The Wanderings of Odysseus in 3D Scenes

TL;DR

GAMMA generates realistic motions for diverse 3D bodies using body surface markers, enhancing motion control and scene interaction.

cs.CV 🔴 Advanced 2021-12-17 2 views
Yan Zhang Siyu Tang
3D scenes generative model motion control virtual humans CVAE

Key Findings

Methodology

This study introduces GAMMA, a method using body surface markers and Conditional Variational Autoencoder (CVAE) to generate motion primitives. The method decomposes long-term motion into a sequence of motion primitives and implements the generative model recursively. To control motion towards a goal, a policy network explores the generative model's latent space, and a tree-based search maintains motion quality during testing.

Key Results

  • Experiments show that GAMMA outperforms existing data-driven methods in generating more realistic and controllable motion. With conventional path-finding algorithms, the generated human bodies can realistically move long distances in the scene.
  • Compared to existing methods, GAMMA excels in motion control and scene interaction, reducing common issues like foot-skating.
  • GAMMA demonstrates good generalization across various body shapes and action types.

Significance

This research holds significant value for academia and industry. It addresses the long-standing challenge of generating realistic motion for virtual humans in 3D scenes, enhancing AR/VR user experiences and providing architects with better foresight into design functionalities. By generating diverse virtual populations, this technology can be widely applied in gaming, film, education, and more.

Technical Contribution

GAMMA distinguishes itself from existing methods by introducing body surface markers and CVAE to solve the challenge of generating long-term diverse motions. Its policy network and tree-based search further enhance motion controllability and realism, opening new possibilities for generative model applications.

Novelty

GAMMA is the first to combine body surface markers with CVAE for generating 3D human motion. Compared to traditional methods, its innovation lies in achieving motion controllability and diversity through recursive generative models and policy networks.

Limitations

  • In complex scenes, GAMMA may struggle with all geometric constraints, leading to motion distortion.
  • The high computational resource requirement may limit its use in real-time applications.

Future Work

Future work could explore GAMMA's application in more complex scenes and optimize its computational efficiency. Additionally, integrating other sensor data could enhance the realism of motion generation.

AI Executive Summary

Recent advancements in 3D technology have made the generation of virtual populations in digital environments a critical topic. However, existing solutions struggle to achieve realistic motion for diverse 3D bodies. To address this, researchers have introduced a new method called GAMMA, which uses body surface markers and Conditional Variational Autoencoder (CVAE) to generate motion primitives. GAMMA decomposes long-term motion into a sequence of motion primitives and implements the generative model recursively. Experiments show that GAMMA outperforms existing data-driven methods in generating more realistic and controllable motion.

The core technologies of GAMMA include a policy network and a tree-based search, enhancing motion controllability and realism. These technologies enable virtual populations to move realistically in 3D scenes for extended periods, enhancing AR/VR user experiences and providing architects with better foresight into design functionalities. GAMMA's innovation lies in being the first to combine body surface markers with CVAE for generating 3D human motion, solving the challenge of generating long-term diverse motions.

Despite significant technical advancements, GAMMA may struggle with all geometric constraints in complex scenes, leading to motion distortion. Additionally, the high computational resource requirement may limit its use in real-time applications. Future work could explore GAMMA's application in more complex scenes and optimize its computational efficiency.

Deep Analysis

Background

The rapid development of 3D technology has driven the generation of virtual populations in digital environments. However, existing solutions struggle to achieve realistic motion for diverse 3D bodies. Traditional methods often rely on pre-designed 3D characters and pre-recorded motion data, making it difficult to handle diverse behaviors of a large number of characters. Recently, the availability of large-scale motion capture datasets has facilitated the learning of generative motion models, but these models often produce motion limited to a few seconds with issues like jittering and foot-skating.

Core Problem

The core problem is generating realistic, controllable, and infinitely long motions for diverse 3D bodies. Existing methods treat motion as a standard time sequence of high-dimensional feature vectors and propose to model it with a single deep neural network. However, as time progresses, the uncertainty of human motion increases, and it is unclear whether a single neural network has sufficient power to represent perpetual motion.

Innovation

GAMMA's core innovation lies in generating motion primitives using body surface markers and Conditional Variational Autoencoder (CVAE). The method decomposes long-term motion into a sequence of motion primitives and implements the generative model recursively. The policy network and tree-based search further enhance motion controllability and realism.

Methodology

  • �� Decompose long-term motion into motion primitives, using body surface markers and CVAE to model each primitive.
  • �� Implement the generative model recursively to generate long-term motion.
  • �� Apply a policy network to explore the generative model's latent space, controlling motion to reach a goal.
  • �� Use a tree-based search to maintain motion quality during testing.

Experiments

Experiments use the large-scale motion capture dataset AMASS for training and testing. The performance of GAMMA in motion realism and controllability is evaluated by comparing it with existing methods. Results show that GAMMA outperforms existing data-driven methods in generating more realistic and controllable motion.

Results

GAMMA excels in generating more realistic and controllable motion, reducing common issues like foot-skating. It demonstrates good generalization across various body shapes and action types. Compared to existing methods, GAMMA excels in motion control and scene interaction.

Applications

GAMMA can be widely applied in gaming, film, education, and more, enhancing AR/VR user experiences and providing architects with better foresight into design functionalities. Its generated diverse virtual populations can move realistically in 3D scenes for extended periods.

Limitations & Outlook

GAMMA may struggle with all geometric constraints in complex scenes, leading to motion distortion. Additionally, the high computational resource requirement may limit its use in real-time applications. Future work could explore GAMMA's application in more complex scenes and optimize its computational efficiency.

Plain Language Accessible to non-experts

Imagine you're in a virtual world where characters need to move like real people. GAMMA is like a smart director that makes these virtual characters move naturally in the scene. By using body surface markers and a technique called CVAE, GAMMA can generate diverse motions, like a director giving actors different scripts to ensure their performances are realistic. The policy network acts like the director's assistant, helping adjust each actor's movements so they can smoothly reach their target locations. The tree-based search is like the director's review team, ensuring every action meets the standards and no mistakes occur. This way, the entire virtual world is lively, and characters can explore and interact freely.

ELI14 Explained like you're 14

Imagine you're playing a super cool virtual reality game where the characters look and move just like real people! GAMMA is the secret weapon that makes these virtual characters move. It's like a super-smart game engine that lets virtual characters roam freely in the game world, just like you're controlling them. It uses a technique called CVAE to make sure every move is smooth and natural, like watching an action movie. There's also a policy network that helps plan each character's route, so they don't get lost. Finally, the tree-based search is like the game's quality checker, making sure all moves are perfect. Isn't that awesome?

Glossary

GAMMA (Generative Motion primitive via body surface Markers)

A method for generating diverse 3D human motions using body surface markers.

Used for generating realistic motion of virtual populations.

CVAE (Conditional Variational Autoencoder)

A generative model for handling data with conditional information.

Used for modeling motion primitives.

Policy Network

A network used to explore the latent space of the generative model.

Used to control motion towards a goal.

Tree-based Search

A search method used to maintain motion quality during testing.

Used to filter out high-quality motion primitives.

Motion Primitives

Basic motion units after decomposing long-term motion.

Used for recursively generating long-term motion.

Open Questions Unanswered questions from this research

  • 1 How to handle all geometric constraints in complex scenes remains an open question.
  • 2 GAMMA's computational efficiency in real-time applications needs improvement.

Applications

Immediate Applications

Game Development

GAMMA can be used to generate virtual character motions in games, enhancing realism and interactivity.

Long-term Vision

Architectural Design

By simulating virtual populations moving in buildings, GAMMA can help architects optimize designs.

Abstract

Our goal is to populate digital environments, in which digital humans have diverse body shapes, move perpetually, and have plausible body-scene contact. The core challenge is to generate realistic, controllable, and infinitely long motions for diverse 3D bodies. To this end, we propose generative motion primitives via body surface markers, or GAMMA in short. In our solution, we decompose the long-term motion into a time sequence of motion primitives. We exploit body surface markers and conditional variational autoencoder to model each motion primitive, and generate long-term motion by implementing the generative model recursively. To control the motion to reach a goal, we apply a policy network to explore the generative model's latent space and use a tree-based search to preserve the motion quality during testing. Experiments show that our method can produce more realistic and controllable motion than state-of-the-art data-driven methods. With conventional path-finding algorithms, the generated human bodies can realistically move long distances for a long period of time in the scene. Code is released for research purposes at: \url{https://yz-cnsdqz.github.io/eigenmotion/GAMMA/}

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