Parenting is a simple concept in 3d that is as widely used as it is unspoken of in articles about 3d animation, and by parenting, I don’t mean raising your offspring in a healthy and responsible fashion (you’d need more than a one thousand word article for that!). The Parenting I’m talking about is the technique that allows us to do anything from equipping our characters with handheld props to allowing separate animated rigs to adhere to the same set of animated transformation, rotation or scale channels.
In this article, we’ll look at some of the problems parenting can solve in creating 3d animated shorts or skits. While I’ll be demonstrating use cases in Blender, this process is applicable to 3ds Max, Maya, Cinema 4d, Modo or almost any other 3d creation suite out there! It’s even used in 2d animation software like Adobe After Effects.
This article will touch on scenarios that may be overwhelming to the beginning 3d filmmaker. Still, it’s my belief that being aware of these cases will make clear the importance of parenting and prove useful later on.
For the uninitiated, the concept of Parenting can be illustrated in this simple example:
In this scene, we have a small plate and let’s imagine we would like to add a couple of doughnuts to this plate.
ShaZAM! After some masterful 3d modelling, we now have our doughnuts sitting nicely on the plate.
At the moment, as indicated by our location coordinates, our snacks are positioned at the centre of our 3d world. We will inevitably want to move this on top of a table or on a character’s lap at some point. We could do that by simply repositioning everything to a new location, but what if we had 100 doughnuts meticulously arranged on the plate? Selecting each doughnut and the plate AND THEN moving them would be a disaster for our mental well being!
Wouldn’t it be great if we could move just one of these objects and have the rest follow suit?
That’s where Parenting comes in.
In this screenshot, we have the doughnuts nested within our plate object. The plate acts as the parent of these doughnuts now.
We can now move, rotate, and scale our Plate-Parent, and the doughnuts also inherit the transforms.
If we wanted to adjust the positioning of the children of a parent (doughnuts), we could still do so without affecting the plate.
We can define Parenting as a means of nesting objects within other objects so that the host object’s transforms are inherited by the nested objects, but not vice versa.
A more complicated example of parenting is a rig.
This entire rig is built from individual bones parented to each other in a hierarchy. That makes it possible to, for instance, rotate a shoulder bone to move the whole arm, then adjust the position and rotation of the elbow, wrist and fingers accordingly after.
At the very core of an animated character is a hierarchy of parent and children bones, and they are what allows us to bring these 3d characters to life!
In Blender, objects can be parented to each other from within the outliner or using the hotkey Ctrl + P. In 3ds Max or other software, I suspect the method is similar or at least just as simple.
These days we can get by without having to create rigs ourselves (thank heavens), but there are always situations where our understanding of Parenting will come in handy.
If you’re making a 3d animated short, it’s likely that short will involve a character or two interacting with objects. In this example, a staff is parented to the hand-bone of the character’s rig but is set not to not be visible. A visible duplicate of the staff is on the ground. As the character makes the grab, the staff on the ground is animated to not be visible, while the parented staff, which was invisible up to this point, is now shown. This simple use of parented objects made the task of getting the character to pick up the staff ridiculously easy to accomplish.
Non-Linear Animation is a feature that can be found in Blender, Maya and Cinema 4d (as well as other 3d software, I’m sure). It allows us to mix and match animation clips that were made on duplicates of the same rig.
Whether using motion capture or pre animated clips on your character, you may find yourself having to work with two animations that move in different forward directions. If you wanted to make them move in a single direction, adjusting the actual animation data would be a pain. Instead, you can parent one of the rigs to a new object, rotate that object to align the child rig to its counterpart, and apply the new transform data. Doing this will instantly reorient the rig and make it possible to then combine its animation with its counterpart’s.
In some cases you may have two animated meshes that need to move in concert. In this example, I have a character on horseback. The character has some subtle animation to show some weight distribution as a consequence of the moving horse. The horse has a walk cycle animation in place. The character’s rig is parented to one of the center bones of the horse, which drives the character’s up and down direction in response to the horse’s movement.
The horse rig is moved forward by a curve, and since the character inherits the transformation of the horse, she moves along with it naturally.
And that wraps up this little number on the virtues and utility of Parenting in the creation of 3d animated shorts. I hope this was useful to you, and that the examples described here will be of help to you at some point in your journey. Thanks for reading!
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