sj_pc

sj_pc is a small set of shaders allowing to write and read point clouds. It's provided for both Softimage and Maya (vesion 2011 and above).
It does not have all the subtleties of a real point cloud system like you could find in renderman, but it's very flexible and easy to use.
You can control the density of the cloud, and also edit it in Softimage or Maya.

Download:
Softimage
Maya


There are 3 shaders:
sj_pc_write to write the cloud to pdc or mental ray map format, or to convert from pdc to map.
sj_pc_tag to mark the objects for writing.
sj_pc_read to read the map files and interpolate the information stored in the map.

The doc:

1. Writing the cloud
2. Rendering the cloud
3. Editing the cloud
4. Examples

You can also download the Softimage examples scenes used in the doc.

For viewing and editing the clouds in Softimage, you will also need the pdc import/export plugin.