Std DependencyGraph

Description
The Std ExportGraphviz command displays the dependencies between objects in the active document in a 'dependency graph'. As opposed to the Tree view, objects are listed in reverse chronological order, with the first created object at the bottom.

It can be useful in analyzing a FreeCAD document and locating forks in a tree. The dependency graph layout will depend on which workbench was used to create the objects in the document. For example, in FreeCAD 0.16, a model exclusively made in the PartDesign workbench should display a linear dependency graph with a single vertical branch. A model made with Part operations will have many branches, but for a single part they will join up at the top after Boolean operations. If they don't, it means that they are separate objects.

The dependency graph is purely a visualization tool, therefore it cannot be edited. It automatically updates if changes are made to the model.



Installation
To use the command a third-party software named Graphviz needs to be installed. If you do not have it pre-installed or it is installed in an unconventional location, FreeCAD will display the following dialog:



Windows
Download the graphviz-2.xx.msi installer from the Graphviz Download page and launch it to install it.

Mac/OSX
You can install graphviz using Homebrew:

This installs the graphviz binaries under /usr/local/bin. Unfortunately we can't navigate directly there from the file dialog that comes up from. When you get the file selection dialog use the keys Cmd+Shift+G to get an input field for the path. Enter

and confirm the input field and the file selection dialog.

In case the Graphviz binaries are installed in a non-standard location try to find the program with the command

It will output something like

And therefore you can tell FreeCAD to look in that directory.

Linux
On most Linux distributions (Debian/Ubuntu, Fedora, OpenSUSE), you just need to install the graphviz package from the repositories. However, similarly to Mac/OSX, in cases where the Graphviz binaries are installed in a non-standard location, try to find the program with the command:

It may output something like

And therefore you can point FreeCAD to look in that directory.

Configuration
You shouldn't need any configuration of FreeCAD preferences. If FreeCAD cannot find the utility 'dot' (from the Graphviz package) then a dialog comes up and asks the user for its path: set the path to the folder that contains the 'dot' executable, do not select the executable itself. FreeCAD then tries to start the utility again and in case it succeeds the value is written automatically to the user parameters.

Usage

 * 1) Select the  option from the menu.
 * 2) A new tab titled Dependency graph opens in the Main view area.
 * 3) Use the mouse scroll wheel to zoom in or out.
 * 4) Use the sliders at the bottom and at the right of the screen to pan the view.

Save
You can save a dependency graph:
 * 1) Make sure the Dependency graph tab is in the foreground.
 * 2) Select the  or  option from the menu.
 * 3) Enter a filename and select the file type (*.png, *.bmp, *.gif, *.jpg, *.svg or *.pdf).
 * 4) Press the  button.

General principles

 * The graph shows objects in reverse chronological order.
 * The direction of arrows showing dependencies should always point down, from the child object to the parent object. An arrow pointing up indicates a cyclic dependency, an issue that needs to be resolved.
 * A sketch that contains links to external geometry will have a number with an 'x' suffix besides the arrow linking it to its parent, showing the number of external geometries linked in the sketch.
 * Objects can have dependencies to multiple parents. For example, for a model built in PartDesign, a Pocket may be linked to its Sketch and to the Pad feature that came before it.
 * Disallowed dependencies (for example, between a Draft/Part operation and an element inside a PartDesign Body) will show with a red arrow. This type of link usually shows a 'Links go out of allowed scope' error in the Report view.
 * A Part container and PartDesign Body enclose their content inside a frame with a randomly colored background. Their Origin also encloses its content (standard planes and axes) in a frame.
 * A Groups is displayed as a single element linked to its content.

Limitations

 * The dependency graph cannot help with the topological naming problem. If a sketch switches faces of a feature after an edit, it is still linked to the feature. Even if some features are broken, the dependency graph will remain unchanged.