AI for Learning Photorealistic 3D Digital Humans from In-the-Wild Data

Silicon Valley ACM SIGGRAPH
19 Apr 202478:34

TLDRThe presentation by Matthew from Nvidia Research delves into the cutting-edge technology of creating photorealistic 3D digital humans using AI. Leveraging generative adversarial networks (GANs), the process involves converting 2D images into high-quality, robust, and efficient 3D representations without the need for complex 3D ground truth data. Matthew discusses the evolution of GANs, their ability to generate realistic human images, and the challenges of creating 3D objects from 2D data. He introduces a hybrid representation that combines the benefits of both implicit and explicit feature grids to reduce computational costs. The method trains on synthetic data, achieving real-time performance and maintaining high-resolution details. Potential applications include enhanced teleconferencing, personalized avatars, and real-time translations, offering a more engaging and realistic virtual presence. The technology's implications for deep fakes and data privacy are also acknowledged.

Takeaways

  • 📈 The development of AI for creating photorealistic 3D digital humans from in-the-wild data is progressing rapidly, with applications in telepresence and virtual meetings.
  • 🎓 Matthew, an Nvidia research engineer, focuses on the intersection of graphics and generative models, particularly in 3D scene reconstruction and understanding.
  • 🚀 Nvidia's approach to learning photorealistic 3D people involves leveraging AI to create high-quality, robust, and efficient digital humans from widely available online data.
  • 🧠 The use of Generative Adversarial Networks (GANs) has evolved to produce highly realistic images and faces, with recent advancements including 3D aware GANs for creating 3D objects and scenes.
  • 👀 A hybrid representation combining tri-plane feature planes with a small MLP allows for efficient and high-quality 3D scene representation, reducing computational costs.
  • 🔍 Nvidia's method trains entirely from 2D in-the-wild images, making it more accessible and cost-effective than traditional 3D data acquisition methods.
  • 🔁 The process of 3D GAN training involves rendering 2D images from 3D representations and using discriminators to improve realism, without the need for 3D ground truth data.
  • 🖼️ The challenge of maintaining high image quality while reducing computational complexity is addressed by intelligent sampling and a surface-aware SDF-based neurofield.
  • ⏱️ Real-time Radiance Fields for single view synthesis can create 3D avatars from a single image, aiming to simplify the 2D to 3D lifting process for consumer hardware.
  • 🤝 The technology has potential applications in improving virtual communication by providing a more engaging and realistic 3D telepresence experience.
  • 🌐 Future work includes enhancing the model to better handle full-body captures, improving the temporal consistency of generated videos, and addressing ethical concerns related to deep fakes.

Q & A

  • What is the main focus of Matthew's presentation?

    -Matthew's presentation focuses on the technology behind creating photorealistic 3D digital humans from in-the-wild data using AI, specifically for applications like telepresence and 3D video conferencing.

  • What are some of the challenges in creating 3D digital humans?

    -Challenges include the computational cost of training GANs, the need for high-quality and efficient digital humans, and the difficulty of capturing 3D data in the wild. The process also requires handling the ambiguity introduced when flattening a 3D object into a single 2D image.

  • How does Nvidia's approach to 3D scene understanding and reconstruction differ from previous attempts?

    -Nvidia's approach leverages AI to create digital humans from easily capturable and widely available online data. They explore bending reality to improve communication and use generative models, specifically GANs, to produce high-quality 3D representations without needing 3D ground truth data.

  • What is the significance of using StyleGAN in the process of generating 3D humans?

    -StyleGAN is used to generate 2D images of people that can then be used to train a 3D model. This approach allows for the creation of photorealistic synthetic 3D data, which can be rendered into 2D images for training a separate AI model for 2D to 3D lifting.

  • How does the proposed method for 2D to 3D lifting using a Vision Transformer work?

    -The method uses a two-step approach where a low-resolution 3D deep feature is extracted and fed into a Vision Transformer. This is then combined with high-resolution details using a second Vision Transformer to produce a final output that is both 3D consistent and maintains high-resolution details.

  • What are some potential applications of the technology discussed in the presentation?

    -Applications include improving telepresence and 3D video conferencing, creating avatars for the metaverse, and editing 2D images to enhance realism for transferring people into shared world spaces. It can also be used for real-time translations and maintaining eye contact in video communications.

  • How does the technology handle the issue of data privacy?

    -Currently, there is no public access to the technology due to data privacy concerns. The team is cautious about releasing a product that could potentially be misused to create deep fakes or compromise individual privacy.

  • What is the end-to-end latency for the 3D representation in a video conferencing scenario?

    -The end-to-end latency is about 80 to 100 milliseconds, which is on par with existing 2D video conferencing systems.

  • How does the technology address the problem of temporal consistency in video sequences?

    -While the current model does not have built-in temporal consistency, ongoing work is being done to address this issue. This includes techniques to fuse frames and maintain consistency as people move or talk within a video sequence.

  • What is the potential impact of this technology on the film and entertainment industry?

    -The technology can be used to create digital twins of actors and performers, allowing for new forms of interaction and immersive experiences in the metaverse. It can also facilitate the creation of realistic 3D characters from 2D footage, potentially revolutionizing post-production processes.

  • How does the technology handle the generation of 3D objects from in-the-wild 2D images that may have varying qualities and characteristics?

    -The technology uses aggressive augmentation schemes on the synthetic data to ensure that the model generalizes well to in-the-wild images. This includes modifications to pitch, yaw, camera parameters, and other factors to simulate the variability found in natural imagery.

Outlines

00:00

🗣️ Event Introduction and Upcoming Schedule

The paragraph introduces various event organizers and volunteers, outlines the upcoming events including a metaverse conference on May 14th, 2024, an annual art show with over 20 artists, and an outdoor multimedia show named 'Open Sky'. The speaker encourages audience participation in these events and introduces the night's speaker, Ken, who will discuss 3D video conferencing technology.

05:00

🤖 Nvidia's Research on 3D Digital Humans

Matthew, a research engineer at Nvidia, talks about the company's approach to creating photorealistic 3D people using AI. He explains that they leverage online data to generate high-quality digital humans and discusses the potential applications of telepresence. Matthew also shares his academic background and the focus of his research on the intersection of graphics and generative models.

10:00

🎨 StyleGAN and the Evolution of GANs

The discussion delves into the specifics of Generative Adversarial Networks (GANs), particularly StyleGAN, and their rapid evolution over the past decade. Matthew explains how GANs have progressed from producing indistinguishable human faces to more complex 3D representations. He also touches on the computational efficiency and the potential of using GANs for creating 3D objects and scenes from 2D images.

15:01

🌐 3D Representations and Real-Time Rendering

Matthew elaborates on the challenges and advancements in 3D representation, specifically discussing the use of Neural Radiance Fields (NeRF) for creating 3D objects from 2D images. He addresses the computational costs and introduces a hybrid representation called Tri-Plane to improve efficiency. The discussion also covers the importance of rendering each pixel for high-quality output and the potential of real-time rendering for applications like video conferencing.

20:03

🚀 Real-Time 3D Lifting and AI Applications

The presentation introduces a method for real-time 3D lifting of single-view images to create 3D avatars that can be manipulated and rendered. The process aims to be simple, fast, and accessible, using AI to transform 2D images into 3D models without the need for expensive equipment or extensive fine-tuning. The potential applications include enhancing teleconferencing experiences and creating digital twins for the metaverse.

25:05

🎭 Future of 3D Teleconferencing and Deepfakes

Matthew discusses the potential of using AI for 3D teleconferencing, suggesting that it could make remote interactions more engaging and less mentally fatiguing. He also touches on the ethical concerns surrounding deepfakes and the importance of using the technology responsibly. The conversation concludes with a Q&A session where Matthew addresses questions about the potential applications, challenges, and future directions of the technology.

Mindmap

Keywords

💡Photorealistic 3D Digital Humans

Photorealistic 3D digital humans refer to the creation of digital characters that closely resemble real people in terms of their appearance and behavior. In the context of the video, this involves using AI to generate high-quality, robust, and efficient digital humans from easily capturable and widely available data online. The speaker discusses how Nvidia is leveraging AI to create these characters for applications such as telepresence and virtual meetings.

💡Generative Adversarial Networks (GANs)

Generative Adversarial Networks, or GANs, are a class of AI algorithms used to generate new data samples that are similar to the training data. In the video, GANs are crucial for creating realistic images and 3D representations of people. The speaker explains how GANs have evolved to produce images indistinguishable from real ones, which is foundational to the development of photorealistic 3D humans.

💡Telepresence

Telepresence is the feeling of being present, as if one were in a different location through the use of technology. It is a key application discussed in the video where 3D digital humans can be used to allow people to be digitally present at remote locations. The speaker mentions how this technology could enhance virtual meetings by providing a more engaging and realistic experience.

💡Codec Avatars

Codec avatars are digital representations of a person used in virtual environments. The term is mentioned in the context of Meta's attempt to solve the problem of telepresence through the use of these avatars with their headsets. The speaker discusses how these avatars are part of the evolution towards more immersive and realistic virtual communication.

💡Project Starline

Project Starline is an initiative by Google to create a 3D telepresence experience without the need for headsets. It is mentioned as a notable attempt to achieve realistic 3D presence of people. The speaker uses this as an example of industry efforts to improve remote communication through more natural and lifelike representations of individuals.

💡Nvidia Research

Nvidia Research is the division of the company that focuses on developing cutting-edge technologies, including those related to graphics and generative models. In the video, the speaker introduces himself as a part of Nvidia Research, where he works on the intersection of graphics and generative models, specifically in relation to 3D scene reconstruction and understanding.

💡3D Scene Reconstruction

3D scene reconstruction is the process of creating a three-dimensional representation of a scene from two-dimensional images or data. It is a key technology in the field of computer vision and is central to the creation of realistic 3D digital humans, as discussed in the video. The speaker's work involves using AI to improve the quality and efficiency of 3D scene reconstruction.

💡Neural Radiance Fields (NeRF)

Neural Radiance Fields, or NeRF, is a method for rendering complex scenes with high fidelity by using a neural network to represent the volume density and emitted radiance at each point in space. In the video, the speaker discusses how NeRF is used as a representation of choice for many 3D GANs to achieve high-quality 3D image synthesis.

💡Single Image 3D Lifting

Single image 3D lifting is the process of creating a 3D representation of an object or person from a single 2D image. The speaker introduces a method for real-time 3D lifting that can generate a 3D avatar from a single portrait view image. This technology aims to simplify the process of creating 3D models from 2D inputs, which has applications in areas such as video teleconferencing and virtual reality.

💡Deep Fakes

Deep fakes are synthetic media in which a person's likeness is replaced with another's using AI and machine learning. The speaker acknowledges the potential for deep fakes to be a concern with the technology discussed, as creating convincing 3D representations of people can be misused to impersonate individuals. The video touches on the ethical considerations and the need for responsible development and use of such technology.

💡Metaverse

The metaverse is a collective virtual shared space, created by the convergence of virtually enhanced reality and physically persistent virtual reality. The speaker discusses the potential application of the technology in creating more immersive and interactive experiences within the metaverse, suggesting that the 3D digital humans could enhance the sense of presence and realism in virtual environments.

Highlights

Matthew, an Nvidia research engineer, discusses the technology behind 3D video conferencing and digital human creation.

The goal is to use AI to create high-quality, robust, and efficient digital humans from widely available online data.

3D digital humans have applications in telepresence, enabling digital presence across distances.

Nvidia explores bending reality to improve communication through stylized and personalized 3D avatars.

Generative Adversarial Networks (GANs) are utilized to convert random numbers into images of people that don't exist.

Nvidia's StyleGAN2 and StyleGAN3 are mentioned for their state-of-the-art image synthesis capabilities.

3D GANs or 3D aware GANs are trained using unstructured images of 2D people to generate multiview consistent 3D objects and scenes.

The challenge of training GANs lies in their computational cost and the need for a large number of synthesized images to converge.

Nvidia proposes a hybrid representation combining feature planes with a small MLP for efficient 3D representation.

A feedforward sampler is introduced to intelligently sample only the regions of space that are important for rendering.

The method achieves real-time performance on consumer hardware and uses single-view inputs for 3D avatar creation.

The process involves a two-step approach using deep feature extractors and vision transformers for high-resolution 3D representation.

The model shows amazing generalization to out-of-domain inputs, including stylized and cartoonish images.

Applications discussed include 3D telepresence for video conferencing, enhancing the sense of realism in metaverse interactions.

The technology allows for the composition of existing 2D modification methods into 3D, such as stylization and personalized avatars.

Nvidia's approach works entirely from 2D video, enabling features like eye contact editing and real-time translations.

The end-to-end latency for the 3D representation in video conferencing is about 80 to 100 milliseconds.

The potential for deep fakes is acknowledged, and responsible development and use of the technology are emphasized.