Hello, thanks a lot for your feedback!
I just tried the UserControl sample. When running the windows_x86 project I noticed a performance issue. When I click on the up/down control very I realizes, that it takes some milliseconds until my next click gets executed on the the control.
It is not a performance issue, it is a problem with the doubleclick event, when you click very fast, a doubleclick event is generated and the usercontrol is not handling it. The result is that it seems that the click is being delayed but it you focus the selector and hit space to click it very fast you will see that the performance is ok. We have fixed this issue and will be available in the upcoming final 2.1
I also realize this on the cpu performance indicator. When starting the application there is a permanent cpu consumption of about 25%
When I try the same sample on classic wpf, there is not such a performance drop.
Is this because the scene gets rendered all the time?
Yes, our examples are rendering every frame. By default vsync is on, so the CPU usage should be low (for example, right now I am testing a debug build of the UserControl sample and in my laptop I am getting around 5% of CPU usage).
Although you can render only when there are changes also in Noesis, our architecture is optimized to handle dynamic scenarios (very typical in modern videogame-like interfaces) and in those scenarios, rendering all the UI per frame is the worst case. It is not useful at all having a static UI that renders super fast in static scenarios but when you animate it, the performance drop a lot. That's not very realtime friendly.