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Dillon
02-07-2017, 05:34 PM
So I've discovered (rediscovered) the limitations of HV after starting to play with them again. Motion blur doesn't work. I tried using Vector blur, but vector blur only works when the camera is moving, not on moving particles.

Anyone have any recommendations on how to render out a particle cloud (sprites) and be able to apply a motion blur to them? I'm willing to do the particles in a separate pass (think rain on a city).

Thanks,

Dillon

erikals
02-07-2017, 06:18 PM
works fine, see settings

jwiede
02-07-2017, 07:08 PM
Erikals, IIRC, if you're setting it to use a number of passes, then it implicitly isn't the "new" PRMB, it's the old-style motion blur.

Dodgy
02-07-2017, 08:14 PM
Jweide, both the old style and photoreal can use the MB passes, as an alternative to using more AA passes. HV's always use the classic pass method though, instead of stochastic time sampling.

Dodgy
02-07-2017, 08:17 PM
Here's a poly torus and a null HV with PR motion blur set to 5 samples and no AA

jwiede
02-07-2017, 09:03 PM
Jweide, both the old style and photoreal can use the MB passes, as an alternative to using more AA passes. HV's always use the classic pass method though, instead of stochastic time sampling.

Ah, okay, is that new? For some reason, I recall it used to be that activating passes disabled PRMB, and only used normal/dithered MB. In any case, good to know.

@Erikals: Wouldn't you want "particle blur" turned on the in the HV test? If not, then when _is_ the right time to enable particle blur (if not when using pfx/HVs)?

erikals
02-08-2017, 03:14 AM
@Erikals: Wouldn't you want "particle blur" turned on the in the HV test? If not, then when _is_ the right time to enable particle blur (if not when using pfx/HVs)?
i'm actually not sure. :hey: it doesn't make a difference with sprites, but maybe it makes a difference in volume or surface mode...
edit: no, just tested, particle blur doesn't need to be on, i remember it used to, back in the days. not sure what difference it makes in 11.6 and beyond.

Dodgy
02-08-2017, 03:20 AM
Particle blur is only for 1 point poly blurring, and was originally added for Babylon 5 stars which were one point polys, but is also useful for 1 point particle emitters.

erikals
02-08-2017, 03:35 AM
aah... cool info!    http://forums.cgsociety.org/images/smilies/arteest.gif

Dillon
02-08-2017, 11:17 AM
Thanks, everyone. You're all correct, HV will indeed render with motion blur passes turned on.

I must have found a bug ... is anyone able to verify (and/or suggest a workaround?) - it seems that motion blur won't be applied to HV particles that are in a scene containing instanced geometry.

I just tested this out. The scene I was trying to get my HV sprites to render out with motion blur, none would be applied, no matter what setting I chose for motion blur.

Then I start with a cleared scene and "load from scene" only the particles, and motion blur works.

Instancing seems to kill motion blur for HV particles? That's an odd bug...

I'll test this out a couple more ways to confirm (or deny) this.

Thanks again everyone.

Dillon
02-08-2017, 12:26 PM
Nope, wasn't instances. Not sure what happened. Something in the particle emitter I'd set up got fudged.

Rebuilt the scene from scratch, and now it renders as expected. Weird.




Thanks, everyone. You're all correct, HV will indeed render with motion blur passes turned on.

I must have found a bug ... is anyone able to verify (and/or suggest a workaround?) - it seems that motion blur won't be applied to HV particles that are in a scene containing instanced geometry.

I just tested this out. The scene I was trying to get my HV sprites to render out with motion blur, none would be applied, no matter what setting I chose for motion blur.

Then I start with a cleared scene and "load from scene" only the particles, and motion blur works.

Instancing seems to kill motion blur for HV particles? That's an odd bug...

I'll test this out a couple more ways to confirm (or deny) this.

Thanks again everyone.

shrox
02-08-2017, 02:41 PM
This post belongs here now!

http://forums.newtek.com/showthread.php?152482-Cautionary-and-Bizarre-Tales-of-Lightwave-3D!

Dillon
02-08-2017, 03:19 PM
Argh, it's back. HV will no longer render with motion blur. This is after I tweaked the particle birth rate and particle count to much higher numbers. HV no longer motion blurs.

Setting the count and birth rate back to their lower number, and the particles will render with motion blur again.

Definitely a bug :(


This post belongs here now!

http://forums.newtek.com/showthread.php?152482-Cautionary-and-Bizarre-Tales-of-Lightwave-3D!