Know the Basics: Maya Part 5: Animation
In part five of the Know the Basics: Maya 2017 series, Paul Hatton delves into the world of animating...
Step 01: An intro to key frames
Animation can be crudely defined as 'objects which move over time'. They essentially have a starting point and an end point and then they move between the two. Think of the beginning and end points as key frames. Everything in between (time) can be thought of as frames. We are going to learn how to define key frames and then tell Maya how to interpolate the motion between those frames.
Step 02: Key frame Object Animation
As a further introduction we need to be aware that once we've created an object we need to know how to animate it. That animation could involve the changing of object attributes over time or the transformation of objects or skeletons. Key frame animation is particularly pertinent when animating characters because if you were to set a character's position every frame, it would end up looking forced and unnatural.
Step 03: Starting with simple keys
If we head over to the Attribute Editor then we'll see displayed a set of attributes which can not only be edited but which can also be animated over time. Setting a key frame for an attribute is as simple as moving to a point in time (using your range slider) and then right-clicking on the attribute followed by 'Set Key'. Setting keys in this way gives you absolute control over how and when key frames are created.
Step 04: Making it automated
An alternative to setting key frames manually is to use something called 'Auto Key'. This will basically place key frames whenever you change the current time and any associated attribute values. With 'Auto Key' turned on inside the Range Slider, go to a point in time and set a key frame like in step 2. Then navigate to another point in time and adjust that same attribute. You'll notice that Maya creates a new key frame.
Step 05: Editing keys
Assuming that you're not the perfect animator that never makes a mistake, you'll want to be able to edit the keys that you create. Some of the most common tasks involve copying, pasting, cutting and deleting keys. You can perform all these operations by right clicking on a key and selecting the action that you want. If you prefer shortcut keys then you can find those in the help documentation.
Step 06: A little more theory
You may have realised that Maya is making decisions about how to interpolate the object's attributes between the key frames. If we simplify the theory there are two options for how Maya calculates the interpolation. The first way is that it calculates it in a linear fashion. This means that the attributes are adjusted equal amounts every frame until it reaches the next key frame. The more advanced option is to use a curve to dictate each frame's adjustment over time. Let's look at that now.
Step 07: Graph Editor
To avoid the interpolation being linear we need to use something called the 'Graph Editor'. To open the 'Graph Editor' simply go to 'Windows' -> Animation Editors' -> 'Graph Editor'. With it open you'll notice that there are two axis to the graph. The horizontal axis represents your time and the vertical axis represents the values of your selected attributes. The key frames you've already created are shown on the graph and are connected together by a curve. Each key frame includes tangents which define the interpolated curve.
Step 08: Adjusting the curve
As discussed in the previous step use the tangents to affect the curve. Simply dragging them around will give you a good idea of how they affect the curve. Note that the steeper the curve becomes the quicker that your attributes will change and conversely the gentler the curve the longer it will take for your attributes to change. By creating custom curves you gain absolute control over how your object changes over time.
Step 09: Add keys to the curve
At times you'll want to be able to add keys directly into the curve inside the Graphic Editor. Do this using the 'Insert Keys' tool found on toolbar. Simply click on the curve to add the key. With the key successfully inserted you can then adjust its settings. To delete any keys from the curve simply right click on the desired key and select 'Edit' followed by 'Delete'.
Step 10: Path Animation
An alternative way to animate your objects is to let a curve define the movement. By doing this you can help to ensure that your objects move in a predictable and natural manner. This is particularly helpful for moving cameras through your scene. We don't have time to cover the process but you can find a step by step process in the Maya help section. I just wanted to let you know that it was possible!
Top tip: Making your motion natural
To create nice and believable motion you'll want to make sure that things are physically believable. Aspects such as weight and speed play a large part on how the object will slow down or stop. Using this information will help you fine tune the animation and make it more believable.
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Know the Basics: Maya Part 1: Interface
Know the Basics: Maya Part 2: Viewports and Navigation
Know the Basics: Maya Part 3: Modelling
Know the Basics: Maya Part 4: Organisation