Mid-Air Drawing of Curves on 3D Surfaces in Virtual Reality

TL;DR

This paper investigates the problem of accurately projecting mid-air drawn curves onto 3D surfaces in VR, introducing and evaluating novel techniques to improve user experience and drawing precision.

Contribution

It provides the first detailed analysis of 3D stroke projection in VR, proposing and empirically evaluating a new stroke mimicry algorithm for better surface curve drawing.

Findings

Stroke mimicry is preferred by users over other techniques.

The proposed method enables precise and efficient 3D curve drawing on surfaces.

The approach supports artistic and functional design applications in VR.

Abstract

Complex 3D curves can be created by directly drawing mid-air in immersive environments (Augmented and Virtual Realities). Drawing mid-air strokes precisely on the surface of a 3D virtual object, however, is difficult; necessitating a projection of the mid-air stroke onto the user "intended" surface curve. We present the first detailed investigation of the fundamental problem of 3D stroke projection in VR. An assessment of the design requirements of real-time drawing of curves on 3D objects in VR is followed by the definition and classification of multiple techniques for 3D stroke projection. We analyze the advantages and shortcomings of these approaches both theoretically and via practical pilot testing. We then formally evaluate the two most promising techniques spraycan and mimicry with 20 users in VR. The study shows a strong qualitative and quantitative user preference for our novel stroke mimicry projection algorithm. We further illustrate the effectiveness and utility of stroke mimicry, to draw complex 3D curves on surfaces for various artistic and functional design applications.