Building an AI toy, a desktop companion, or a robot with a screen-based face? You’ll need expressions that communicate what the product is doing—and animation controls your developers can connect to its behavior.
I’m Praneeth Kawya Thathsara, a Rive animator, mascot and character designer, and founder of Mascot Engine.
I help teams design and animate interactive characters, including expressive faces for AI companions and compatible device displays. My work covers character design, rigging, facial animation, state machines, and developer handoff.
Looking to hire a Rive animator? Send me your idea on WhatsApp. Tell me what the face should show, your target platform, and your approximate budget.
What can a Rive animator create for your robot?
The animation scope should follow the interactions your product needs.
A voice companion might need to acknowledge a question, show that it is processing, and speak with coordinated mouth movement. A desktop robot might also need touch reactions, idle behavior, and expressive eyes.
Here are some possible deliverables:
| Feature | What it communicates |
|---|---|
| Idle animation | The character is ready and available |
| Blinking | Subtle life without constant movement |
| Listening expression | The system is receiving user input |
| Thinking animation | A response is being prepared |
| Speaking animation | The character is delivering a response |
| Emotional expressions | Happiness, curiosity, encouragement, or concern |
| Gaze controls | The eyes look toward a supplied position |
| Error and connection states | The interaction needs attention |
| Sleep and wake transitions | The device is resting or becoming active |
You do not need every feature in the first version. A useful first milestone focuses on the states required for your core interaction.
Define the face before building the animation library
A robot face can be as simple as two expressive eyes or as detailed as a complete character.
Before rigging begins, decide:
- Will the face have a mouth?
- Are eyebrows important to its personality?
- Will it appear on a rectangular or circular display?
- How small will it be viewed?
- Should its personality feel playful, calm, curious, or professional?
- Which expressions must remain clear at the actual display size?
A design that looks appealing in a large illustration may need adjustments for a small screen. Fine details, subtle mouth shapes, and low-contrast features should be reviewed at the intended size.
If you already have artwork, it can be assessed for animation preparation. If you only have an idea, the character design can be part of the project.
Agree on how the application will control the face
Your developers and animator should agree on a control contract early.
For example, a project might need the following conceptual controls:
| Control | Purpose |
|---|---|
| Activity | Select idle, listening, thinking, speaking, or sleeping |
| Emotion | Select an expression independently of activity where supported |
| Mouth opening | Adjust how far the mouth opens |
| Viseme | Select a speech-related mouth shape |
| Gaze X / Y | Supply horizontal and vertical look direction |
| Reaction event | Play a short acknowledgement or celebration |
These are planning examples, not required Rive property names or a universal API. The actual controls depend on the rig, runtime, and integration approach.
The handoff should document each control’s name, type, accepted values, default, and expected behavior. If both mouth-opening and viseme controls exist, their priority or switching behavior should also be clear.
This agreement helps avoid a situation where the animation looks correct in the editor but behaves differently in the application.
Choose the right lip-sync scope
“Make the robot talk” can describe several different requirements.
A talking loop
A repeating mouth animation can work for an early demonstration. It starts and stops with the speaking state, but it does not match the actual speech.
Audio-driven mouth opening
The application supplies a value derived from the speech audio level. The animation uses that value to control mouth opening.
This approach can suit simple robot faces. It should include appropriate smoothing and reliable mouth closure during silence.
Viseme-based lip sync
The speech system supplies timed mouth-shape information. The animation maps those values to corresponding shapes.
This can support more articulated speech, but it requires compatible timing data and coordination with the developer.
When requesting a quote, explain which approach you need and what data your speech system can provide. That information changes the animation and integration scope.
What working with Mascot Engine can include
At Mascot Engine, I help founders and development teams turn character ideas into interactive animation assets.
Depending on the agreed scope, I can help with:
- Custom mascot or robot face design.
- Artwork cleanup and preparation.
- 2D character rigging.
- Facial expressions, blinking, and gaze animation.
- Listening, thinking, speaking, and idle states.
- Lip-sync controls.
- Rive state-machine setup.
- Exported animation files and developer documentation.
- Refinement based on integration feedback.
If you want to work with Praneeth Kawya Thathsara on your AI toy or robot face, share your brief on WhatsApp.
You can send existing artwork, a reference video, a sketch, or a short description of the product.
Check hardware compatibility before committing to production
Rive provides runtimes for several platforms, but a display-equipped device is not automatically compatible.
Before planning the full animation library, confirm:
- Device hardware and operating system.
- Application framework and available rendering environment.
- Screen resolution, orientation, and crop.
- Memory and graphics constraints.
- The runtime and features your developers intend to use.
A small prototype on the target hardware is a useful first step. It lets the team assess rendering, behavior, and performance before expanding the project.
The animation scope should also be distinguished from the surrounding engineering work. Conversation AI, speech generation, microphone processing, camera tracking, and motor control require their own implementation.
For a relevant real-world example, Rive’s MIRA case study describes an AI robot installation that used Rive to animate facial emotions and manage transitions.
Ask for transition testing
Individual expressions are only part of the work. The character also needs to move between states predictably.
Useful review scenarios include:
- Listening changes to thinking.
- Thinking changes directly to speaking.
- A user interrupts speech.
- Audio stops and the mouth closes.
- Emotion changes during speech.
- A connection error interrupts the current activity.
- The character returns to idle after recovery.
- Repeated events arrive before the previous reaction finishes.
For each scenario, agree on the expected result.
This makes feedback more actionable than simply saying that an animation “feels wrong.” It also helps identify whether an issue comes from the animation logic, application timing, or supplied values.
What affects the project cost?
An accurate quote depends on the work involved.
Common factors include:
- Whether the character already exists.
- The condition and format of the source artwork.
- Rig complexity.
- Number of states and expressions.
- Lip-sync requirements.
- Independent emotion and gaze controls.
- Character variants or accessories.
- Hardware testing and integration support.
- Revision scope and delivery timeline.
A simple eyes-only face with a few states will have a different scope from a full character with articulated speech, independent emotions, and multiple variations.
Share your approximate budget early. We can discuss the essential first milestone and which features could follow later.
A brief you can copy
You can use this template when contacting me:
Product idea:
What does your AI toy or robot do?Target users:
Who will interact with it?Device and platform:
What hardware, operating system, and framework are you using?Display:
Resolution, orientation, and any circular crop.Character artwork:
Existing artwork, references, or a new design needed.Required behavior:
What should the face show while idle, listening, thinking, speaking, or encountering an error?Speech integration:
Talking loop, audio-driven mouth movement, or timed viseme data?Budget:
Your approximate range.Timeline:
When do you need the first prototype or delivery?
It is fine to leave technical details open if you have not decided them yet. We can identify what needs clarification before production.
Let’s discuss your AI toy or robot face
I’m Praneeth Kawya Thathsara, founder of Mascot Engine.
If you need a Rive animator to help create an expressive, interactive face, tell me about your project:
What is your AI robot idea? What should its face show? What budget are you working with?
I’ll review the details, explain where I can support you, and help define a practical animation scope and next steps.
- Website: mascotengine.com
- WhatsApp: +94 71 700 0999
- Email: mascotengine@gmail.com
Top comments (0)