Timeline FX: Animation

Uploaded by SmokeHowTos on 11.06.2012

In the previous video, we went through the axis basics and how to use the timeline FX.
In this video, we will focus on animation as well as the animation editors in Autodesk Smoke.
The first thing you need to know about animation, is that you create animation in two modes.
The first mode is using auto key that automatically animates the affected values as you work.
The second mode is working with auto key set to off, where you have to manually set keyframes to animate parameters.
Animated parameters inherit an animation channel, which can be adjusted numerically or gesturally, in the animation editor.
A parameter’s numeric value box is called a slider, since you can modify a value, by simply clicking on it,
and dragging the mouse left and right.
You can also click the middle mouse button to modify a value in bigger increments.
For this example, I will keep auto-key on to show you how this works.
Let's start off by creating a basic animation.
On the first frame, I'll position the graphic to the left and on the last frame I'll position the graphic to the right of the screen.
Scrubbing the time-bar, you can see that this has automatically created animation between the two keyframes.
One important point to note is if I turn auto-key off and try to adjust the x-position containing the animation using the sliders,
the new adjustment will be ignored because I cannot adjust the animation without auto key turned on.
So remember to turn Auto Key on when adjusting channels with existing animation.
If you wanted to reset a channel without going into an animation editor, you can right-click on the slider
and choose the reset option from the pop up menu.
Here you have two options.
You can reset to the original default value or you can reset the animation channel to the current value
of the slider at this frame with no additional animation in the channel.
Just to focus on the sliders for the moment, there are a number of indicators telling you what state the parameter is at.
A simple value tells you the parameter has not been altered.
An asterisk in the slider tells you that the value has been altered.
With regards to animation, a yellow line under the value tells you that there is an animation key-frame at this frame.
The blue line under the value indicates that this slider has an animated channel but you are not on a key-frame.
This means you do not always have to go searching through the animation editor, when looking to find which
channel has animated key-frames.
Holding SHIFT and clicking on a slider selects it, and shows the particular animation key-frames in the time bar.
This allows you to navigate to those key-frames with the navigation controls.
In a sense, this is like a parameter’s own little timeline.
The next example has a few more animated channels.
To the Left of the screen, you will find an animation button. Clicking on this button brings up the animation editor.
The animation editor can be displayed in 3 ways and you see similarities to what you may be used to in other applications.
The first view is the channels editor that shows animation on a curve.
For simplicity’s sake, I’ll refer to this as a curve, even if two keyframes are joined by a straight line,
where no keyframe interpolation has been applied.
Here you can adjust keyframes on the curve to control the speed of the animation per channel.
The second view is the tracks editor that allows you to see the timing of the animation on each channel.
Like in other applications, you can extend the animation or you can click and drag key frames
to adjust timings within the animation.
The third and final view is the info view.
This view displays your animation in a spreadsheet view that can be used to see values without sifting through curves or tracks.
This view can also assist you if you do any animation with expressions.
An expression uses math and logic to automate animation, but we will not cover expressions in this lesson.
Returning to the channel view,
you will see to the left of the channel editors are all the animation channels arranged in a tree structure.
That means you can twirl the triangles to reveal particular animation channels.
When a channel with animation is opened through the hierarchy, its animation curve is revealed.
If you want to hide a particular curve, you simply close the channel.
The animation curve shows your keyframes and the animation generated between the two keyframes.
To see the whole curve in the channel view, press the frame or frame all button below the channel list
to fit the curve or curves to the view.
Ascending and descending curves show changes in the animation values. A flat curve means there is no change in value at that point in time.
Just so that you know,
a white curve is a selected curve and a black curve is not selected.
To select a channel you can simply click on the channel in the list or you could click the curve.
To select individual keyframes, Press COMMAND and drag a box over the keyframe.
You can do this with multiple keyframes too.
Once they are selected you can move the keyframes around simply by clicking on them and dragging them in the channel view.
If you want to copy and paste a channel or keyframes, simply ensure you have selected them first, press copy,
choose the destination channel and press paste. If the positioner is at a different point in time,
then the pasted keyframes will be off-set from the original timing.
Over here you have a cursor pull-down menu and you can switch from various cursor modes.
Choose add and you can click on the animation curve to add additional keyframes.
Or you can choose delete from the pull-down menu to remove keyframes you don’t want by clicking on the keyframes in the curve.
One other cursor mode I want to point out is break.
This cursor allows you to break the symmetrical tangents so that you can adjust the curve individually on either side of the keyframe.
If you want to lock the tangents together again, click on the keyframe using the break cursor.
If you just want to adjust the tangents, remember to switch back to move mode before making the adjustments.
The last mode I want to show you is the Y-scale
This mode allows you to scale the animation vertically. This basically means the values are amplified.
Click and drag on a selected channel or a bunch of selected keyframes, and by dragging up or down will scale the curve
from the point where you click and drag from.
In the cursor pull-down menu, you will also find a X-scale mode that performs the same operation,
only sideways which exponentially increases and decreases the timing of the animation.
There are other cursor modes that will be covered in a future video.
If you prefer a more traditional approach to working with keyframes, you can use the menus to the right of the screen
where you can set keyframes or delete selected keyframes. You also have a reset button to reset selected channels.
To adjust a keyframe to a specific value, you need to select the channel
and navigate to the keyframe with the navigation controls.
In the channel list, click once on the value and type the new value into the calculator.
Pressing enter will confirm the new value and the curve will change.
Looking at the actual curve between the keyframes, you can choose the curve interpolation
or what other software might call smoothing.
To the right of the channel view, you can change the interpolation.
There are a few to choose from and familiar modes such as Bezier, linear and constant should cover most curves you’re after.
To adjust the smoothing on a keyframe, make sure you select the keyframe first,
and then change the interpolation. If you want the entire channel to change,
than select the entire channel and change the interpolation mode.
The final option I am going to show you is the extrapolation.
After an animation has been completed between keyframes, you can choose to loop the animation beyond its initial length.
You can select different repeat modes, such as cycle, and reverse cycle.
Just so that you are aware, there are quite a few other animation tools such as
math operations, audio generated animation, filtering and expressions;
Feel free to discover these tools for yourself.
In the next video we’ll look at tracking and stabilising in the Axis Timeline FX