4 Methods of Animation

Animation is a key component of creating engaging UI experiences. Adding flare with motion and color can transform an HMI from something dull and lifeless into something polished and appealing. The term "animation" covers an extremely broad spectrum of disciplines and mediums. Not only that but the way that two animators approach a task may be very different while yielding similar results. In developing Incari, we have been very mindful of this fact and have supplied a variety of different methods for breathing life and character into static assets.

See For Yourself

Using the new Remote Projects section of Incari Hub, we can now provide downloadable projects, which you can play around with to see how certain functionality is implemented in Incari Studio. The first of these mini-projects focuses on the 4 different approaches to animation, which can all be combined together based on the project requirements.

To download the project now, open Incari Hub and download the "Animations" project from the Remote Projects section.

If you go back to the My Projects section, you will see that the project was added to your local files. If you hover over the project thumbnail and press the ▶ (play) icon, you can preview the project.

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Now you will see a variety of controls for each of the 4 animation methods.

  1. Animation Editor - Spins the Incari logo 360°. Note that this kind of animation in Incari is relative, meaning that if you hit the X (stop) button while the sprite is partially rotated, then hit play again, the logo will rotate to the same rotation as it was when you hit the button. These animations are achieved using a keyframe-based

  2. Interpolation - This fades the opacity of the graphic. Interpolation is without a doubt the most programmatic way of approaching animation. It is an entirely node-based method which naturally favors a more parametric way of thinking.

  3. Image Sequence - This animates the logo itself using a pre-rendered sequence of .png files. This allows you to use any 3rd-party animation tool to create animations and then bring them into Incari Studio where you can attach functionality.

  4. Actions - This simply moves the logo from left to right with an easing effect. Actions are node-based, however, unlike the Interpolation approach, these are specifically for animation and are much more akin to tween libraries like TweenLite by GreenSock.

If you open the project from Incari Hub by double-clicking it, we can begin to break don each animation method one by one.

1. Animation Editor

Within the Asset Manager there is a file called "TimelineAnimation.incani". Files with the .incani file type are keyframe-based timeline animations, created using the Animation Editor, which should open automatically when double-clicking on the asset.

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If you expand the Animation Block called "Logo Animation" and its Transformation Attributes you will see that both the Z Position and Z Rotation are highlighted in blue. This indicates that these Attributes have some Keyframes saved on this Animation Block.

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By selecting these Attributes using Ctrl + LMB and then clicking the "focus" icon highlighted above, we can see the animation, represented as Bezier curves.

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A keyframe in the consists or two parts:

  1. The keyframe itself, which holds a value at a specific time.

  2. The curve handles, which control the easing and interpolation between frames.

To add a keyframe, simply right click an Attribute and select "Add Keyframe" from the context menu. This will create a keyframe at whatever time the playhead is currently on. You can then adjust the curve handles to fine-tune the intermediate frames.

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If we take a look into the Logic Editor, you will see that controlling animations is fairly simple. When you play an animation using the Play Animation Block Node, an Instance ID is generated. This is a unique id number which Incari uses to identify which animation you want to stop or pause. If this sounds confusing, don't worry. Just be aware that in order to use the Stop Animation and Pause Animation Nodes you must tell these nodes which animation should be affected.

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Another last point to note is that the Play Animation Block Node has an Attribute for both the Asset (File) _**_and the Animation Block (Name) which will be played. You can drag the .incani file from the Asset Manager directly to the Node to assign it to the File Attribute and select the desired Animation Block from the dropdown menu.

2. Interpolation

Interpolation is a slightly more complex approach to animation. Unlike some of the other options, it is achieved with the Logic Editor alone, using the Interpolate Node. What this does is calculates the intermediate values between an initial and target value over a set amount of time.

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In the example provided in the demo, you will see that each button graphic's On Mouse Click event triggers a sequence of logic. On all three of the buttons, both of the Interpolate Nodes are reset, to make sure that we don't trigger an interpolation, while one is already in progress.

The play forward and play backward buttons have a third Pulse that calculates the interpolation between the current and target opacity values of the logo. Here is a brief overview of the Attributes of the Interpolation Node:

Data Type - The numerical data type which will be interpolated.

Duration - The length of time between the start and end of the interpolation.

Interval Time - This is governs how frequently, in seconds, the interpolated value is calculated and the output Pulse is triggered. On our example, this is set at 0.0167, which is approximately 60 fps (1 / 60 = ~0.0167).

From - This is the value at the start of interpolation. In our example, we are using the current opacity value of our logo as a starting point.

To - This is the value at the end of the interpolation, which in our example, is either 1 or 0.25, depending on which button was pressed.

Type - This is the method that the Interpolate Node uses to calculate the intermediate values. These are similar to those found in many other software and programming languages. A good reference for interpolation types is easings.net.

Mode - Whether the interpolation will be performed once, repeated or alternated.

3. Image Sequence

Although Incari's built-in tools are powerful, there are many use cases where the desired effect can't be achieved using Incari alone. In this case, it often makes more sense to create animations in dedicated animation software. Most tools, such as Adobe After Effects, provide an easy way of exporting an animation as an image sequence, most commonly in the .png file format. By using Incari's Image Sequence Object and Nodes, we can take these frames and combine with Incari's logic system.

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In the Asset Manager of our demo file, you will see a file called "Logo Animation.incseq". Files of the .incseq type are Image Sequences. To open the file, simply double-click it and the Image Sequence Editor will open. Here you can see all of the images of the sequence arranged in order.

To create this type of file, simply right-click in the Asset Manager and select "Create Asset > Image Sequence". Then double-click it to open the Image Sequence Editor, drag the images into it directly from the Asset Manager, and then click the save icon to save it.

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Controlling Image Sequences from the logic is fairly straightforward. If you take a look in the Logic Editor of the demo scene, you will see that there are three main nodes for playing, pausing, and stopping the playback of the Image Sequence.

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While the Pause ImageSequence and Stop ImageSequence are quite self-explanatory, the Play ImageSequence Node has quite a few Attributes, which we will go through now:

  • Start Frame / End Frame - This is the frame index that the animation will start and finish on. Setting these to -1 will tell Incari to start at the first frame and end at the last frame.

  • Object - The Image Sequence Sprite Object, which can be dragged from the Scene Outliner onto the Node.

  • Play Mode - Whether the animation will be played based on frames-per-second (FPS) or a duration (Time). The value of this Attribute will determine which of the following Attributes will be visible:

    • FPS - The frame rate of the animation. This may be preferable if the animation was exported at a specific frame rate that you want to reflect in Incari.

    • Time - The amount of time the animation will take from start to finish. This is useful for tweaking the duration of the animation and can incorporate frame blending using the Interpolation Mode Attribute.

  • Interpolation Mode - This determines whether the animation should fade between one frame and the next. Constant means that frames aren't blended, while Linear means that they are. This Attribute only has an effect when the Play Mode is set to Time.

  • Loop Mode - Whether the Image Sequence plays once (none), plays repeatedly (repeat), or ping-pongs backwards and forwards (alternate).

  • Play Direction - If the animation plays forwards or backwards.

4. Actions

Actions are a set of Nodes designed specifically for animation. In the Toolbox you will see a number of different actions which affect the transformation properties and opacity of Objects.

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The names of these Nodes offers insight into what the Node actually does and which Attribute is affected:

Fade = Opacity

Move = Position

Rotate = Rotation

Scale = Scale

Additionally you will notice three types of actions:

FromTo = Both the start and end value are set manually

To = Only the target value is provided

By = The amount to be animated by relative to the Attribute's current value

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Looking at our example logic, you will see that the logo graphic is moved to a different position depending on which button is pressed. There are also four easing types, defined in the Interpolation Attribute for sine-based and linear interpolation.