The Particles Falloff

This is an additional falloff for the X-Particles particle modifiers.

Note: this falloff may not work correctly other than with the X-Particle modifiers; for example, it may not do anything in Cinema 4D deformers or Mograph effectors. This is currently a limitation.

Most falloffs use a defined area for the falloff, such as the volume of a cube or sphere. The particle falloff, however, treats each particle from an emitter as its own individual falloff. This allows a modifier to affect particles only when they are within the required distance of a particle from another emitter.

Interface

The falloff appears in the Falloff tab of any object in Cinema which can use falloffs. To use it, select 'xpParticlesFalloff' from the 'Shape' drop-down menu in the Falloff tab. The available settings are shown here:

Parameters

Radius

This is the sphere surrounding each particle from the falloff emitter within which the modifier will have an effect on other particles. The strength of the effect is determined by how close the particles are. For example, if the 'Radius' is set to 10 units, and the distance between two particles is 9 units, the strength of the effect is multiplied by 0.1 (1.0 - distance/radius is the actual formula used, in this case that is 1.0 - 9/10). The closer the particles, the stronger the effect, up to 100% strength.

A particle may be within the 'Radius' distance of more than one particle from the falloff emitter. In this case, the strongest possible effect is the one used (i.e. the closest of all possible particles from the falloff emitter).

Show Radius

Check this box for a visual representation of the radius value around each particle from the falloff emitter.

Emitter

Drag the emitter which is to be the source of the falloff particles in here.

Groups

In X-Particles 4, the Particles Falloff now supports particle groups. If there are no groups in this list, all particles from the emitter are used. Otherwise, the falloff will return zero for all particles not in one of the groups in the list.