I was able to reproduce your issue and have created a task to fix this. In short, when chart data is drawn out of range, the Raster target ends up interpreting this as a "no data" condition and clears the render area.
As a workaround, you can change RenderMode to Vector; or you can use a custom data source that disables chart optimization, such as the collection below that derives from the data source used in the example:
[DataTypeDescriptor( typeof( GraphDataCollectionDescriptor<> ) )]
public class CustomChartCollection : ChartCollection<double> {
public CustomChartCollection( ) : base( 100000 ) { }
protected override void OnDataChanged( GraphCollectionChangedEventArgs e ) {
base.OnDataChanged( new GraphCollectionChangedEventArgs( 0 ) );
}
}
~ Paul H
