Action: Control Spawning
This action will let you manage the spawning of particles. It can either spawn particles directly, or act by changing a Spawn modifier in the scene.
The Action's interface looks like this:
This sets the operation mode of the Action. There are two options:
The Action will spawn new particles directly from a source particle. It does NOT require a Spawn modifier, but it does require that you specify a spawning emitter. This mode lets you spawn new particles at a precise point without having to work indirectly through a modifier, which can be a little convoluted for a simple operation.
In this case the Action will let you control the operation of a Spawn modifier in the scene.
Control Modifier Mode
This field is only available if you choose 'Control Modifier' in the Mode setting.
This field accepts a Spawn modifier which you drag into the field from the Object Manager. Without a linked modifier, you cannot access any of the other parameters and the Action will have no effect. In addition, in the modifier's interface the Mode parameter MUST be set to 'Action-Controlled'. If it is set to 'Independent' the modifier will simply work on its own like any of the standard Cinema 4D modifiers and the Action will have no effect on it.
Effect on Particle
This drop-down menu has two modes:
Modifier Will Affect Particle
In this mode the modifier will start to influence the particular particle which is affected by this Action. Once the particle is influenced by a modifier, that influence will continue until the effect is turned off (e.g. by another Action).
Note that whether the modifier actually has any effect on the particle will depend on the modifier's parameters and especially on its falloff. Even if the modifier is set to effect a particle, it may have no effect on it if the particle never enters the field of effect of the modifier.
Modifier Will NOT Affect Particle
In this mode, the modifier's influence on the particle will be turned off and the modifier will never affect the particle, unless it is turned back on again (e.g. by another Action).
Direct Change Mode
These are the parameters which can be changed in 'Direct Spawn' mode.
In Direct Spawn mode, an emitter must be dropped into this field. Particles will be spawned from this emitter.
Add Spawning Emitter
Click this button to create a new emitter and add it to the 'Spawning Emitter' link field.
All other settings
Drag any particle group objects into this list. If there is one or more groups in the list, only those particles which are in those groups will be affected by the action. But if there are no groups, all particles will be affected by the action.