improved motion blur
#1
ive not had very good results so far with getting nice motion blur on tyflow particles.. as i understand it currently tyflow only provides 2 samples for moblur irrespective of the number of subframe steps calculated.  

this means straight lines for all moblur, which does not look very nice. 

i also get the impression sometimes the motion vectors are not correct (the blur seems go in a slightly different direction to the motion, but that could be either the 2 sample blur or my imagination.. 

is it anywhere in the to-do list, or are there any work-arounds?
  Reply
#2
You haven't say what render you're using.
I have no complains on how vray handles Tyflow MB.
(with exception that I like to see Tymesher have a proper MB)

Anyway, depends on particle setup, and what you want but one of the workaround (if the particles are small (like sparks)), is that you can spawn few particles, after each particle, and make a sort of small trail.
That way, if particles have swirling curvature motion, you could see a nice trails, additionally blurred with MB.
  Reply
#3
(12-10-2020, 02:24 PM)d4rk3lf Wrote: You haven't say what render you're using.
I have no complains on how vray handles Tyflow MB.
(with exception that I like to see Tymesher have a proper MB)

Anyway, depends on particle setup, and what you want  but one of the workaround (if the particles are small (like sparks)), is that you can spawn few particles, after each particle, and make a sort of small trail.
That way, if particles have swirling curvature motion, you could see a nice trails, additionally blurred with MB.

hi, i am using vray, with instanced low res spheres as the geometry.   i have 4 sub-steps, and 10's of millions of particles.     project is spray coming off spinning tyres in the rain.   even with 4, or 8 geometry samples in the motion blur settings, i get only perfectly straight motion blur trails from the droplets.   given that their trajectory curves significantly over the course of a frame, this makes things look a bit rubbish. 

if i am missing a setting somewhere and curved moblur is poissible id love to know what im doing wrong! 

its a nice idea to spawn a trail behind each particle, but im already at 5-6 hrs sim time, and 12 hrs to render a still, with 70 gb ram use.   adding a trail to each of the particles would kill my machine i expect!  -i might be able to use this method on the flow for the larger drips closer to the tyre, of which there are many less.
  Reply
#4
Wow - 5-6 hours sim time.
I've never had such a big sims, never waited more then 40 minutes.
However, majority of my animations are just simple tests, so no wonder.

Did you used PhysX, or Particle Physics, or none of it, or just made particles from fluid sim (fume or phoenix)?
I ask that, because, maybe there is a way to optimize them (and maybe spawn trails like I suggested)
There is an Upres in official sample files, and the basic idea is that you create fewer particles, and just spawn more to follow their path (with spread operator, that will... well... spread them Big Grin ).
That way you might be able to achieve huge optimization, and have enough memory to spawn some trails.

how do you turn on the motion blur?
All I do is just turning it in the camera - nothing else.
But yeah, I think it won't work on more samples then 2.

Another idea is to export velocity pass, and there is a great After Effects plugin Real Smart Motion Blur, and you can do MB in post.
Look pretty good actually, and You'll have better control.

Sorry I can't be of better help, maybe someone with more experience and better idea will hop in, and help.
  Reply
#5
I have to concur that proper subframe moblur is the biggest wish I have for TyFlow. The ability to get things like curved embers, rotating fragments or other things with highly irregular/arching motion to blur in a proper fashion and not perfectly straight would be extremely helpful with getting more photorealistic results for VFX.  I know there are tricks and workarounds in most cases, but it would be great if it just worked.
  Reply


Forum Jump: