How to Use Runway Act-Two for Creative Projects

Runway Act-Two is a revolutionary motion capture model that brings characters to life through driving performance videos, adding vivid movements, expressions, and voice. Compared to its predecessor Act-One, Act-Two has achieved significant improvements in fidelity, consistency, and motion capture. This article will detail how to use Act-Two to create impressive character animations.

What is Act-Two?

Act-Two is Runway’s latest next-generation motion capture model with the following core features:

Superior Generation Quality: Significant improvements in fidelity, consistency, and motion compared to Act-One
Complete Performance Capture: Supports comprehensive tracking of head, facial expressions, upper body, hands, and background
Universal Character Compatibility: Can animate any character, suitable for different environments, styles, and artistic directions
Simplified Input Requirements: Only requires driving performance video and reference character to start creating

Technical Specifications

Before getting started, let’s understand Act-Two’s technical specifications:

Item	Details
Supported Duration	Up to 30 seconds
Output Resolution	16:9 (1280x720), 9:16 (720x1280), 1:1 (960x960), 4:3 (1104x832), 3:4 (832x1104), 21:9 (1584x672)
Frame Rate	24fps
Platform	Web
Gesture Control	Supported (character images only)

Step 1: Choose Input Content

Using Act-Two requires two core inputs:

1. Driving Performance Video

This is a video of a person performing a scene, containing the movements, expressions, audio, and gestures you want to transfer to the character. You can:

Record performance video directly through the web application
Drag and drop video files from your computer to the prompt canvas

2. Character Input

Can be an image or video representing the character you want to bring to life.

Character Image vs Character Video

Choosing between character image or character video affects the final animation:

Advantages of Using Character Images:

Automatically adds environmental motion, creating more natural shot effects
Supports controlling gestures and body movements through performance video
Provides a smoother creative experience

Characteristics of Using Character Videos:

Preserves the original video’s subject, environment, and camera movement
Primarily controls facial movements and expressions
Does not support gesture control

Step 2: Configure Settings

Act-Two provides two main settings to optimize your creation:

Gesture Control (Gestures)

This setting controls whether to transfer poses, gestures, and body movements from the performance video to the character image:

Enabled: Closely follows the performance video, may change the character’s pose
Disabled: Focuses on adding facial and environmental motion

Note: This setting is only available when using character images; character videos automatically use the original video’s movements.

Facial Expressiveness

Controls the amount of facial motion transferred from the driving performance to the character, with a default value of 3:

Lower values: Less expressiveness, but may improve character consistency in some cases
Higher values: More expressiveness, but may cause visual artifacts in some cases

It’s recommended to test with the default value first, then adjust based on results.

Step 3: Generate Act-Two Video

Start Generation

Open a session in your dashboard
Ensure Gen-4 video model is selected
Click the Act-Two icon in the bottom left corner
Upload driving performance video and character input
Configure settings
Review estimated credit cost
Click generate button

Understanding Pricing

Act-Two charges 5 credits per second, with a minimum of 3 seconds. This means even performance videos shorter than 3 seconds will be charged 15 credits.

Best Practice Recommendations

Performance Video Best Practices:

Ensure clear facial expressions and movements
Avoid excessive camera shake
Use good lighting conditions
Keep performance natural and smooth

Character Input Best Practices:

Choose high-quality images or videos
Ensure character face is clearly visible
Consider character style and environment matching
If using images, try to match poses in the performance

Creative Tips

Suggestions for Better Results:

Match Poses: If using character images, try to match character poses and orientation in the performance
Test Settings: Experiment with different gesture control and facial expressiveness settings
Maintain Consistency: Use similar lighting and angles for better results
Control Duration: Consider costs and reasonably control video duration

Common Problem Solutions:

If character looks unnatural, try adjusting facial expressiveness settings
If movements are inaccurate, check performance video quality and clarity
If you need to maintain character’s original pose, disable gesture control

Future Development

Act-Two is currently being rolled out in phases, currently available only to enterprise and creative partners. As the platform expands availability, access will be opened to all users in the coming days.

Conclusion

Runway Act-Two represents a major breakthrough in motion capture technology, simplifying the professional-grade character animation creation process. By understanding its features, mastering proper usage methods, and following best practices, you can create impressive character animation works.

Whether you’re a professional animator or creative enthusiast, Act-Two provides you with a powerful and intuitive tool to realize your creative vision. As technology continues to evolve, we can expect to see more innovative applications and higher quality animation works.

Appendix

Start your Act-Two creative journey now!