Animation menu > Wire Parameters > Parameter Wiring dialog
Select an object. > Right-click quad menu > Transform (lower-right) quadrant > Wire Parameters > Select parameters to wire.
Select an object. > Modify panel > Right-click text box portion of animatable parameter spinner. > choose Show in Parameter Wire dialog.
Select an object with a wired parameter. > Modify panel > Right-click text box portion of wired parameter spinner. > Edit Wire
The Parameter Wiring dialog allows you to define the relationships for Wire Parameters. In this dialog, you can create new one and two-way control relationships between object parameters, edit existing relationships, and create or edit expressions which define the parameter relationships.
Only parameters that can be animated can be wired. Sub-objects, such as vertices, must be animated before they can be wired.
Parameter wires can be used to establish connections from Manipulators and Custom Attributes to objects, materials, and modifiers.
Note: The Parameter Wiring dialog is a modeless dialog, and you can have several dialogs open at the same time.
Procedures
To use an expression with wire parameters:
Create a box and a sphere in your scene.
Right-click the box, and from the quad menu choose Transform quadrant > Wire Parameters.
From the pop-up menu, choose Object (box) > Length.
Click the sphere and choose Transform > Position from the pop-up menu.
The position of the sphere and the length of the box are now wired.
In the Parameter Wiring dialog, create a one-way wire by selecting the arrow pointing towards the boxÆs Tree View.
Enter abs(position.z) in the expression text box for Box01.
Click Connect.
Move the sphere upward along the z-axis in the viewport.
Note that as the sphere moves in the viewport, the length of the box changes. Using abs() ensures that the box would never have a negative length.
To control several slave parameters from one master parameter:
Open the Parameter Wiring dialog.
Choose the master parameter in the Tree View.
Choose the first slave parameter in the other Tree View.
Click the arrow pointing towards the slave parameter.
Enter the desired relationship expression in the expression text box.
Click Connect.
Keeping the master parameter selected, choose another slave parameter from the Tree View.
Click the arrow pointing towards the slave parameter.
Enter the desired relationship expression in the expression text box.
Click Connect.
You can repeat this cycle to set up as many slaves as you want. The result is a ôfanö of parameter wires, so that you can control all of the slave parameters at once as you change the master parameter.
To create a chain of wired parameters:
Open the Parameter Wiring dialog.
Choose the first controlling parameter in one Tree View.
Choose the first slave parameter in the other Tree View.
Click the arrow pointing towards the slave parameter.
Enter the desired relationship expression in the expression text box.
Click Connect.
Keeping the original slave parameter selected, choose the next slave parameter from the Tree View.
Click the arrow pointing towards the new slave parameter.
Enter the desired relationship expression in the expression text box.
Click Connect.
You can repeat this cycle, continuing to alternate slaves to masters as many times as you like. The result is a ôdaisy chainö of parameter wires, so that as you modify the original master parameter, each slave parameter maintains a constant relationship with the next in a line of parameters.
Interface
Tree Views
There are two Tree Views, which display the animatable parameters of all of the visible objects in the scene. The names of the currently selected objects appear at the top. The Tree Views display the objects in the scene and allow you to select and wire all of the animatable parameters of the objects in the scene and the scene itself.
The Tree Views are color-coded to show existing wiring. A parameter with a wire controller assigned to it (either as the member of a two-way pair or as the slave in a one-way wire) displays in red. When a wire-controlled parameter is selected, all of the parameters wired directly to it are displayed in green text in the other Tree View. In either case, if the parameter is inside a track that is not expanded, the enclosing track will display in red or green, so you can expand the tracks to find the wires.
Note: If you open the Parameter Wiring dialog by wiring two parameters, the Tree Views will initially only display the selected objects, highlighting the parameters that were selected in the pop-up menus during the wiring procedure. If you want to expand the trees, to include all other animatable parameters in the scene, click Up To World.
There are two buttons above the Tree Views:
Show All Tracks: Brings you to the top of the scene object list.
Find Next Parameter: Finds the next wired parameter in the scene, expanding the tree if necessary to show and select it. You can browse through all existing wires by successively pressing this button.
Note: If you select a wired parameter, its connections are shown in green on the other Tree View. While the wired parameter is selected, the Show Next Wire button on the other tree will cycle through the green connections only, so you can quickly find the selected wireÆs connections.
Control Direction: There are 3 direction control buttons between the Tree Views. You can only select one of these at a time. These buttons determine the direction of control, either one-way or two-way:
Bi-directional Arrow: When this is selected, both parameters are linked, and changes to either parameter affect the other.
Left Arrow: When this is selected, the right parameter controls the left parameter.
Right Arrow: When this is selected, the left parameter controls the right parameter.
Note: You can change the direction of a wire at any time by clicking the desired direction button and clicking Connect or Update.
Connect/Update: The Connect/Update button changes its label depending on whether clicking it would add a new wire to previously unwired parameters (Connect) or change an existing wireÆs expressions or direction (Update). Changes to existing wires are only applied when you click Update.
Disconnect: The Disconnect button is enabled when youÆve selected parameters with an existing wire between them. It will remove the wire controller(s) and replace them with the Master parameterÆs animation track (if two-way) or with default controllers (if one-way).
Master parameters
The Parameter Wire system provides a way for the pair of wired parameters to be animated as a single system. It does this by setting up a sub-controller on one of the parameters and any animation on this controller drives the Wire Controller pair. The animation sub-controller is always assigned to the master parameter of the wired pair. By default, this is the parameter that is clicked on first in the wiring interaction. The master parameter can also be designated with the Master radio buttons beneath the Tree Views.
The animation sub-controller appears as a nested track inside the master parameterÆs track in Track View and its values directly drive and match the master parameter values. If the sub-controller is keyframeable (which is the default when a two-way wiring is first established) it can be keyframed by adjustments of either of the wired parameters. This means that if you keyframe the wired pair by adjusting the non-master parameter, the values keyframed into the animation sub-controller are derived from the master parameter transfer expresssion. Since the wired pair can be animated through either parameter, the choice of master parameter is essentially just a convention.
Transfer Expression boxes
Underneath the parameter trees are the transfer expression text boxes. These expressions determine how changes to each parameter affect the other and are usually inverses of one another.
The expressions use the same syntax as expressions in the expression controller.
When the parameters are first wired, the default expressions are simple 1-to-1 links between the parameters. These expressions can be edited into any valid script fragment that will yield a result of the correct type for its parameter. For example, if you link a parameter such as height (which contains a float value) to a parameter such as position (which contains a point3 value), your expressions must include conversions that produce the same output value type.
For one-way wires, the Expression box for the controlling parameter is unavailable, since there is no Wire controller assigned to it.
For two-way wiring, both transfer expression text boxes will be enabled. It is possible for the user to supply transfer expressions for the two parameters that are not inverses of one another, but this is of course discouraged, since the relationship of the parameters will be different depending on which one is changed first.