Maya Training

Creating characters In Maya and Zbrush

Maya Training

Creating character renders in Maya 2017 and Arnold

Maya Training

Spach-Alspaugh House the complete courseware
You are here > Home > SimplyMaya Community Forums

Welcome to Simply Maya

Please Sign in or Sign up for an account

Member Login

Lost your password?

Not a member yet? Sign Up!

Old 27-11-2003, 02:40 AM   #1
Registered User
Join Date: Nov 2003
Location: Washington, USA
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Default important question with expression editor

Once again this has to do with the matrix tutorial on highend3d.

I dont understand this:

Select particleshape1 and open the expression editor.Add the runtime expression


Play the animtion and you will find that each particles are now instancing a random letter and changes every frame. It is now near the effect we want. But we still need to write some expressions to control the motion of each particle.

Select particleshape1 and add one another array attribute "gate". It has not much meaning , just for used in the expression. Add the runtime expressions below to the particleshape1.

vector $temp=particleShape1.worldVelocity;
if ($temp.y<=rand(-10,-5))
{ particleShape1.gate=1;};
if ($temp.y>=(-1))

if (particleShape1.gate==1){ particleShape1.acceleration=<<0,rand(20,25),0>>;
if (particleShape1.gate==0) {

You can find the tutorial in this place to see the whole thing, any help would be greatly appreciated;


P.S. If someone could tell me where I could find a better or more clear explanation of how to do this, please tell me! Thanks again!
Jay_R_Locke is offline   Reply With Quote
Old 28-11-2003, 02:50 PM   #2
Alan's Avatar
Join Date: Oct 2002
Location: London, UK
Posts: 2,800
Thanks: 0
Thanked 5 Times in 5 Posts

Select particleshape1 and open the expression editor.Add the runtime expression
select the particleShape1 in the ouliner. Then Go to the expression editor it's in window>>animation editors>>expression editor

Then you should find a value called index (I'm not sure if adding it is part of the tutorial earlier on). then type in the expression editor the equation it says in the tutorial and select "runtime expression" as the type of expression. This simply means that it will be calculated as the render is run.

To add an attribute to the particle system select it in the outliner then go down to per particle attributes and add it on. YOu can then add that next expression in the same way as you added the first.

Technical Director - Framestore

Currently working on: Your Highness

Alan is offline   Reply With Quote

A little bit about who we are
Links you might find useful
Catch up with SimplyMaya
SimplyMaya specialises in Maya tutorials. We offer over 1,000 individual Maya training videos, ranging from basic Maya tutorials through to intermediate Maya tutorials. Our tutorials are created by instructors with industry experience and are designed to get you up and running in Maya quickly without making it seem like hard work.

Copyright © 1999-2017 SimplyMaya - vBulletin® Copyright © 2000-2017, Jelsoft Enterprises Ltd.