ShiveringCactus has some quick new videos in their Just the Tip series. These videos teache Expressions and more in After Effects. Be sure to subscribe to their channel to keep on top of their latest releases.

### Just the tip: Linking CC Particle World to a 3D Null in After Effects

First, the tutorial. Below, I’ll paste the expressions:

Expressions:

Position X:

x=thisComp.layer(“Null 1”).transform.position[0]-thisComp.width/2;

x/thisComp.width;

Position Y:

y=thisComp.layer(“Null 1”).transform.position[1]-thisComp.height/2;

y/thisComp.width;

Position Z:

z=thisComp.layer(“Null 1”).transform.position[2];

z/thisComp.width;

## Just the tip: Using expressions to roll a ball or sphere in After Effects

He explains that in this tutorial, an expression is used to calculate how much a circle or image should rotate. To clarify, this is established by its horizontal position. If you want to roll 3D objects, his expression gives that option.

Expressions:

2D Layer

diameter=width;

pi=Math.PI;

circumference=diameter*pi;

rot=360/circumference;

Xpos=thisLayer.transform.position[0];

scalePercent=thisLayer.transform.scale[0]/100;

rot*Xpos/scalePercent

CC Sphere in one dimension:

diameter=effect(“CC Sphere”)(“Radius”)

pi=Math.PI;

circumference=diameter*pi;

rot=360/circumference;

Xpos=thisLayer.transform.position[0];

scalePercent=thisLayer.transform.scale[0]/100;

rot*Xpos/scalePercent

CC Sphere coming towards camera:

diameter=effect(“CC Sphere”)(“Radius”)

pi=Math.PI;

circumference=diameter*pi;

rot=360/circumference;

Xpos=thisLayer.transform.position[0];

scalePercent=thisLayer.transform.scale[0]/100;

rot*Xpos/scalePercent*-1

At the moment he has 3 tutorials out in the Just the Tip series. It looks like he’s doing about 1 per month. Great stuff!

## More Expressions Tutorials

#### Create a Mograph Style Effect in After Effects featuring Expressions

Joey from School of Motion walks you through how to make a spinning mograph animation. It’s reminiscent of something that could be made in Cinema 4D. This tutorial utilizes a lot of expressions so get ready to learn! If you’re a student, register for an account at the School of Motion, and then, download the project files.

#### Visualizing Music and Animating to Audio in After Effects: Tutorials and Plug-ins

Animating to the beat can be a tedious job if you do it by hand. Luckily, there’s no need to do it by hand! There are plug-ins to help you with the task. We’ve also got a couple of tutorials that show you some other techniques. In fact, they include free files, such as scripts and templates.

#### 3 Free Scripts for After Effects

Today it’s Freebie Friday so we’re featuring 3 Free Scripts for After Effects that we know you will find to be useful additions to your toolbox.