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no it doesn't help with orientation, but it DOES
provide a much quicker way of getting paths from particles
Adrian Wyer
Fluid Pictures
----- Original Message -----
Sent: Thursday, March 30, 2006 3:46
PM
Subject: Re: How to control Particle
instance orientation?
I am not sure I follow Adrian - that provides me
with paths, but not the orientation for my fish: I'd have to manually set
paths for them all afterwards no!?
- Morten
----- Original Message -----
Sent: Thursday, March 30, 2006 4:28
PM
Subject: Re: How to control Particle
instance orientation?
enter tag point mode, tag all your particles on
the LAST frame on your animation
hit 'plot->curve'
tada!
a
Adrian Wyer
Fluid Pictures
----- Original Message -----
Sent: Thursday, March 30, 2006 3:21
PM
Subject: Re: How to control Particle
instance orientation?
Problem solved - Kim's mail sparked an idea
in my tired brain.
I tried plotting the particle motion
this morning, using Brads particle plotting tool, but there is no simple
way to control or fix the roll along a swimpath when dealing with xyz
curves :( - so I had almost abandoned that path.
Kims mail made me think it over and I just
thought of converting position curves to Path after plotting the particle
animation, and after removing rotation keyframes and activating tangency
and upvector in the Path Constraint all is good - only caveat is I have to
do that manually, but alas I can select them all and do it on a multiple
ppg. So there is a suggestion for an improvement on Brads CGS_Plot
Particles: plot to path animation with options for activating tangency and
upvector.
Thanks guys - note for Brads Sim thread on
XSIbase: we want better (read full) oriantation control for
particles!
Morten Bartholdy
3D & VFX
Artist
----- Original Message -----
Sent: Thursday, March 30, 2006 3:46
PM
Subject: RE: How to control
Particle instance orientation?
I had to deal with this a year or so ago. You're
right, the particle orientatin will flip. You're also right about
orientation being a problem with deformed particles.
My solution was to build a scripted op onto the
particles that did the orientation properly, using an up vector. It
wasn't that hard, but then it's only not hard if you have the relevant
skills.
K.
From: owner-xsi(at)Softimage.COM
[mailto:owner-xsi(at)Softimage.COM] On Behalf Of Morten
Bartholdy
Sent: 30-March-2006 14:38
To:
XSI(at)Softimage.COM
Subject: Re: How to control Particle
instance orientation?
Hi Eric,
I suppose you mean deforming the cloud to
get a swimming school of fish rather than use goals!? I guess it is
worth a try, I just see a problem with particle orientation when the
particlecloud is deformed. I don't recall if there is a script
somewhere to fix that.
Morten
----- Original Message -----
Sent: Thursday, March 30, 2006
3:00 PM
Subject: Re: How to control
Particle instance orientation?
Morton,
Have you tried deforming your cloud with a cage deformer or a
lattice instead of directly on a curve?
I usually use a lattice deformed on a curve, it appears less
rigid. Also you can get a lot of nice secondary anmation
by attaching a slow shape jitter or a wave or even animated
cluster centers on point along the curve. I am not sure what
this will do to the up vectors, but I suspect it might handle it
differently. Worth a try.
Eric
Freelance 3-D Animator, F/X Artist
----- Original Message ---- From: Morten Bartholdy
<xsi(at)colorshopvfx.dk> To: XSI(at)Softimage.COM Sent:
Thursday, March 30, 2006 3:17:19 AM Subject: Re: How to control
Particle instance orientation?
Hi Mathieu,
Yes the roll provides active control -
actually if I for instance leave the roll at 90, which
should make the fish swim on their side, they flip for every turn in
the goals path, which makes me think there is some upvector control
in play under the hood.
In my test scene I have the goal
following a path which is roughly shaped like an S. For every turn
the particles bank or roll and I have yet to find a way to avoid or
control that precisely. Actually it seems the amount of roll is not
the same for every turn. The trouble is that if I try controlling it
by keyframing the Rotation Velocity Roll, the fish in the front
rolls before the one in the back of the school, which is why I'd
rather find a sort of upvector contraint.
You can see the problem in this
movie:
Notice how the particles are actually
being orientated with something like an upvector constraint as the
goal takes effect shortly after emission, and at the right turn they
roll almost on their side. This is directly influenced by the
sharpness of the turn on the path, a bit like the orientation
problems when extruding a curveprofile on a curve.
Any hellp is much
appreciated.
Morten Bartholdy
3D & VFX
Artist
----- Original Message -----
Sent: Wednesday, March 29,
2006 5:30 PM
Subject: RE: How to control
Particle instance orientation?
Doesnt
the roll parameter from the Rotation Velocity control that? Maybe
Im misinterpreting your question but seem to me thats the control
to play with. The other way would be to create a scripted particle
event and control the orientation from a script. Im not sure if Im
being very helpful here so feel free to elaborate a bit more on
the problem if you want more
help.
Mathieu
Leclaire
R&D
Programmer
Hybride
Technologies
-----Original
Message-----
From: owner-xsi(at)Softimage.COM
[mailto:owner-xsi(at)Softimage.COM]On Behalf Of Morten
Bartholdy
Sent:
Wednesday, March 29, 2006 2:35 AM
To:
XSI(at)Softimage.COM
Subject: How to control
Particle instance orientation?
Hi
all,
I am
creating a school of fish using of instances on particles
following a goal, and it is sort of working alright. Problem is to
control the upvector of the instances - the fish roll on
their path when the goal changes direction. I have Align on
velocity on and this is working fine, the instances direction use
rotation, and face direction use rotation which I am not quite
sure has an effect on the instances, but apart from plotting and
controlling the upvector directly, is there something for
controlling the roll I have missed?
Morten
Bartholdy
3D & VFX Artist
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