Return-Path: Received: from mail-vw0-f41.google.com ([209.85.212.41] verified) by media-motion.tv (CommuniGate Pro SMTP 4.2.10) with ESMTP-TLS id 4581706 for AE-List@media-motion.tv; Fri, 06 Jan 2012 19:07:54 +0100 Received: by vbbfn1 with SMTP id fn1so1374200vbb.28 for ; Fri, 06 Jan 2012 10:14:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=So2OnfSkQpXtnfr/ffGehMilPufBr4t40y7wZ1Q4PyQ=; b=nUUmCauz2jGdKpuG/pLaYjLeoJg6n04mk6FV5/pCa+djQ2GT2wGvNcgPUJqPbdlXiU dK4aBobp9REIm9dUJaFbIp7HK4BPzTaof3jOzuMIPVpv25KlUKDXt5zHWn4Gdy2v2kc8 XWtnzKP7O5RQqDGxKNPY1wv25F0/QJej6SAtU= MIME-Version: 1.0 Received: by 10.52.64.228 with SMTP id r4mr3631042vds.36.1325873677431; Fri, 06 Jan 2012 10:14:37 -0800 (PST) Received: by 10.220.64.195 with HTTP; Fri, 6 Jan 2012 10:14:37 -0800 (PST) In-Reply-To: References: Date: Fri, 6 Jan 2012 10:14:37 -0800 Message-ID: Subject: Re: [AE] Attention Expression Gurus From: Darby Edelen To: After Effects Mail List Content-Type: multipart/alternative; boundary=20cf30780c9a8f727f04b5e0059e --20cf30780c9a8f727f04b5e0059e Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Dan's expression works great but I often parent my "emitter" null to another null for more complex animations. In any case where the "emitter" Null is parented you'll have to use an expression that doesn't rely on the position property of the Null but rather the rate of change of its absolute world position. Altering Dan's expression this would be: minSpeed =3D 0; maxSpeed =3D 500; minParticles =3D 10; maxParticles =3D 1000; n =3D thisComp.layer("Null 1"); f =3D thisComp.frameDuration; p1 =3D n.toWorld(n.anchorPoint); p2 =3D n.toWorld(n.anchorPoint, time + f); s =3D length(p2 - p1) / f; linear(s, minSpeed, maxSpeed, minParticles, maxParticles); Here's an animation preset that will apply Particular with the required expressions, as well as some expression controls to allow artists to change the variables of the expression on a per-layer basis: http://dl.dropbox.com/u/1950339/SpeedEmit_Particular.ffx This animation preset uses some error catching to avoid problems if the artist does not have an "emitter" null selected. -D On Thu, Jan 5, 2012 at 7:03 PM, Dan Ebberts wrote: > There=92s more than one way to do it, but something like this should wo= rk: > > minSpeed =3D 0; > maxSpeed =3D 500; > minParticles =3D 10; > maxParticles =3D 1000; > N =3D thisComp.layer("Null 1"); > > linear(N.transform.position.speed,minSpeed,maxSpeed,minParticles,maxParti= cles) > > > Dan > > *From:* Chris Biggs > *Sent:* Thursday, January 05, 2012 6:51 PM > *To:* After Effects Mail List > *Subject:* [AE] Attention Expression Gurus > > I'm working on a project that requires a Base comp be built that all the > artists can use. > it's a Trapcode particular effect that needs to add to amount for > particles emitted depending apon > velocity of the emitter ( using a null to drive the emitter) > i.e. moving slower less particles, faster more particles. > > any suggestions ? > > Thanks > Chris > -- > --------------------------------------- > R.Christopher Biggs > Digital Ronin > --20cf30780c9a8f727f04b5e0059e Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Dan's expression works great but I often parent my "emitter" = null to another null for more complex animations.=A0 In any case where the = "emitter" Null is parented you'll have to use an expression t= hat doesn't rely on the position property of the Null but rather the ra= te of change of its absolute world position.=A0 Altering Dan's expressi= on this would be:

minSpeed =3D 0;
maxSpeed =3D 500;
minParticles =3D 10;
maxParticles =3D 1000;
n =3D thisComp.layer("Null 1");<= br>f =3D thisComp.frameDuration;

p1 =3D n.toWorld(n.anchorPoint);p2 =3D n.toWorld(n.anchorPoint, time + f);
s =3D length(p2 - p1) / f;linear(s, minSpeed, maxSpeed, minParticles, maxParticles);

Here's an animation preset that will apply Particular with th= e required expressions, as well as some expression controls to allow artist= s to change the variables of the expression on a per-layer basis:

http:/= /dl.dropbox.com/u/1950339/SpeedEmit_Particular.ffx

This animatio= n preset uses some error catching to avoid problems if the artist does not = have an "emitter" null selected.

-D


On Thu, Jan 5, 2012 at 7:03 PM= , Dan Ebberts <debberts@comcast.net> wrote:
There=92s more than one way to do it, but something like this should= =20 work:
=A0
minSpeed =3D 0;
maxSpeed =3D 500;
minParticles =3D 10;
maxParticles =3D 1000;
N =3D thisComp.layer("Null 1");
linear(N.transform.position.speed,minSpeed,maxSpeed,minParticles,maxPa= rticles)
=A0
=A0
Dan
=A0
Sent: Thursday, January 05, 2012 6:51 PM
Subject: [AE] Attention Expression Gurus
=A0
I&= #39;m=20 working on a project that requires a Base comp be built that all the artist= s can=20 use.=20
it's a Trapcode particular effect that needs to add to amount for = particles=20 emitted depending apon
velocity of the emitter ( using a null to drive the emitter)
i.e. moving slower less particles, faster more particles.
=A0
any suggestions ?
=A0
Thanks
Chris
--
---------------------------------------
R.Christo= pher=20 Biggs
Digital Ronin

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