mwindow->playback_3d->copy_from(this, refresh_frame, output_frame, 0);
lock_canvas(" Canvas::output_refresh");
get_canvas()->lock_window(" Canvas::output_refresh");
mwindow->playback_3d->copy_from(this, refresh_frame, output_frame, 0);
lock_canvas(" Canvas::output_refresh");
get_canvas()->lock_window(" Canvas::output_refresh");