MR.Sketch. Immediate 3D Sketching via Mixed Reality Drawing Canvases

Sketching is a fundamental technique for early design and form finding. Digital 3D sketching can improve the early design phase by improving spatial understanding and enriching the design with additional information. However, the tools used for sketching should not hinder the expression and thought process inherent in form finding. Methods already exist for using 2D pen-on-tablet input for 3D sketching via stroke projection onto 3D drawing canvases. However, positioning the canvas and sketching lines are separate work steps. This breaks the flow of the designer's thought process. We propose a novel technique for mixed reality 3D sketching that involves the use of viewport-attached drawing canvases, spatial meshing and intersection canvas visualisation. By combining the inside-out tracking capabilities of current portable consumer devices with stylus-on-tablet freehand drawing input, we transform 2D to 3D projective sketching into a more seamless experience. Results of a pilot user study with 16 participants show significant user preference for our technique, as well as increased sketching speed and immediacy.