After Effects - Nulls and Parenting For Those Wayword Children

Using nulls to apply expressions can be a great way to apply a ‘hands off’ method of using expressions to direct your object while leaving the child object free. This gives you flexibility and freedom as you apply the expressions and greater control with the null object. Why not apply these same expressions to the primary object? why bring a null into the picture?

One of the best ways of viewing the use of a Null is that it gives you the ability to control/impart certain like characteristics to child objects while keeping their independence from one another. You might want them to share a path but scale differently or vice versa. Using a Null will let you do this.

I want to set up a dog chasing a cat. This is a cute animation with the animals emotions glowing, their relative size expanding with their emotions but their position is *very much* connected, the dog is chasing the Cat!

We can tie both to a Null to create this linked position while leaving them free …. to express their own emotions.

Parenting is a simple concept whose application draws explicitly from the terminology. As you design a relationship, simply ask yourself, which object drives? which object controls the flow you want to combine. Motion is an obvious application. Maybe you have an animated character riding in an automobile. Clearly the automobile drives! (forgive me). You place your character animation on a separate layer, or bring in the composition with him, and simply ‘pick whip’ the parent characteristic from the animation to the automobile.

The parent column may not be displayed by default. Within the time line panel resource columns, right click to display the columns for resources available, choose parent if it is not currently displayed.

I can’t verify ‘we reduce the Math’ using parenting but intuition would say so with fewer parameters to compute and keep up with and dependencies driving relationships, there must be some relief on our processing resources.

This can help with our hi def/avchd renderings where the sheer amount of extra information can add quite a bit to our render time and anything that contributes to the work load helps. I’ve found with my Canon vixia, using parent, expressions, and all the short cuts After Effects offers makes a real contribution to the rendering process time. There is another issue with the avchd hi def format and that is, it challenges your PC resources. Depending on your memory and processor capability, the review can appear jerky and staggered. Parenting won’t cure this but of the many resources and techniques which contribute to the consistency and fluid appearance of your composition, this is an easy one keep in your tool box.