solved 10-15% Performance hit with blurred rotors/mast in VR

[edmuss]

In VR there is currently a significant performance loss associated with the blurred effect on the rotor blades/mast when they reach operating speed.  I see a repeatable 10fps loss that corresponds directly with the rotor switching to the 3D modelled (no blur) to the blurred appearance.  Slowing the rotors so that the appearance changes again restores the performance loss.

Attached are two tracks comparing a cold start between BS2 and BS3.  The blurred effect is not present on BS2 and does not suffer the performance hit at operating rotor speed.  The blurred effect is not present on the Hind and similarly doesn't exhibit the loss, I believe that the blurred effect is present on the Apache so it should be easy enough to correlate the typical effect.

As the blurred effect is largely invisible in the cockpit, please can it be made a tickbox option (either special option or general) to disable it?  Every frame counts in VR and to lose 10-15% for something that is invisible seems silly when the whole range of high to low graphics settings results in the same sort of performance delta.

I will try to get a video capture to demonstrate the issue, other people have witnessed the same as well.  I have tried all variations of resolution, graphics options, overclocked/stock GPU, updated GPU drivers, disabled mods & cleared shaders.  System is as per signature.  I run MT exclusively and admittedly I haven't tested it on ST but I suspect it will behave in the same manner.

edit: Have captured the video showing the performance drop, you can clearly see the immediate step in the graph when the rotors blur at around 7 seconds, I then stop the autostart and the graph steps up when the rotors unblur at around 32 seconds.

Also note that the FPS jumps up when the rotors are not in view as I look down at the fuel shutoffs and then drops down again as I look up at the cockpit.  With the engines off, looking up in the cockpit gives around 85-90 fps so it's not the outside scenery that drops it.

BS3_high_speed_rotor_blade_performance.trk BS2_high_speed_rotor_blade_performance.trk

Edited June 7, 2023 by edmuss

[edmuss]

In the latest update, this appears to be fixed.  No longer seem to have any major fps drop once the rotors are at full speed
@BIGNEWY can you confirm if this is the case officially or has it been fixed in along with something else?