A particle can be rendered in many ways. The geometry to be used at rendering
time is given by GEO_PART_TYPE and is stored in a GEO_PartRender object within
the particle system itself.
Here are the predefined geometry types a particle can be rendered as:
The geometry type is not the only rendering parameter available to you. The
Class GEO_PartRender contains a host of methods that control other rendering
attributes such as particle size and motion blur:
Here is an example of how to build a particle system with 4 particles rendered
as rounded tubes and motion blurred. We also define a particle drag factor of
one: