The ability to create realistic, animatable and relightable head avatars from casual video sequences would open up wide ranging applications in communication and entertainment. Current methods either build on explicit 3D morphable meshes (3DMM) or exploit neural implicit representations. The former are limited by fixed topology, while the latter are non-trivial to deform and inefficient to render. Furthermore, existing approaches entangle lighting in the color estimation, thus they are limited in re-rendering the avatar in new environments. In contrast, we propose PointAvatar, a deformable point-based representation that disentangles the source color into intrinsic albedo and normal-dependent shading. We demonstrate that PointAvatar bridges the gap between existing mesh- and implicit representations, combining high-quality geometry and appearance with topological flexibility, ease of deformation and rendering efficiency. We show that our method is able to generate animatable 3D avatars using monocular videos from multiple sources including hand-held smartphones, laptop webcams and internet videos, achieving state-of-the-art quality in challenging cases where previous methods fail, e.g., thin hair strands, while being significantly more efficient in training than competing methods.

The combination of artist-curated scans, and deep implicit functions (IF), is enabling the creation of detailed, clothed, 3D humans from images. However, existing methods are far from perfect. IF-based methods recover free-form geometry but produce disembodied limbs or degenerate shapes for unseen poses or clothes. To increase robustness for these cases, existing work uses an explicit parametric body model to constrain surface reconstruction, but this limits the recovery of free-form surfaces such as loose clothing that deviates from the body. What we want is a method that combines the best properties of implicit and explicit methods. To this end, we make two key observations: (1) current networks are better at inferring detailed 2D maps than full-3D surfaces, and (2) a parametric model can be seen as a "canvas" for stitching together detailed surface patches. ECON infers high-fidelity 3D humans even in loose clothes and challenging poses, while having realistic faces and fingers. This goes beyond previous methods. Quantitative, evaluation of the CAPE and Renderpeople datasets shows that ECON is more accurate than the state of the art. Perceptual studies also show that ECON's perceived realism is better by a large margin. Code and models are available for research purposes at https://xiuyuliang.cn/econ

We propose a method that leverages graph neural networks, multi-level message passing, and unsupervised training to enable real-time prediction of realistic clothing dynamics. Whereas existing methods based on linear blend skinning must be trained for specific garments, our method is agnostic to body shape and applies to tight-fitting garments as well as loose, free-flowing clothing. Our method furthermore handles changes in topology (e.g., garments with buttons or zippers) and material properties at inference time. As one key contribution, we propose a hierarchical message-passing scheme that efficiently propagates stiff stretching modes while preserving local detail. We empirically show that our method outperforms strong baselines quantitatively and that its results are perceived as more realistic than state-of-the-art methods.

This work addresses the problem of generating 3D holistic body motions from human speech. Given a speech recording, we synthesize sequences of 3D body poses, hand gestures, and facial expressions that are realistic and diverse. To achieve this, we first build a high-quality dataset of 3D holistic body meshes with synchronous speech. We then define a novel speech-to-motion generation framework in which the face, body, and hands are modeled separately. The separated modeling stems from the fact that face articulation strongly correlates with human speech, while body poses and hand gestures are less correlated. Specifically, we employ an autoencoder for face motions, and a compositional vector-quantized variational autoencoder (VQ-VAE) for the body and hand motions. The compositional VQ-VAE is key to generating diverse results. Additionally, we propose a cross-conditional autoregressive model that generates body poses and hand gestures, leading to coherent and realistic motions. Extensive experiments and user studies demonstrate that our proposed approach achieves state-of-the-art performance both qualitatively and quantitatively. Our novel dataset and code will be released for research purposes at https://talkshow.is.tue.mpg.de.

Generating realistic 3D worlds occupied by moving humans has many applications in games, architecture, and synthetic data creation. But generating such scenes is expensive and labor intensive. Recent work generates human poses and motions given a 3D scene. Here, we take the opposite approach and generate 3D indoor scenes given 3D human motion. Such motions can come from archival motion capture or from IMU sensors worn on the body, effectively turning human movement in a "scanner" of the 3D world. Intuitively, human movement indicates the free-space in a room and human contact indicates surfaces or objects that support activities such as sitting, lying or touching. We propose MIME (Mining Interaction and Movement to infer 3D Environments), which is a generative model of indoor scenes that produces furniture layouts that are consistent with the human movement. MIME uses an auto-regressive transformer architecture that takes the already generated objects in the scene as well as the human motion as input, and outputs the next plausible object. To train MIME, we build a dataset by populating the 3D FRONT scene dataset with 3D humans. Our experiments show that MIME produces more diverse and plausible 3D scenes than a recent generative scene method that does not know about human movement. Code and data will be available for research at https://mime.is.tue.mpg.de.

Neural fields have revolutionized the area of 3D reconstruction and novel view synthesis of rigid scenes. A key challenge in making such methods applicable to articulated objects, such as the human body, is to model the deformation of 3D locations between the rest pose (a canonical space) and the deformed space. We propose a new articulation module for neural fields, Fast-SNARF, which finds accurate correspondences between canonical space and posed space via iterative root finding. Fast-SNARF is a drop-in replacement in functionality to our previous work, SNARF, while significantly improving its computational efficiency. We contribute several algorithmic and implementation improvements over SNARF, yielding a speed-up of $150\times$. These improvements include voxel-based correspondence search, pre-computing the linear blend skinning function, and an efficient software implementation with CUDA kernels. Fast-SNARF enables efficient and simultaneous optimization of shape and skinning weights given deformed observations without correspondences (e.g. 3D meshes). Because learning of deformation maps is a crucial component in many 3D human avatar methods and since Fast-SNARF provides a computationally efficient solution, we believe that this work represents a significant step towards the practical creation of 3D virtual humans.

来自多个RGB摄像机的无标记人类运动捕获（MOCAP）是一个广泛研究的问题。现有方法要么需要校准相机，要么相对于静态摄像头校准它们，该摄像头是MOCAP系统的参考框架。每个捕获会话都必须先验完成校准步骤，这是一个乏味的过程，并且每当有意或意外移动相机时，都需要重新校准。在本文中，我们提出了一种MOCAP方法，该方法使用了多个静态和移动的外部未校准的RGB摄像机。我们方法的关键组成部分如下。首先，由于相机和受试者可以自由移动，因此我们选择接地平面作为常见参考，以代表身体和相机运动，与代表摄像机坐标中身体的现有方法不同。其次，我们了解相对于接地平面的短人类运动序列（$ \ sim $ 1SEC）的概率分布，并利用它在摄像机和人类运动之间消除歧义。第三，我们将此分布用作一种新型的多阶段优化方法的运动，以适合SMPL人体模型，并且摄像机在图像上的人体关键点构成。最后，我们证明我们的方法可以在从航空摄像机到智能手机的各种数据集上使用。与使用静态摄像头的单眼人类MOCAP任务相比，它还提供了更准确的结果。我们的代码可在https://github.com/robot-ception-group/smartmocap上进行研究。

为了追踪和运动捕获（MOCAP）在其自然栖息地中的动物，非常适合安全和无声的空中平台，例如带有车载摄像机的飞艇。但是，与多旋转器不同，飞艇受到严格的运动限制和受环境风的影响。它们的方向和飞行方向也紧密耦合。因此，用于感知任务的基于最新的MPC的形成控制方法不适用于飞艇团队。在本文中，我们首先利用飞艇的空速与其与主题的距离之间的定期关系来解决这个问题。我们使用它来得出满足MOCAP感知约束的分析和数字解决方案。基于此，我们开发了一个基于MPC的编队控制器。我们对解决方案进行了详细的分析，包括改变物理参数（例如攻击角度和俯仰角）的影响。提出了广泛的仿真实验，比较了不同的形成大小，不同的风条件和各种受试者速度的结果。还包括我们关于真实飞艇的方法的演示。我们已经在https://github.com/robot-pocepepon-group/airship-mpc上发布了所有源代码。可以在https://youtu.be/ihs0_vrd_kk上观看描述我们方法和结果的视频。

人类不断与日常对象互动以完成任务。为了了解这种相互作用，计算机需要从观察全身与场景的全身相互作用的相机中重建这些相互作用。由于身体和物体之间的阻塞，运动模糊，深度/比例模棱两可以及手和可抓握的物体零件的低图像分辨率，这是具有挑战性的。为了使问题可以解决，社区要么专注于互动的手，忽略身体或互动的身体，无视双手。 Grab数据集解决了灵活的全身互动，但使用基于标记的MOCAP并缺少图像，而行为则捕获了身体对象互动的视频，但缺乏手动细节。我们使用参数全身模型SMPL-X和已知的对象网格来解决一种新的方法，该方法与Intercap的先前工作局限性，该方法是一种新的方法，可重建从多视图RGB-D数据进行交互的整体和对象。为了应对上述挑战，Intercap使用了两个关键观察：（i）可以使用手和物体之间的接触来改善两者的姿势估计。 （ii）Azure Kinect传感器使我们能够建立一个简单的多视图RGB-D捕获系统，该系统在提供合理的相机间同步时最小化遮挡的效果。使用此方法，我们捕获了Intercap数据集，其中包含10个受试者（5名男性和5个女性）与10个各种尺寸和负担的物体相互作用，包括与手或脚接触。 Intercap总共有223个RGB-D视频，产生了67,357个多视图帧，每个帧包含6个RGB-D图像。我们的方法为每个视频框架提供了伪真正的身体网格和对象。我们的Intercap方法和数据集填补了文献中的重要空白，并支持许多研究方向。我们的数据和代码可用于研究目的。

SMPL（SMPL）的参数3D身体模型仅代表最小衣服的人，并且很难扩展到衣服，因为它们具有固定的网格拓扑和分辨率。为了解决这些局限性，最近的工作使用隐式表面或点云来建模衣服。虽然不受拓扑的限制，但这种方法仍然很难为偏离身体的偏离的衣服建模，例如裙子和连衣裙。这是因为他们依靠身体来通过将衣服表面放置为参考形状。不幸的是，当衣服远离身体时，这个过程的定义很差。此外，他们使用线性混合剥皮来摆姿势，并将皮肤重量与下面的身体部位绑在一起。相比之下，我们在没有规范化的情况下对局部坐标空间中的衣服变形进行了建模。我们还放松皮肤重量以使多个身体部位影响表面。具体而言，我们用粗糙的阶段扩展了基于点的方法，该方法用学习的姿势独立的“粗大形状”代替了规范化，该方法可以捕获裙子（如裙子）的粗糙表面几何形状。然后，我们使用一个网络来完善该网络，该网络会渗透到粗糙表示中的线性混合剥皮权重和姿势依赖的位移。该方法适合符合身体并偏离身体的服装。我们通过从示例中学习特定于人的化身，然后展示如何以新的姿势和动作来展示它们的有用性。我们还表明，该方法可以直接从原始扫描中学习缺少数据，从而大大简化了创建逼真的化身的过程。代码可用于研究目的，可在{\ small \ url {https://qianlim.github.io/skirt}}中使用。