The value is the @uID of the referenced element, exactly as given in its @uID attribute, e.g. the @uID of the wing to which an engine pylon is attached. Any number of references can point to the same element.
References to symmetric components
A component with a @symmetry attribute, e.g. a wing with symmetry="x-z-plane", results in two components: the component described by its data (defined side) and its mirror image (mirrored side), which is a component of its own. The @symmetry attribute of a reference to such a component selects the side that is meant:
| Value | Referenced part of the component |
def | defined side only |
symm | mirrored side only |
full | both sides, i.e. the defined and the mirrored component (default) |
The attribute is only used in references to components with a @symmetry attribute.
The figure shows an engine pylon whose <parentUID> references the main wing, mirrored at the x-z plane. With def, the pylon belongs to the defined side of the wing only, with symm to the mirrored side only, and with full to both sides.
<enginePylon uID="pylon">
<parentUID symmetry="symm">mainWing</parentUID>
...
</enginePylon>Side appended to the uID in older datasets
Older datasets often append the side to the referenced @uID instead, e.g. mainWing_symm for the mirrored side of the wing mainWing or engine1_def for the defined side of engine1. This is not intended and must not be used: the string does not match the @uID of the referenced element. Reference the @uID unchanged and select the side with the @symmetry attribute, as in the example above.
<enginePylon uID="pylon">
<parentUID>mainWing_symm</parentUID>
...
</enginePylon>