Hi Helge ,
I received the same results when testing , I am sure there is a reason I am just not sure what it is. Ill have to think on it for a bit and test a bit more.
i tried a very simple model in SWX. just a rectangle block no specific size. the part itself had about 50kB
put this into visualize and added a rotation animation about Y at 4500 for 5 sec.
first render: motion blur deactivated - GPU at 95%
second render: motion blur activated - GPU dropped to 65% lows and 85% highs
model size seems to influence the story but i think the root cause is somewhere else
looking forward to your testing results
Hi Helge - from what I remember, the majority of the "work" involved in rendering a scene with motion blur is in the translation of the geometry (jittering), not in the rendering itself. Therefore it is not a GPU intensive task. The result is that the GPU has to do relatively little work when rendering a scene with motion blur compared to a scene where no motion blur is involved. This is also why rendering with motion blur takes longer.
I hope this helps de-mystify the scenario.
thanks for de-mystifying this
it certainly apears to be the reason, all be it not very satifying. I was planing to do a animation sequenz of about 20sec in which motion blur would need to be activated.
i finished the 1000 passes in the above test file and ended up with 10min for one frame vs 1:30min. this would sum up to 20sec x 30fps x 10min = 100h render time. if i then put the rest of the Model into the scene the render time is bumped to 23min one frame.
Maybe the Software Gurus at SWX can find a way to optimze this ;-)
Putting your answer as correct