A custom helper icon is a mesh exported to a custom format that can be used with an OgreMax Dummy helper object.
Custom helper icons can be three-dimensional or two-dimensional. In either case, only the visible edges of a mesh will be exported. An example of a two-dimensional mesh:
The custom helper icon exporter is a standard 3DS Max exporter that can be found within the 3DS Max export dialog, accessible through the File menu:
Once the export dialog has appeared, if necessary, look for the Save as Type labeled OgreMax Custom Helper Icon (*.CHI).
Enter a file name and press the Save button.