that has no value of its own for that input |
Change an input in Flow Controls | Only the selected geometries |
Change the flow's default properties | Only geometries drawn with the flow from then on |
Change a geometry's usage or other properties | Only that geometry |
Default properties are copied onto a geometry once, when you draw it with the flow. Applying a flow to an existing geometry from the Select a flow dropdown doesn't add them, and it clears any input values left from the previous flow.
Save a geometry's inputs as the flow's defaults
When one geometry's inputs are right for every geometry, save them to the flow definition. Right-click the geometry, then choose Flow > Save as input defaults. Every geometry using the flow that has no value of its own picks up the new defaults.
Give some geometries their own flow definition
To change the flow graph for only some geometries, duplicate the flow, edit the copy, and apply the copy to those geometries.