Properties
When a parameter is selected in the parameters list, a number of options are available to the right of the list.
The Name text box lets you specify a name for the parameter. This value may be empty, if you do not wish the parameter to have a label in the host’s UI.
The Properties popup button lets you specify a number of options:
The ID option (which cannot be changed or edited from this menu) represents an internal value used by all hosts to uniquely identify the parameter. This ID is also used by FxFactory to save and retrieve parameter values from presets. The parameter ID can be edited in the parameters list.
The Animatable via keyframes option lets you decide whether the user should be allowed to animate the parameter via keyframes. This option is available only if the parameter expresses values that may be animated.
The Display in parameter inspector option lets you control whether the parameter appears inside the parameter inspector of all supported video applications.
The visibility of a parameter can be further determined by per-host settings (read below for more information) and via dynamic parameter UI.
Per-host visibility is based on the video application that is hosting your plug-in, and not on the underlying library used by the video application to load the plug-in. This remark will sound confusing until you remember that Final Cut Pro X, Motion 5 and Compressor all use a common “Motion engine” to render effects.
Although dynamic UI settings can override the initial visibility of a parameter, it is important to notice that dynamic UI settings cannot override per-host settings. For example, if the option …and in After Effects is disabled, the parameter will never be available in After Effects whether or not the dyamic UI conditions are met.
The …and in Motion's HUD option lets you designate the parameter to be displayed both in the parameter inspector and in a separate overlay window, the HUD. Motion is the only host that sports a HUD window. Only certain parameter types, such as sliders, angles and popup menus, can be displayed in the HUD.
The Display on-screen option lets you control whether the parameter will be available as an on-screen controls in all supported hosts1). Point parameters are displayed on-screen by default. This option cannot be turned on for parameters that cannot be displayed on-screen.
An additional option can be turned on for toggle parameters that are visible on-screen. Enable the …and make it toggle point parameter visibility property to make the parameter control the visibility of all on-screen point controls. This particular behavior can help design attractive UI based on point parameters that control user interface drawn in the Quartz composition2).
Another option available only for toggle parameters is Toggles visibility of all on-screen parameters. It gives the user a chance to disable all the on-screen controls published by a plug-in. This includes point parameters as well as the controls available at the bottom of the Canvas window.
The Save value with project option lets you decide whether the value of the parameter is saved along with the Motion, Final Cut Pro or Final Cut Express project where the plug-in is used. If a parameter value is not saved along with the project, it will default to its original value every time the project is re-opened.
The Save value to presets options lets you decide whether the value of the parameter is saved to presets files created via a Presets parameter.
Sometimes, it will make sense for a parameter not to be saved to the project. For instance, your plug-in may contain a “Setup Mode” which the user can turn on to aid in the effect configuration.
More often, it will make sense for certain parameters not to be saved to presets. For example, you may want to exclude timing parameters from presets (any parameters that control an animation’s progress). This allows the user to explore different “looks” without having to worry about the animation being switched to the wrong timing.
The Save value to presets option also has a side effect. It doesn't just control whether a parameter is saved to a preset. It also controls whether a value read from presets is actually applied. This allows the behavior of a plug-in to be refined even after the first release has shipped.
Suppose, for example, that in the initial revisions of your plug-in you forgot to disable this option for certain parameters. This would mean that a value was in fact saved to preset files.
Later on, when you realize your mistake, you can still disable this option to exclude the parameter from being saved to (or read from) presets.
Mappings
Below the Properties popup menu you may find one or two additional popup menus. These popup menus allow you to map the value represented by the parameter to one or two inputs of your Quartz compositions.
The parameters you create in FxFactory may require one or more mappings to published input or output ports in the Quartz composition. Most parameters (such as sliders, angles) only require one mapping. Point controls require two mappings, since they feed X and Y coordinates to the Quartz composition; Parameter groups and Banner Image parameters require no mappings; Image Well parameters have one mandatory and one optional mapping, and so on.