Working with Particles - Mastering Blender - page 336

Number Number determines the total number of particles that will be emitted over the course of the particle
system's duration.
Start Start sets the start frame for emission.
End End sets the end frame for emission. The number of particles set in the Amount field will be entirely
emitted between the start and end frames.
Lifetime Lifetime determines the number offrames forwhich each particle will persist between the time it is
emitted (birth) and the time it disappears (death).
Random Random sets the range around the Life value in which the life span of each particle can vary ran-
domly. A Rand value of 0 will constrain all particles to last exactly as long as the Life value.
All of these values taken together influence the density of the particles. The density of the particle system
often plays an important part in creating a convincing effect, so it is important to be aware of this. For example,
if youincrease the number offrames that yourparticle system is active forwithout changing the Amount value,
the resulting particle output will be sparser.
Emit From Values
The Emit From button values—Faces, Verts, and Volume—determine how the particles emit from their emitter
mesh. The buttons enable you to select where on the mesh the particles emit from.
Faces By default the Emit From button is set to Faces, so emitter particles will emerge from the normals of
the mesh's faces.
Verts When Verts is selected, particles emit from the mesh's vertices.
Volume InthecaseofVolume,theparticles originate frompointswithinthemesh,andtheshapeofthemesh
is filled with particles positioned on the grid. This can be useful when you do not need the shape of the mesh
itself to play as much of a role in the particles' emission—for example, in explosions.
Random Settings
The Random check box controls whether particles are released from the mesh in a set order or whether the or-
dering is randomized. For example, if 800 particles are set to be emitted from a cube's vertices, 100 particles
will be released from each of the cube's 8 vertices, in a fixed order, if Random is unchecked.
Even Distribution Settings
The Even Distribution check box sets the emission of the particles to be calculated based on the size of faces
and the lengths of edges in order to yield a more uniform distribution.
Distribution choices are Jittered, Random, and Grid. These enable you to choose how the particles are ar-
ranged with respect to the surface they are emitting from.
Jittered The default value is Jittered, which means that the particles are slightly offset from points subdivid-
ing the surface they are emitting from. The degree to which they are offset depends on the Amount value in
the field directly below the menu.
Random Random creates a patternless distribution of emission points over the surface.
Grid The Grid option creates a three-dimensional, volumetric grid in the bounding box area of the Mesh ob-
ject, with a resolution of the value in the Resol field. When this option is selected, the Number value for the