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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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