Spatial drawing using ruled-surface brush strokes is a popular mode of content creation in immersive VR, yet little is known about the usability of existing spatial drawing interfaces or potential improvements. We address these questions in a three-phase study. (1) Our exploratory need-finding study (N=8) indicates that popular spatial brushes require users to perform large wrist motions, causing physical strain. We speculate that this is partly due to constraining users to align their 3D controllers with their intended stroke normal orientation. (2) We designed and implemented a new brush interface that significantly reduces the physical effort and wrist motion involved in VR drawing, with the additional benefit of increasing drawing accuracy. We achieve this by relaxing the normal alignment constraints, allowing users to control stroke rulings, and estimating normals from them instead. (3) Our comparative evaluation of StripBrush (N=17) against the traditional brush shows that StripBrush requires significantly less physical effort and allows users to more accurately depict their intended shapes while offering competitive ease-of-use and speed.

中文翻译：

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StripBrush：一种约束放松的 3D 画笔，可减少体力并提高空间绘图质量

使用直纹表面笔触进行空间绘制是沉浸式 VR 中一种流行的内容创建模式，但对现有空间绘制界面的可用性或潜在改进知之甚少。我们在三阶段研究中解决了这些问题。(1) 我们的探索性需求发现研究 (N=8) 表明流行的空间画笔需要用户进行大的手腕运动，从而导致身体疲劳。我们推测这部分是由于限制用户将他们的 3D 控制器与他们预期的笔画法线方向对齐。(2) 我们设计并实现了一个新的画笔界面，显着减少了 VR 绘图中涉及的体力和手腕运动，并具有提高绘图准确性的额外好处。我们通过放宽正常对齐约束来实现这一点，允许用户控制笔画规则，并从它们估计法线。(3) 我们对 StripBrush (N=17) 与传统画笔的比较评估表明，StripBrush 需要的体力显着减少，并且允许用户更准确地描绘他们想要的形状，同时提供具有竞争力的易用性和速度。