Each SOP has a list of Points. Each point has
- an XYZ 3D position value.
- other optional standard attributes like RGB color, alpha, texture UV and W, Normal XYZ.
- user-defined attributes.
Each polygon is defined by a vertex list, which is a list of point numbers.
On s SOP, MMB on the node to see a summary of the points, polygons and other primitives, attributes and bounding box.