Virtual reality is becoming increasingly popular, and modern haptic equipment, such as vibrotactile suits, haptic gloves, and force-feedback controllers, offers new means of interaction within virtual environments, significantly enhancing user experience. When interacting with virtual objects, combined visual and haptic feedback simulates the physical sensations of grasping, lifting, or moving real objects. This sensorimotor feedback is essential for inducing a sense of presence and agency, yet it remains challenging to reproduce in the absence of reliable haptic cues. In this study, we design and evaluate several haptic metaphors using combinations of vibrotactile design parameters to simulate the lifting effort associated with light to heavy objects. These parameters include primitive signals, intensity, spatial density, propagation, and temporal density. Our contribution is threefold. First, we propose a method for modulating perceived physical effort by extending signal intensity with spatial and temporal density, which together reflect the effort required to lift an object. Second, we present a user study in which participants compared haptic effects and ranked them according to perceived lifting effort, comfort, and confidence, allowing us to assess the influence of each parameter. Third, we report the results of a second study in which participants evaluated vibrotactile effects when lifting different virtual objects. The findings confirm the importance of intensity and spatial density, as well as the influence of graphical representation on perceived effort. This research provides practical insights for designing haptic-enabled virtual reality systems and offers guidance for developers seeking to create more expressive and believable vibrotactile interactions.

This paper presents a demonstration showcasing the capabilities of the upcoming MPEG-I standards on Haptics and Scene Description. The demonstration is a sensorial immersive experience using a virtual reality headset, haptic-enabled controllers and a haptic vest. The proposed experience is an interactive go-kart race-like game where interactions with the environment will trigger spatialized haptic feedback to provide an enhanced sense of immersion. By implementing the MPEG-I standards on Haptics and Scene Description, and by designing this demonstration using exclusively these standards, this work showcases part of the research and standardization efforts produced through the MPEG ecosystem.

Research in virtual cinematography often narrows the problem down to computing the optimal viewpoint for the camera to properly convey a scene’s content. In contrast we propose to address simultaneously the questions of placing cameras, lights, objects and actors in a virtual environment through a high-level specification. We build on a staging language and propose to extend it by defining complex temporal relationships between these entities. We solve such specifications by designing pruning operators which iteratively reduce the range of possible degrees of freedom for entities while satisfying temporal constraints. Our solver first decomposes the problem by analyzing the graph of relationships between entities and then solves an ordered sequence of sub-problems. Users have the possibility to manipulate the current result for fine-tuning purposes or to creatively explore ranges of solutions while maintaining the relationships. As a result, the proposed system is the first staging-and-shooting cinematography system which enables the specification and solving of spatio-temporal cinematic layouts.

Creatives in animation and film productions have forever been exploring the use of new means to prototype their visual sequences before realizing them, by relying on hand-drawn storyboards, physical mockups or more recently 3D modelling and animation tools. However these 3D tools are designed in mind for dedicated animators rather than creatives such as film directors or directors of photography and remain complex to control and master. In this paper we propose a VR authoring system which provides intuitive ways of crafting visual sequences, both for expert animators and expert creatives in the animation and film industry. The proposed system is designed to reflect the traditional process through (i) a storyboarding mode that enables rapid creation of annotated still images, (ii) a previsualisation mode that enables the animation of the characters, objects and cameras, and (iii) a technical mode that enables the placement and animation of complex camera rigs (such as cameras cranes) and light rigs. Our methodology strongly relies on the benefits of VR manipulations to re-think how content creation can be performed in this specific context, typically how to animate contents in space and time. As a result, the proposed system is complimentary to existing tools, and provides a seamless back-and-forth process between all stages of previsualisation. We evaluated the tool with professional users to gather experts' perspectives on the specific benefits of VR in 3D content creation.

Abstract The placement of lights in a 3D scene is a technical and artistic task that requires time and trained skills. Most 3D modelling tools only provide a direct control of light sources, through the manipulation of parameters such as size, location, flux (the perceived power of light) or opening angle (the light frustum). Approaches have been relying on automated or semi‐automated techniques to relieve users from such low‐level manipulations at the expense of an important computational cost. In this paper, guided by discussions with experts in scene and object lighting, we propose an indirect control of area light sources. We first formalize the classical 3‐point lighting design principle (key‐light, fill‐lights and back/rim‐lights) in a parametric model. Given a key‐light placed in the scene, we then provide a computational approach to (i) automatically compute the position and size of fill‐lights and back/rim‐lights by analyzing the geometry of 3D character, and (ii) automatically compute the flux and size of key, fill and back/rim lights, given a sample reference image in a computationally efficient way. Results demonstrate the benefits of the approach on the quick lighting of 3D characters, and further demonstrate the feasibility of interactive control of multiple lights through image features.

Quadrotor drones equipped with high-quality cameras have rapidly raised as novel, cheap, and stable devices for filmmakers. While professional drone pilots can create aesthetically pleasing videos in short time, the smooth—and cinematographic—control of a camera drone remains challenging for most users, despite recent tools that either automate part of the process or enable the manual design of waypoints to create drone trajectories. This article moves a step further by offering high-level control of cinematographic drones for the specific task of framing dynamic targets. We propose techniques to automatically and interactively plan quadrotor drone motions in dynamic three-dimensional (3D) environments while satisfying both cinematographic and physical quadrotor constraints. We first propose the Drone Toric Space , a dedicated camera parameter space with embedded constraints, and derive some intuitive on-screen viewpoint manipulators. Second, we propose a dedicated path planning technique that ensures both that cinematographic properties can be enforced along the path and that the path is physically feasible by a quadrotor drone. At last, we build on the Drone Toric Space and the specific path planning technique to coordinate the motion of multiple drones around dynamic targets. A number of results demonstrate the interactive and automated capacities of our approaches on different use-cases.

We describe an optimization-based approach for automatically creating well-edited movies from a 3D animation. While previous work has mostly focused on the problem of placing cameras to produce nice-looking views of the action, the problem of cutting and pasting shots from all available cameras has never been addressed extensively. In this paper, we review the main causes of editing errors in literature and propose an editing model relying on a minimization of such errors. We make a plausible semi-Markov assumption, resulting in a dynamic programming solution which is computationally efficient. We also show that our method can generate movies with different editing rhythms and validate the results through a user study. Combined with state-of-the-art cinematography, our approach therefore promises to significantly extend the expressiveness and naturalness of virtual movie-making.

When creating real or computer graphics movies, the questions of how to layout elements on the screen, together with how to move the cameras in the scene are crucial to properly conveying the events composing a narrative. Though there is a range of techniques to automatically compute camera paths in virtual environments, none have seriously considered the problem of generating realistic camera motions even for simple scenes. Among possible cinematographic devices, real cinematographers often rely on camera rails to create smooth camera motions which viewers are familiar with. Following this practice, in this paper we propose a method for generating virtual camera rails and computing smooth camera motions on these rails. Our technique analyzes characters motion and user-defined framing properties to compute rough camera motions which are further refined using constrained-optimization techniques. Comparisons with recent techniques demonstrate the benefits of our approach and opens interesting perspectives in terms of creative support tools for animators and cinematographers.

This paper presents a system that generates cinematic replays for dialogue-based 3D video games. The system exploits the narrative and geometric information present in these games and automatically computes camera framings and edits to build a coherent cinematic replay of the gaming session. We propose a novel importance-driven approach to cinematic replay. Rather than relying on actions performed by characters to drive the cinematography (as in idiom-based approaches), we rely on the importance of characters in the narrative. We first devise a mechanism to compute the varying importance of the characters. We then map importances of characters with different camera specifications, and propose a novel technique that (i) automatically computes camera positions satisfying given specifications, and (ii) provides smooth camera motions when transitioning between different specifications. We demonstrate the features of our system by implementing three camera behaviors (one for master shots, one for shots on the player character, and one for reverse shots). We present results obtained by interfacing our system with a full-fledged serious game (Nothing for Dinner) containing several hours of 3D animated content.

The automated computation of appropriate viewpoints in complex 3D scenes is a key problem in a number of computer graphics applications. In particular, crowd simulations create visually complex environments with many simultaneous events for which the computation of relevant viewpoints remains an open issue. In this paper, we propose a system which enables the conveyance of events occurring in complex crowd simulations. The system relies on Reynolds' model of steering behaviors to control and locally coordinate a collection of camera agents similar to a group of reporters. In our approach, camera agents are either in a scouting mode, searching for relevant events to convey, or in a tracking mode following one or more unfolding events. The key benefit, in addition to the simplicity of the steering rules, holds in the capacity of the system to adapt to the evolving complexity of crowd simulations by self-organizing the camera agents to track interesting events.