General

With the Field Driver tag, object and tag parameters can be defined spatially using Fields.

Originally, Fields were used to spatially control a few properties (e.g., position, angle, color, etc.) of MoGraph clones with the help of effectors.

Wouldn't it make sense to apply this spatial control to other areas outside of MoGraph?

In the further development of Cinema 4D, the field functionality was therefore extended to other areas: e.g., deformers, volumes, vertex maps, force Fields etc.

As of Cinema 4D 2025, Fields can now also control any object or tag parameters within definable limits.

Field Driver tags are always assigned to the objects whose object or tag parameters are to be controlled!

Example 1

In this example, the intensity and color of spotlights are controlled by a linear or Spherical Field. Please note that the Field Driver also affects cloned objects.

Example 2

Here, slipping textile (Cloth tag) comes to a standstill by increasing the friction by means of a Linear Field.

Application

Proceed in the same way if you want to control a parameter using a Field Driver tag:

Right-click on an Attribute Manager parameter and call up Field Driver / Add. If no Field Driver tag is available, one is generated with the corresponding parameter. The parameter clicked on the right is stored in the Parameter tab together with the Min. and Max. settings . If several Field Driver tags are assigned to the object, the parameter ends up in the first Field Driver. Or:
Drag and drop a parameter from the Attribute Manager onto an associated, existing Field Driver tag. The parameter is stored in the Parameter tab together with the Min. and Max. settings . Or:
Assign a Field Driver tag to the object (Animation tag/Field Driver). Click on the Add parameter button in the Parameters tab. All object or tag parameters from which a corresponding one can be selected are listed.

If you want to free a controlled parameter again, proceed as follows:

Right-click on a controlled parameter and call up Field driver / Remove from the context menu. Or:
Right-click on a controlling parameter in the Parameter tab in the Field Driver and call up Field driver / Remove from the context menu.

Other interesting facts about the Field Driver tag

Some GUI elements such as function graphs/splines/curves (described on this page) or text input Fields cannot be controlled with the Field Driver tag, but they can:
GUI elements such as selection menus or options (menu options are numbered internally and options are activated from 50% field value and deactivated below 50%). However, the menu option sequence is occasionally unpredictable for internal reasons.
Field modifiers such as Push Apart and Delay result in corresponding temporal effects in parameter control.
Please also note that the Field Driver tag can be used to conveniently control Pose Morph tags.