The following rules are applied by the program when the Mass Model Generator tool is used to create equivalent mass loads from gravity loads.

1. Only vertical load components are considered out of the selected loads.

   Typically, these are loads parallel to the global Y direction. In the case of Z Up, these are loads parallel to the global Z direction.

2. Only the user selected loads are considered, regardless of load item types and directions included in all load cases.
3. Only load items in global or projected directions are considered. Any load item in the local direction (typically those labeled X, Y, or Z; e.g., uniform member loads in local coordinate directions) are ignored.
   Note: Selfweight loads are by default applied in the global X, Y, and Z directions. So the vertical selfweight loads are considered.
4. Moment component of loads are ignored for generating equivalent gravity loads.
5. Repeat and reference loads are expanded into a set of internal loads and the rules are then recursively applied to these.
6. Additionally, some load types are ignored as they are not applicable to mass models. Please see the following table for additional details by load item category and load item type.