Return-Path: Received: from mail-ey0-f169.google.com ([209.85.215.169] verified) by media-motion.tv (CommuniGate Pro SMTP 4.2.10) with ESMTP-TLS id 4581808 for AE-List@media-motion.tv; Fri, 06 Jan 2012 21:37:47 +0100 Received: by eabm6 with SMTP id m6so1254186eab.28 for ; Fri, 06 Jan 2012 12:44:32 -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=Ik0KSFyX8oQZbIWg6r0hMd3zP7Pn//upN8zNH0hbMMg=; b=rhvlCh7xdgzhjE1lXojx72GMTZtezl6SRorNQFK9vmu0fhT01lAxNUocfmI9dNOh5I qi1Vmf2k+zgEwSfVj5lbMzcSOM0hEApJBkZcL5qedMlc5TuxsBUJPeJLncTfAFZP4vjM GCpwPvSN+fKUQgZ6GUzMrLGD5cXx9j/CKWskw= MIME-Version: 1.0 Received: by 10.205.120.138 with SMTP id fy10mr3184069bkc.109.1325882671954; Fri, 06 Jan 2012 12:44:31 -0800 (PST) Received: by 10.204.15.130 with HTTP; Fri, 6 Jan 2012 12:44:31 -0800 (PST) In-Reply-To: References: Date: Fri, 6 Jan 2012 12:44:31 -0800 Message-ID: Subject: Re: [AE] Attention Expression Gurus From: Chris Biggs To: After Effects Mail List Content-Type: multipart/alternative; boundary=00151743f842acfa6c04b5e21dae --00151743f842acfa6c04b5e21dae Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Thanks I'll give it a try Chris On Fri, Jan 6, 2012 at 10:14 AM, Darby Edelen wrote: > 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 th= e > position property of the Null but rather the rate of change of its absolu= te > 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 chan= ge > 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 >> work: >> >> 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,maxPart= icles) >> >> >> 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 >> > > --=20 --------------------------------------- R.Christopher Biggs Digital Ronin --00151743f842acfa6c04b5e21dae Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Thanks I'll give it a try

Chris

On Fri, Jan 6, 2012 at 10:14 AM, Darby Edelen <dedelen@gmail.com> wrote:
Dan's expression works great but I often= parent my "emitter" null to another null for more complex animat= ions.=A0 In any case where the "emitter" Null is parented you'= ;ll have to use an expression that doesn't rely on the position propert= y of the Null but rather the rate of change of its absolute world position.= =A0 Altering Dan's expression this would be:

minSpeed =3D 0;<= /div>
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.anchorPoin= t);
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 animation preset uses some error catching to avoid problems if th= e artist does not have an "emitter" null selected.

-D



On Thu, Jan 5, 2012 at 7:03 PM, Dan Ebberts <de= bberts@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'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




--
= ---------------------------------------
R.Christopher Biggs
Digital R= onin
--00151743f842acfa6c04b5e21dae--