2009

The box emitter is mapped with a gradient. With Position Object set to Density By
Material > Grayscale, the particles appear with greater frequency in the lighter
areas of the box.
■ Opacity Particles are more likely to appear on opaque areas than on
transparent areas.
■ Grayscale & Opacity Combines the two: More particles appear on light,
opaque areas than on dark, transparent areas.
■ Red/Green/Blue Considers only the specified color channel. The higher
its value at any given pixel, the more likely particles are to appear there.
Use Sub-Material When on, uses a sub-material from the Multi/Sub-Object
material assigned to the emitter to define density values.
This option allows usage of “invisible” materials for particle placement. If the
emitter uses a Multi/Sub-Object material but its geometry doesn't use the ID
Particle Flow | 2859