question: protected void redraw ( ) { Date modelTime = model . getTime ( ) ; if ( Math . abs ( modelTime . getTime ( ) - lastUpdateTimeMs ) > UPDATE_FREQUENCY_MS ) { lastUpdateTimeMs = modelTime . getTime ( ) ; RaDec sunPosition = SolarPositionCalculator . getSolarPosition ( modelTime ) ; rendererLock . lock ( ) ; try { renderer . queueEnableSkyGradient ( GeocentricCoordinates . getInstance ( sunPosition ) ) ; } finally { rendererLock . unlock ( ) ; } } }
target:  Redraws the sky shading gradient using the model's current time. 