A comprehensive technical framework for building a sign language virtual assistant using Unity, Blender, and Python ML integration.
Sign Recognition โ Natural Language Processing โ Animation System โ 3D Avatar
(Python) (AI Capabilities) (Unity C#) (Blender+Unity)
SignLanguageAssistant/
โโโ Blender/
โ โโโ Characters/
โ โ โโโ character_creator.py # Low-poly humanoid mesh creation
โ โโโ Animations/ # Animation keyframe library
โ โโโ ExportScripts/
โ โโโ create_hand_rig.py # Automated hand rigging system
โโโ Unity/
โ โโโ Scripts/
โ โ โโโ SignLanguageAvatar.cs # Core animation controller
โ โ โโโ SignRecognitionInput.cs # ML model bridge
โ โ โโโ SignLanguageGenerator.cs # Text-to-sign conversion
โ โ โโโ ProceduralSigning.cs # Animation enhancement
โ โ โโโ VirtualAssistantController.cs # Main assistant logic
โ โ โโโ PerformanceManager.cs # Platform optimization
โ โ โโโ UsageAnalytics.cs # Analytics tracking
โ โโโ Prefabs/ # Avatar prefabs
โ โโโ Materials/ # Avatar materials
โโโ Python/
โโโ SignRecognition/
โ โโโ sign_recognition.py # ML recognition model
โโโ ModelTraining/ # Training scripts
- Creates low-poly humanoid mesh (15k-30k triangles)
- Quad topology optimized for clean deformation
- Detailed hand meshes for clear sign gestures
- Automated UV unwrapping for textures
- Subdivision surface support
- Automated finger bone chain creation
- IK controls for precise positioning
- Shape keys for handshape morphs (ASL/BSL)
- Custom animation controllers
Core animation controller that manages:
- Sign animation library (500+ basic signs)
- Animation queue system
- Smooth transition blending
- Facial expression integration
Key Methods:
void QueueSign(string signGloss) // Queue single sign
void QueueSignSequence(List<string> signs) // Queue multiple signs
bool IsPlaying() // Check playback stateBridges ML recognition to Unity animation
- Receives sign recognition from Python
- Confidence threshold filtering (default: 0.8)
- Sign frequency tracking
- Recognition statistics
Key Methods:
void OnSignRecognized(string sign, float confidence)
void OnSignSequenceRecognized(List<SignData> sequence)
float GetAcceptanceRate()Converts text to sign sequences
- NLP processing for text input
- ASL/BSL grammar rules
- Word-to-sign mapping (50+ common words)
- Automatic fingerspelling for unknown words
Key Methods:
List<string> TextToSignSequence(string text)
void GenerateAndPlaySigns(string text)Enhances animation naturalness
- Coarticulation between signs
- Natural timing variations
- Body sway and breathing
- Eye movement and blinking
Key Methods:
void ApplyCoarticulation(SignAnimation current, SignAnimation next)
void AddNaturalVariation(AnimationClip clip)
void UpdateGazeBehavior(Vector3 target)Main assistant controller
- User query processing
- AI response generation
- State management (Idle, Listening, Processing, Signing)
- Visual feedback system
States:
Listening- Receiving user inputProcessing- Generating AI responseSigning- Animating avatarIdle- Waiting for interaction
Platform-specific optimization
- Mobile optimization (30 FPS, reduced quality)
- Desktop optimization (60 FPS, high quality)
- WebGL optimization (medium quality)
- LOD system for avatars
- Texture compression
- Animation bone reduction
Continuous improvement tracking
- Sign recognition accuracy monitoring
- User correction feedback
- Sign frequency analysis
- Performance metrics
- JSON data export
Real-time sign recognition using MediaPipe
- Hand landmark detection
- Temporal smoothing for stability
- Sign vocabulary (50+ signs + ASL alphabet)
- Unity communication bridge
Key Features:
- Multi-hand tracking (up to 2 hands)
- Confidence thresholding
- Recognition history for stability
- REST API/WebSocket communication
Usage:
from sign_recognition import SignRecognitionModel, SignRecognitionBridge
# Initialize model
model = SignRecognitionModel(confidence_threshold=0.8)
# Create Unity bridge
bridge = SignRecognitionBridge(model, unity_endpoint="http://localhost:8080")
# Run camera loop
bridge.run_camera_loop(camera_id=0)Blender:
- Blender 3.0+ with Python API
Unity:
- Unity 2021.3 LTS or newer
- TextMeshPro package
- Animation Rigging package (optional)
Python:
- Python 3.8+
- OpenCV (
pip install opencv-python) - MediaPipe (
pip install mediapipe) - NumPy (
pip install numpy)
- Clone the repository:
git clone <repository-url>
cd SignLanguageAssistant- Blender Setup:
# Open Blender and run scripts in Text Editor
# Or run from command line:
blender --background --python Blender/Characters/character_creator.py
blender --background --python Blender/ExportScripts/create_hand_rig.py- Unity Setup:
- Open Unity Hub
- Add project from
Unity/directory - Import avatar models from Blender
- Add scripts to appropriate GameObjects
- Python Setup:
cd Python/SignRecognition
pip install -r requirements.txt
python sign_recognition.py-
Create Avatar GameObject:
- Import character from Blender
- Add Animator component
- Configure animation controller
-
Add Core Components:
// Attach to Avatar GameObject
avatar.AddComponent<SignLanguageAvatar>();
avatar.AddComponent<ProceduralSigning>();
// Create separate GameObject for manager
GameObject manager = new GameObject("AssistantManager");
manager.AddComponent<VirtualAssistantController>();
manager.AddComponent<SignLanguageGenerator>();
manager.AddComponent<SignRecognitionInput>();
manager.AddComponent<PerformanceManager>();
manager.AddComponent<UsageAnalytics>();- Configure Sign Library:
- Populate
SignLanguageAvatar.signLibraryin Inspector - Add AnimationClips for each sign
- Set durations and facial expressions
- Populate
// Get references
SignLanguageAvatar avatar = FindObjectOfType<SignLanguageAvatar>();
SignLanguageGenerator generator = FindObjectOfType<SignLanguageGenerator>();
// Play single sign
avatar.QueueSign("HELLO");
// Convert text to signs
generator.GenerateAndPlaySigns("Hello, how are you?");
// Process user query
VirtualAssistantController assistant = FindObjectOfType<VirtualAssistantController>();
assistant.ProcessUserQuery("What is your name?");- Triangle count: 15,000-20,000
- Texture size: 512x512
- Frame rate: 30 FPS
- Bone count: 30 bones
- Shadows: Disabled
- Triangle count: 20,000-30,000
- Texture size: 2048x2048
- Frame rate: 60 FPS
- Bone count: 50 bones
- Shadows: Enabled
- Triangle count: 20,000
- Texture size: 1024x1024
- Frame rate: 30 FPS
- Moderate quality settings
- โ Core animation system
- โ Sign queue management
- โ ML recognition bridge
- โ Text-to-sign conversion
- โ Procedural enhancements
- โ Performance optimization
- โ Analytics tracking
- ๐ 500+ sign animation library
- ๐ Advanced facial expressions
- ๐ Multi-language support (ASL, BSL, LSF)
- โณ Mobile app (iOS/Android)
- โณ AR/VR support
- โณ Voice input integration
- โณ Real-time sign recognition
- โณ Cloud model training
- โณ Multi-avatar support
- Touch interface for manual sign input
- Camera-based sign recognition
- Optimized performance (30 FPS)
- Reduced quality for battery life
- Webcam sign recognition
- High-quality rendering
- Keyboard shortcuts
- Advanced analytics
- Immersive signing experiences
- Spatial sign placement
- Hand tracking integration
- 3D gesture recognition
- Adjustable signing speed (0.5x - 2.0x)
- Multiple signing styles (ASL, BSL, etc.)
- Closed captioning synchronization
- High contrast UI options
- Multiple avatar appearance options
- Sign replay functionality
Tracked Metrics:
- Sign recognition accuracy
- Average confidence scores
- Most frequently used signs
- Signs needing improvement (error rate > 30%)
- User correction patterns
- Session duration
- Total interactions
Export Format:
{
"sessionDuration": 1234.5,
"totalRecognitions": 150,
"recognitionAccuracy": 0.87,
"averageConfidence": 0.91,
"mostUsedSigns": ["HELLO", "THANK", "YOU"],
"signsNeedingImprovement": ["WHAT", "WHERE"]
}# REST API endpoint
@app.route('/sign_recognized', methods=['POST'])
def sign_recognized():
data = request.json
sign = data['sign']
confidence = data['confidence']
# Forward to Unity
return jsonify({'status': 'received'})// Unity REST API receiver
[HttpPost]
public void ReceiveSignRecognition(string json)
{
SignData data = JsonUtility.FromJson<SignData>(json);
signRecognitionInput.OnSignRecognized(data.sign, data.confidence);
}- Test sign queue management
- Test animation transitions
- Test text-to-sign conversion
- Test confidence thresholding
- Test Python-Unity communication
- Test end-to-end sign recognition
- Test multi-sign sequences
- Frame rate monitoring
- Memory usage tracking
- Animation smoothness
- Recognition latency
Contributions are welcome! Areas for improvement:
- Additional sign animations
- Language support (BSL, LSF, JSL, etc.)
- ML model improvements
- UI/UX enhancements
- Documentation
MIT License - See LICENSE file for details
For questions or issues:
- Open a GitHub issue
- Contact: invest@signlanguageai.com
- Documentation: AI.MBTQ.DEV
- AWS GenASL for ASL avatar generation inspiration
- MediaPipe for hand tracking
- Unity Technologies for animation framework
- Blender Foundation for 3D modeling tools
Made with โค๏ธ for accessibility and inclusion
๐ Ready to build? Start with the Blender character creation, then move to Unity integration!