Trapcode Particular
The Layer Maps group enables the pixels of another layer to control various aspects of the particles in the field. Most Layer Map groups work with the luminance values of grayscale maps, which treat black pixels as 'off', white pixels as 'on', and gray pixels as transitional values. Note that the selected Emitter Behavior will have an impact on how a layer map is sampled. For Continuous, Explode, and Dynamic Form the particles sample the layer map at birth time (which is just frame 0 for Explode and Dynamic Form). For Classic Form, the particles are updated on every frame.
This page covers the common parameters, along with six subgroups that specify the source layer and what kind of layer map is used.
The Layer Maps Group with the Size sub-group open.
Layer pop-up: All Layer Maps have a Layer menu, which lets you specify a source from an existing layer in your composition. If you specify a source layer that contains no animation, Particular will generate a static field. If the source layer changes from frame to frame, Particular will use this information to generate an animated field.
NOTE: In general, the best results are when the size of the layer map equals the size of the particle field as defined in the Emitter controls.
Map Over pop-up: All Layer Maps have a Map Over menu. This determines the axes or manner in which you want the source layer’s values to be applied to your particle field.
Left to right, the layer map mapped over XY Plane, over XZ Plane, and over YZ Plane.
Time Span [Sec]: Controls the point at which the animation will affect the planes in Z space. This control is active for the Map Over options of XY Time=Z and XY Time=Z+Time.
Invert Map checkbox: All Layer Maps have an Invert Map checkbox. This feature saves you from having to create precomps of the same map, only inverted, in order to get the same effect.