Hi Adrian,
thanks for the explanation of your approach. Yes, that sounds like a lot
of work.
I was thinking more along the lines of asking Autodesk to implement
additional cache editing as a feature,
e.g. be able to retime and reanimate existing cached data as if working
with a keyframed channel.
Either using an animation curve on the time input or even messing with
the full data with interpolation
between "keyframes", knowing that motionblur will then still work nicely.
I would think this could be regarded desireable for working with alembic
files, bifrost, volumes, particles, animation, etc.
There is a standalone app that let´s you modify particle caches after
sim, I can´t remember the name atm...
Anyway, asking to get Trax have better interpolation for caches might be
interesting, too.
Imho, having to decide beforehand how many subsamples/ticks/substeps to
store in a cache is a bit of a shot in the dark
and can easily bloat files while still not solving the problem of always
getting nice motionblur, regardless of shutter
settings and lengths that may change later.
I´d think there is room for improvement, ideally allowing to cache to
sparse data and interpolate for best results.
Am 19.02.2015 um 01:41 schrieb Adrian Graham:
I've written scripts that do this:
- generate a null for each particle emitted
- move the null to the updated particle location on each frame
- keyframe the null after moving it
- rinse and repeat
So you end up with a big mess of nulls and keyframes, and not much else you do
with them.
I suppose you could do the above, then kill particle emission, then do it the
other way around; write a runtime expression to emit one particle per null, and
move it where each null is at each frame. This would work at any sub-frame, as
the runtime expression would query the exact position of the associated null at
the current time.
But that's a real roundabout way of doing this, and you'd quickly bog down with
hundreds or thousands of particles/nulls.
If you're really interested in doing this, I could try it and record a video
showing you how I did it.
Adrian
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Tim Leydecker
Sent: Wednesday, February 18, 2015 3:59 PM
To: [email protected]
Subject: Re: OT Maya: ncache hell
Hi Adrian,
would there be a way to plot/bake an nCache to keyframes per particle and then use the
"natural" interpolation happening between keyframes to get better retiming
results?
One could then always re-export to a new cache?
If not, that may be an idea to suggest as a feature request?
E.g. the feature request would be to allow the user to edit any cached data
input in the fcurve editor as keyframe data with all the interpolation options
usually found between two keyframes.
That shouldn´t be insanely complicate to be pulled off as it would "just"
require to read cache data as keyframes, then interpolate instead of step, no?
Cheers,
tim
Am 18.02.2015 um 20:05 schrieb Adrian Graham:
Er, let's pretend you guys never saw that...
From: Ben Beckett <[email protected]<mailto:[email protected]>>
Reply-To:
"[email protected]<mailto:[email protected]
m>"
<[email protected]<mailto:[email protected]
m>>
Date: Wednesday, February 18, 2015 at 5:19 AM
To:
"[email protected]<mailto:[email protected]
m>"
<[email protected]<mailto:[email protected]
m>>
Subject: Re: Aw: OT Maya: ncache hell
Maya 2016!
On 18 February 2015 at 04:23, Adrian Graham
<[email protected]<mailto:[email protected]>> wrote:
Hey guys, the best way to retime nCaches is in the Trax editor. Select the
cached node and open the editor. You'll see a bar representing the length of
your cache on disk. You can expand/compress this bar to achieve the retiming
you desire. You can't ramp-in/ramp-out the speed, unfortunately. Not without
extremely unpredictable results, that is.
Now it gets tricky, so I recorded a couple of videos (in .swf format) to maybe
provide a bit of insight:
nCache_retiming_01.swf<https://autodesk.box.com/s/ves0ye66ny9sc0y78a8c
k8xi8af2zyns>
nCache_retiming_02.swf<https://autodesk.box.com/s/bxwfnuupxw11fz9tvfr9
4k72djb9fwfv>
Also, as I mentioned at the end of the second video, a suggestion from one of
our devs here is to goal 'classic' particles to your nParticles
(post-retiming), cache those out and render them, rather than the nParticles:
You could export it as a classic particle cache (with dynExport) , and then
create a classic particle shape with exactly the same set of attributes as you
exported. (which means that you either have to explicitly specify the list of
PP attrs so that you don't end up with ramp input attrs, or you may need to add
any extra cached attrs to the classic particle system).
Hope this helps,
Adrian
From:
[email protected]<mailto:softimage-bounces@listp
roc.autodesk.com>
[mailto:[email protected]<mailto:softimage-bounc
[email protected]>] On Behalf Of Gerbrand Nel
Sent: Monday, February 16, 2015 4:59 AM
To:
[email protected]<mailto:[email protected]
Subject: Re: Aw: OT Maya: ncache hell
Ugh....
Well thanks for the heads-up.
G
On 16/02/2015 11:50, Leo Quensel wrote:
I've been through this hell.
Long story short: Do it in Softimage, it is next to impossible to do it
properly in Maya and it is a buggy mess.
Gesendet: Montag, 16. Februar 2015 um 10:45 Uhr
Von: "Gerbrand Nel"
<[email protected]<mailto:[email protected]>><mailto:[email protected]
<mailto:[email protected]>>
An:
[email protected]<mailto:[email protected]
<mailto:[email protected]<mailto:[email protected]
odesk.com>>
Betreff: OT Maya: ncache hell
Hey guys
So I have to re-time my particles in Maya, and no one seems to know
how to do this properly.
Do you guys know if I can bring them into softimage, re-time, and then
re-export the ncache to maya?
Even if you know how to do it with houdini, please shout!
Thanks guys
