We introduce RealityCanvas, a mobile AR sketching tool that can easily augment real-world physical motion with responsive hand-drawn animation. Recent research in AR sketching tools has enabled users to not only embed static drawings into the real world but also dynamically animate them with physical motion. However, existing tools often lack the flexibility and expressiveness of possible animations, as they primarily support simple line-based geometry. To address this limitation, we explore both expressive and improvisational AR sketched animation by introducing a set of responsive scribble animation techniques that can be directly embedded through sketching interactions: 1) object binding, 2) flip-book animation, 3) action trigger, 4) particle effects, 5) motion trajectory, and 6) contour highlight. These six animation effects were derived from the analysis of 172 existing video-edited scribble animations. We showcase these techniques through various applications, such as video creation, augmented education, storytelling, and AR prototyping. The results of our user study and expert interviews confirm that our tool can lower the barrier to creating AR-based sketched animation, while allowing creative, expressive, and improvisational AR sketching experiences.

翻译：我们提出RealityCanvas，一款移动增强现实草图绘制工具，可轻松将真实世界的物理运动与响应式手绘动画相结合。近期关于AR草图工具的研究已使用户不仅能将静态绘制嵌入现实世界，还能使其随物理运动动态呈现。然而现有工具多局限于简单线性几何图形，缺乏动画创作的灵活性与表现力。为突破此局限，我们通过引入六种可直接嵌入草图交互的响应式涂鸦动画技术，探索兼具表现力与即兴性的AR草图动画：1）对象绑定、2）翻书动画、3）动作触发、4）粒子特效、5）运动轨迹、6）轮廓高亮。这六种动画效果源自对172个现有视频编辑涂鸦动画的分析。我们通过视频创作、增强教育、叙事表达及AR原型设计等多种应用场景展示了这些技术。用户研究与专家访谈结果表明，本工具能降低AR草图动画创作门槛，同时提供富有创意性、表现力与即兴性的AR草图绘制体验。