int32 HandleVariableRead ( int32 ParameterMapIndex, const [FPin](API\Plugins\NiagaraEditor\TNiagaraParameterMapHistoryBuild-\FPin) * InPin, bool RegisterReadsAsVariables, const [FInputPin](API\Plugins\NiagaraEditor\TNiagaraParameterMapHistoryBuild-\FInputPin) * InDefaultPin, bool bFilterForCompilation, bool & OutUsedDefault )