Std DependencyGraph

Description
The Std DependencyGraph 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 a model made exclusively in the PartDesign workbench can 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 installer from the Graphviz Download page and launch it to install it. Some older versions seem to have issues displaying the graph; version 2.38 and newer are known to be reliable. You can find all graphviz releases on Gitlab.

macOS
You can install Graphviz using Homebrew if you have macOS Big Sur (11) (or higher). (While installing Homebrew, don't get nervous, if macOS asks you to install updates, e.g. for the Xcode commandline tools. These updates are performed later by the installation process.)

This installs the Graphviz binaries under /usr/local/bin for macOS on Intel, and /opt/homebrew for macOS on Apple Silicon/ARM. FreeCAD will look there all by itself. If the program is not found there you are asked to enter the path. Unfortunately we can't navigate directly there from the file dialog that comes up from. When you get the file selection dialog you have two possibilities: You can use the key combination Cmd+Shift+. which will show you all the hidden items. Or you use the keys Cmd+Shift+G to get an input field for the path. Enter in the Terminal:

or

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.

Note: If you don't have macOS Big Sur (11) (or higher) Homebrew might not work, but you can use MacPorts instead. Just download the appropriate version for your OS. Once the installation is complete, enter this command in the Terminal:

Put your password and wait while the downloading and installing of all of the computing dependencies (it can take time).

As for Homebrew the Graphviz binaries may be under /usr/local/bin or in /opt/local/bin/dot. FreeCAD may find itself the Graphviz program with the file dialog that comes up from, if not enter this command:

It will output something like:

Like previously you can tell FreeCAD to look in that directory. To enable the opt folder visible you can put this command:

then:

Therefore you can tell FreeCAD to follow this path. It has been successfully tested on macOS 10.13 (High Sierra).

Linux
On most Linux distributions (Debian/Ubuntu, Fedora, OpenSUSE), you just need to install the Graphviz package from the repositories. However, similar to the macOS, 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.

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. Alternatively  hold down the left mouse button and move the mouse.

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.