Consider an instance of a geometric model of a wind sock, which is to be rotated depending on the wind direction; that is, whenever the wind changes, the <Geometry Model Instance> is rotated accordingly.
The <Rotation> of the applicable <LSR Transformation> controlled by a <Rotation Control Link>, which is driven using values from a <Property Table>. That is, the <Rotation Control Link> is driven by a <Predefined Function>, SE_PREDEF_FUNC_TABLE_VALUE, containing a <Property Table Reference> referring to the <Property Table> containing the rotation values.
The wind sock rotates around the Y axis, depending on wind speed. (That is, if the wind speed is zero, it will hang down toward the ground, while if the wind speed is higher, it will straighten out parallel to the ground).
The <Property Table> is classified as ECC_CONTROL_VALUE, and has a <Table Property Description> specified by SE_VAR_CODE_ROTATION_ANGLE. The <Property Table> specifies, for each EAC_WIND_SPEED value, the angle to which the wind sock should be rotated.
Consider a <Translation Control Link> instance that is to be driven using values from a <Property Table>. The table values that are to be used are to be cycled through 8 times, with each cycle taking 10 seconds. This sequence of cycles is to be triggered from outside the transmittal.
The <Translation Control Link>'s controlling <Expression> is a <Predefined Function> instance for SE_PREDEF_FUNC_TABLE_VALUE, whose argument is a <Property Table Reference> instance referring to the <Property Table> containing the translation values.
Note that the <Table Property Description> for the control values and the <Variable> instance controlling the referencing expression have the same meaning = { SE_ELEM_CODE_TYP_VARIABLE, { SE_VAR_CODE_TRANSLATION_AMOUNT }}
The <Property Table Reference Control Link> controls which value is referenced from the <Property Table>, and is itself driven by the SE_PREDEF_FUNC_CYCLE_TIME <Predefined Function>. The cycle length (10 seconds) and the number of cycles (8) are specified as arguments to the function.
The <Variable> drives the <Property Table Reference Control Link> through the <Predefined Function>, so that it determines which value is referenced from the <Property Table>. To provide the hook for this <Variable> to be set from outside the transmittal, the <Variable> is associated with an <Interface Template> (not shown).
If this <Translation Control Link> appears inside a <Model>, then to set the <Variable> using another variable from outside the transmittal, the data provider merely has to have the <Geometry Model Instance> supply a <Variable> from its own context for the value of the <Model>'s <Variable>.