Posing 3D Models from Drawing

Inferring the 3D pose of a character from a drawing is a complex and under-constrained problem. Solving it may help automate various parts of an animation production pipeline such as pre-visualisation. In this paper, a novel way of inferring the 3D pose from a monocular 2D sketch is proposed. The proposed method does not make any external assumptions about the model, allowing it to be used on different types of characters. The inference of the 3D pose is formulated as an optimisation problem and a parallel variation of the Particle Swarm Optimisation algorithm called PARAC-LOAPSO is utilised for searching the minimum. Testing in isolation as well as part of a larger scene, the presented method is evaluated by posing a lamp, a horse and a human character. The results show that this method is robust, highly scalable and is able to be extended to various types of models

Sketch2Pose : estimating a 3D character pose from a bitmap sketch

Artists frequently capture character poses via raster sketches, then use these drawings as a reference while posing a 3D character in a specialized 3D software --- a time-consuming process, requiring specialized 3D training and mental effort. We tackle this challenge by proposing the first system for automatically inferring a 3D character pose from a single bitmap sketch, producing poses consistent with viewer expectations. Algorithmically interpreting bitmap sketches is challenging, as they contain significantly distorted proportions and foreshortening. We address this by predicting three key elements of a drawing, necessary to disambiguate the drawn poses: 2D bone tangents, self-contacts, and bone foreshortening. These elements are then leveraged in an optimization inferring the 3D character pose consistent with the artist's intent. Our optimization balances cues derived from artistic literature and perception research to compensate for distorted character proportions. We demonstrate a gallery of results on sketches of numerous styles. We validate our method via numerical evaluations, user studies, and comparisons to manually posed characters and previous work

Human motion retrieval based on freehand sketch

In this paper, we present an integrated framework of human motion retrieval based on freehand sketch. With some simple rules, the user can acquire a desired motion by sketching several key postures. To retrieve efficiently and accurately by sketch, the 3D postures are projected onto several 2D planes. The limb direction feature is proposed to represent the input sketch and the projected-postures. Furthermore, a novel index structure based on k-d tree is constructed to index the motions in the database, which speeds up the retrieval process. With our posture-by-posture retrieval algorithm, a continuous motion can be got directly or generated by using a pre-computed graph structure. What's more, our system provides an intuitive user interface. The experimental results demonstrate the effectiveness of our method. © 2014 John Wiley & Sons, Ltd

Interactive Sketching of Mannequin Poses

It can be easy and even fun to sketch humans in different poses. In contrast, creating those same poses on a 3D graphics 'mannequin' is comparatively tedious. Yet 3D body poses are necessary for various downstream applications. We seek to preserve the convenience of 2D sketching while giving users of different skill levels the flexibility to accurately and more quickly pose/refine a 3D mannequin. At the core of the interactive system, we propose a machine-learning model for inferring the 3D pose of a CG mannequin from sketches of humans drawn in a cylinder-person style. Training such a model is challenging because of artist variability, a lack of sketch training data with corresponding ground truth 3D poses, and the high dimensionality of human pose-space. Our unique approach to synthesizing vector graphics training data underpins our integrated ML-and-kinematics system. We validate the system by tightly coupling it with a user interface, and by performing a user study, in addition to quantitative comparisons

The Line of Action: an Intuitive Interface for Expressive Character Posing

International audienceThe line of action is a conceptual tool often used by cartoonists and illustrators to help make their figures more consistent and more dramatic. We often see the expression of characters--may it be the dynamism of a super hero, or the elegance of a fashion model--well captured and amplified by a single aesthetic line. Usually this line is laid down in early stages of the drawing and used to describe the body's principal shape. By focusing on this simple abstraction, the person drawing can quickly adjust and refine the overall pose of his or her character from a given viewpoint. In this paper, we propose a mathematical definition of the line of action (LOA), which allows us to automatically align a 3D virtual character to a user specified LOA by solving an optimization problem. We generalize this framework to other types of lines found in the drawing literature, such as secondary lines used to place arms. Finally, we show a wide range of poses and animations that were rapidly created using our system

Character customization: Animated hair and clothing

Treball final de Grau en Disseny i Desenvolupament de Videojocs. Codi: VJ1241. Curs acadèmic: 2018/2019This project consists in designing and implementing a 3D female character editor. It is focused in modeling and animating the female character, hairstyle and clothes. This editor will be developed using the Unity 3D Game Engine. It will consist in an interface that allows changing skin and eye color, style and color of hair and, lastly, the clothes the character is to wear among a catalogue of predefined models. With each change, the character will respond with an animation in order to improve the experience of perceiving the final style of the character

3D storyboarding for modern animation.

Animation is now a classic medium that has been practiced for over a century. While Disney arguably made it mainstream with some hand-drawn classics, today’s industry is focused on Three-Dimensional (3D) animation. In modern 3D animation productions, there have been significant leaps in terms of optimising, automating and removing manual tasks. This has allowed the artistic vision to be realised within time and budget and empowered artists to do things that in the past would be technically more difficult. However, most existing research is focused on specific tasks or processes rather than the pipeline itself. Moreover, it is mostly focused on elements of the animation production phase, such as modelling, animating and rendering. As a result, pre-production parts like storyboarding are still done in the traditional way, often drawn by hand. Because of this disparity between the old and the new, the transition from storyboarding to 3D is prone to errors. 3D storyboarding is an attempt to adapt the pre-production phase of modern animation productions. By allowing storyboard artists access to simple but scale-accurate 3D models early on, drawing times as well as transition times between pre-production and production can be reduced. However, 3D storyboarding comes with its own shortcomings. By analysing existing pipelines, points of potential improvement are identified. Motivating research from these points, alternative workflows, automated methods and novel ideas that can be combined to make 3D animation pipelines more efficient are presented. The research detailed in this thesis focuses on the area between pre-production and production. A pipeline is presented that consists of a portfolio of projects that aim to: • Generate place-holder character assets from a drawn character line-up • Create project files with scene and shot breakdowns using screenplays • Empower non-experts to pose 3D characters using Microsoft Kinect • Pose 3D assets automatically by using 2D drawings as input

Evaluating consumer interaction interfaces for 3D sketching in virtual reality

Since its introduction, 3D mid-air sketching in immersive Virtual Reality (VR) proved to be a very powerful tool for many creative applications. However, common VR sketching suites rely on the standard hand controllers bundled with home VR systems, which are non-optimal for this kind of tasks. To deal with this issue, some research works proposed to use dedicated pen-shaped interfaces tracked with external motion-capture systems. Regrettably, these solutions are generally rather expensive, cumbersome and unsuitable for many potential end- users. Hence, lots of challenges regarding interfaces for 3D sketching in VR still exist. In this paper, a newly proposed sketching-oriented input device (namely, a VR stylus) compatible with the tracking technology of a consumer-grade VR system is compared with a standard hand con- troller from the same system. In particular, the paper reports the results of a user study whose aim was to evaluate, in both objective and subjective terms, aspects like, among others, sketching accuracy, ease of use, efficiency, comfort, control and naturalness

Space-time sketching of character animation

International audienceWe present a space-time abstraction for the sketch-based design of character animation. It allows animators to draft a full coordinated motion using a single stroke called the space-time curve (STC). From the STC we compute a dynamic line of action (DLOA) that drives the motion of a 3D character through projective constraints. Our dynamic models for the line's motion are entirely geometric, require no pre-existing data, and allow full artistic control. The resulting DLOA can be refined by over-sketching strokes along the space-time curve, or by composing another DLOA on top leading to control over complex motions with few strokes. Additionally , the resulting dynamic line of action can be applied to arbitrary body parts or characters. To match a 3D character to the 2D line over time, we introduce a robust matching algorithm based on closed-form solutions, yielding a tight match while allowing squash and stretch of the character's skeleton. Our experiments show that space-time sketching has the potential of bringing animation design within the reach of beginners while saving time for skilled artists

Spatial Motion Doodles: Sketching Animation in VR Using Hand Gestures and Laban Motion Analysis

International audienceWe present a method for easily drafting expressive character animation by playing with instrumented rigid objects. We parse the input 6D trajectories (position and orientation over time)-called spatial motion doodles-into sequences of actions and convert them into detailed character animations using a dataset of parameterized motion clips which are automatically fitted to the doodles in terms of global trajectory and timing. Moreover, we capture the expres-siveness of user-manipulation by analyzing Laban effort qualities in the input spatial motion doodles and transferring them to the synthetic motions we generate. We validate the ease of use of our system and the expressiveness of the resulting animations through a series of user studies, showing the interest of our approach for interactive digital storytelling applications dedicated to children and non-expert users, as well as for providing fast drafting tools for animators