Quote Originally Posted by dognzhe View Post
1. "First get rid of "ensure visible" functionality ", I need it to keep it in viewport, sence is much big than viewport. any other way?
Scroll the viewport yourself. QGraphicsView is derived from QAbstractScrollArea.

2."If you set the period of the timer to 40ms (which gives you 25fps) your performance will improve (you can compensate for the distance to have a similar impression of "speed").
"
I tried, in order to get same speed i have to move tank 15 pixels very timer which makes tank move serious blurry
So find something in between.

3 ." if you really need GraphicsView for this use case, maybe it only slows you down."
any they other way?
Yes, QWidget

4. "don't allocate QImage objects on the heap, it doesn't make sense to do so. "
what should i use? bitmap?
No. You should learn reading the docs and at least a bit of C++. Now go google for "heap" and read QImage docs.