You also have the option to write the geo to disk, so you avoid re-caching
frame before the freeze. I have been doing this with Atomkraft's AtomReadGeo
and AtomWriteGeo nodes suscesfully, by writing out Alembic files. You can use
the free version of Atomkraft for this.
________________________________
From: Torax Unga <[email protected]>
To: Nuke user discussion <[email protected]>
Sent: Thursday, 17 May 2012, 8:51
Subject: Re: [Nuke-users] Set Initial State for Particles ?
Here is a particle to geo example... action starts at frame 1000
set cut_paste_input [stack 0]
version 6.3 v6
push $cut_paste_input
ParticleEmitter {
spread 0.165
name ParticleEmitter1
selected true
xpos -164
ypos 1
}
ParticleToGeo {
align velocity
frame 1001
use_frame true
name ParticleToGeo1
selected true
xpos -164
ypos 27
}
push 0
ParticleEmitter {
inputs 2
emit_order uniformly
rate {{frame==1000?1:0 i}}
lifetime 100
name ParticleEmitter2
selected true
xpos -164
ypos 84
}
ParticleGravity {
to {0 {curve x1030 0 -0.01} 0}
name
ParticleGravity1
selected true
xpos -164
ypos 110
}
ParticleBounce {
bounceaxis_translate {0 -0.4699999988 0}
bounceaxis_uniform_scale 10
translate {0 -1.519999981 0}
name ParticleBounce1
selected true
xpos -164
ypos 148
}
________________________________
From: Paolo Berto <[email protected]>
To: Nuke user discussion <[email protected]>
Sent: Thursday, 17 May 2012, 5:17
Subject: Re: [Nuke-users] Set Initial State for Particles ?
Here's my way:
1) emit particles (set an expression or keyframes on velocity so that at a
certain frame velocity becomes 0)
in this example I am setting keyframes, you can see velocity {{curve x1 1 x20
1 x21 0}}
this reminds me to ask to Foundry to add to the ParticleCurve a "vel"
attribute as I prefer to do it there with a real curve.
2) I use a ParticleSpeedLimit to stop particles being emitted (funky way)
3) an expression on ParticleExpression sets vel = 0 after frame 20
frame>20?0:vel
4) an expression on ParticleGravity has them being affected by the field after
frame 40:
frame>40?-1:0
Have fun,
P.
#!
/Applications/Nuke6.3v7/NukeX6.3v7.app/../Nuke6.3v7.app/Contents/MacOS/Nuke6.3v7
-nx
version 6.3 v7
define_window_layout_xml {<?xml version="1.0" encoding="UTF-8"?>
<layout version="1.0">
<window x="0" y="22" w="1680" h="1024" screen="0">
<splitter orientation="1">
<split size="977"/>
<splitter orientation="1">
<split size="40"/>
<dock id="" hideTitles="1" activePageId="Toolbar.1">
<page id="Toolbar.1"/>
</dock>
<split size="933"/>
<splitter orientation="2">
<split size="1002"/>
<dock id="" activePageId="Viewer.1">
<page id="Viewer.1"/>
</dock>
</splitter>
</splitter>
<split size="699"/>
<splitter orientation="2">
<split size="587"/>
<dock id="" activePageId="Properties.1">
<page id="Properties.1"/>
</dock>
<split size="411"/>
<dock id="" activePageId="DAG.1">
<page id="DAG.1"/>
</dock>
</splitter>
</splitter>
</window>
</layout>
}
Root {
inputs 0
name /Users/poli/stop_and_run.nk
format "2048 1556 0 0 2048 1556 1 2K_Super_35(full-ap)"
proxy_type scale
proxy_format "1024 778 0 0 1024 778 1 1K_Super_35(full-ap)"
}
Viewer {
inputs 0
frame 1
input_process false
name Viewer1
xpos -853
ypos -471
}
Sphere {
inputs 0
name Sphere1
xpos -1031
ypos -609
}
push 0
ParticleEmitter {
inputs 2
lifetime 100
velocity {{curve x1 1 x20 1 x21 0}}
name ParticleEmitter1
xpos -1031
ypos -568
}
ParticleSpeedLimit {
minimum 1
maximum 0
name ParticleSpeedLimit1
xpos -1031
ypos -523
}
ParticleExpression {
velexpr frame>20?0:vel
name ParticleExpression1
xpos -1031
ypos -468
}
ParticleGravity {
to {0 {frame>40?-1:0} 0}
name ParticleGravity1
selected true
xpos -1031
ypos -411
}
Scene {
name Scene1
xpos -1117
ypos -394
}
On Thu, May 17, 2012 at 7:44 PM, Sean Brice <[email protected]> wrote:
If you want to elongate the freeze (taking place at frame 20 in that script),
you just have to change the ParticleExpression chans knob to tell it when you
want to place the particles in the 'b' channel being acted on by the downstream
forces.
>
>i.e. change the 'chans' knob to frame==30 if you want it to freeze for 10
>frames before the ParticleGravity kicks in.
>
>Cheers,
>
>Sean
>
>
>
>
>Sean Brice wrote:
>
>Hi Guys,
>>
>>Ari, if I follow you correctly you can use a combination of a ParticleDrag
>>node and a ParticleExpression node (to change the channel the particles are
>>in at a particular frame), then apply the forces to that channel downstream
>>to get what you are after.
>>
>>Have a look at this example Nuke 6.3v7 script. Is that what you want?
>>
>>Cheers,
>>
>>Sean
>>
>>
>>
>>Moritz Moeller wrote:
>>
>>On 5/17/2012 1:20 PM, Diogo Girondi wrote:
>>>
>>>A "hold" node for particles would be great.
>>>>
>>>Can't a particle expression be used to set velocity to zero?
>>>
>>>.mm
>>>_______________________________________________
>>>Nuke-users mailing list
>>>[email protected], http://forums.thefoundry.co.uk/
>>>http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
>>>
>>
>--
>Sean Brice, Product Designer
>The Foundry, 6th Floor, The Communications Building
>48 Leicester Square,
>London, WC2H 7LT, UK
>Tel: +44 (0)20 7968 6828 / Fax: +44 (0)20 7930 8906 / Web: www.thefoundry.co.uk
>
>The Foundry Visionmongers Ltd / Registered in England and Wales No: 4642027
>
>_______________________________________________
>Nuke-users mailing list
>[email protected], http://forums.thefoundry.co.uk/
>http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
>
--
paolo berto durante
space cowboy
/*jupiter jazz*/ visual research — hong kong
http://jupiter-jazz.com
_______________________________________________
Nuke-users mailing list
[email protected], http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
_______________________________________________
Nuke-users mailing list
[email protected], http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users_______________________________________________
Nuke-users mailing list
[email protected], http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
