近幾年智慧型手機快速普及，成為生活中不可或缺的工具之一。因為其具有高攜帶性與便利性等優點，能夠提供新型態的與三維模型互動的操作方式。
我們以智慧型手機為控制裝置，利用手勢操作設計一套快速、容易上手的三維模型操作介面，並且能控制九個維度的參數(三維移動、三維旋轉、三維形變)，以及透過內建陀螺儀實現的自由旋轉模型操作。
在我們的設計中，使用者以雙手把持手機進行操作。
使用單指或雙指的手勢，即可對模型進行相對應的操作，例如：移動、旋轉、型變等。
使用雙手任意旋轉手機，畫面中的模型也會產生相同地旋轉，就像把模型拿在手中般。
此外，我們也針對了在操作時可能會遇到的「Ambiguity」問題進行研究，並且實作了「動態攝影機」進行輔助，解決Ambiguity問題。
讓使用者在操作的過程中，不會因此受到阻礙或產生錯誤的操作。
最後，根據使用者測試的結果顯示，使用我們的介面完成實驗所花費的時間遠少於傳統鍵盤滑鼠介面。
並且大部份的實驗者都給予我們的介面正面的評價。

The popularity of portable and handy smartphones offers a great potential for new forms of interaction with virtual 3D contents.
We present the design of {\EZM}, a new 3D manipulation interface on smartphones that provides mobile, fast and ambiguity-free 9DOF (nine Degrees of Freedom) axis-constrained manipulations and free-form rotation using the multitouch inputs and gyroscope sensor.
In our design, users benefit from the handiness of smartphones, while being able to manipulate the 3D objects easily at both fine-grained and coarse levels using respectively intuitive single- or two-finger gestures and rotating the device in hand(s).
We further investigate the ambiguous manipulation problems introduced by multitouch-based indirect manipulations, and proposed a dynamic adjustment of virtual camera to effectively resolve the ambiguity.
A preliminary study reports that our interface has significant lower task completion times in comparison to conventional keyboard-mouse interface, and gains positive user experience from both novices and experts.

[1] O. K.-C. Au, C.-L. Tai, and H. Fu. Multitouch gestures for constrained transforma- tion of 3d objects. In Computer Graphics Forum (2012), volume 31, pages 651–660.
[2] D. Baur, S. Boring, and S. Feiner. Virtual projection: Exploring optical projection as a metaphor for multi-device interaction. In ACM CHI ’12 (2012), pages 1693–1702.
[3] E. A. Bier. Skitters and jacks: Interactive 3d positioning tools. In I3D ’86 (1987), pages 183–196.
[4] S. Boring, D. Baur, A. Butz, S. Gustafson, and P. Baudisch. Touch projector: Mobile interaction through video. In ACM CHI ’10 (2010), pages 2287–2296.
[5] S. Boring, S. Gehring, A. Wiethoff, A. M. Blo ̈ckner, J. Scho ̈ning, and A. Butz. Multi-user interaction on media facades through live video on mobile devices. In ACM CHI ’11 (2011), pages 2721–2724.
[6] M. Chen, S. J. Mountford, and A. Sellen. A study in interactive 3-d rotation using 2-d control devices. In ACM SIGGRAPH ’88 (1988), pages 121–129.
[7] A. Cohe ́, F. De`cle, and M. Hachet. tbox: A 3d transformation widget designed for touch-screens. In ACM CHI ’11 (2011), pages 3005–3008.
[8] B. D. Conner, S. S. Snibbe, K. P. Herndon, D. C. Robbins, R. C. Zeleznik, and A. van Dam. Three-dimensional widgets. In Proceedings of the 1992 Symposium on Interactive 3D Graphics, I3D ’92, pages 183–188. ACM, 1992.
[9] B. Froehlich, J. Hochstrate, V. Skuk, and A. Huckauf. The globefish and the globe- mouse: Two new six degree of freedom input devices for graphics applications. In ACM CHI ’06 (2006), pages 191–199.
[10] M. Hachet, B. Bossavit, A. Cohe ́, and J.-B. de la Rivie`re. Toucheo: Multitouch and stereo combined in a seamless workspace. In ACM UIST ’11 (2011), pages 587–592.
[11] M. Hachet, F. Decle, S. Knodel, and P. Guitton. Navidget for easy 3d camera posi- tioning from 2d inputs. In 3DUI (2008), pages 83–89.
[12] M.Hancock,S.Carpendale,andA.Cockburn.Shallow-depth3dinteraction:Design and evaluation of one-, two- and three-touch techniques. In ACM CHI ’07 (2007), pages 1147–1156.
[13] M. Hancock, T. ten Cate, and S. Carpendale. Sticky tools: Full 6dof force-based interaction for multi-touch tables. In ITS ’09 (2009), pages 133–140.
[14] K. Henriksen, J. Sporring, and K. Hornbæk. Virtual trackballs revisited. In IEEE TVCG (2004), pages 206–216.
[15] O. Hilliges, D. Kim, S. Izadi, M. Weiss, and A. Wilson. Holodesk: Direct 3d interac- tions with a situated see-through display. In ACM CHI ’12 (2012), pages 2421–2430.
[16] K. Hinckley, R. Pausch, J. C. Goble, and N. F. Kassell. Passive real-world interface props for neurosurgical visualization. In ACM CHI ’94 (1994), pages 452–458. ACM, 1994.
[17] J. Kashiwakuma, I. Kitahara, Y. Kameda, and Y. Ohta. A virtual camera controlling method using multi-touch gestures for capturing free-viewpoint video. In EuroITV ’13( 2013), pages 67–74.
[18] Katzakis, H. Nicholas, and Masahiro. Mobile devices as multi-dof controllers. In 3DUI(2010), pages 139–140. IEEE, 2010.
[19] K. Kin, T. Miller, B. Bollensdorff, T. DeRose, B. Hartmann, and M. Agrawala. Eden: A professional multitouch tool for constructing virtual organic environments. In ACM CHI ’11 (2011), pages 1343–1352.
[20] J. Liu, O. K.-C. Au, H. Fu, and C.-L. Tai. Two-finger gestures for 6dof manipulation of 3d objects. In Computer Graphics Forum (2012), volume 31, pages 2047–2055.
[21] A. Martinet, G. Casiez, and L. Grisoni. The effect of dof separation in 3d manipu- lation tasks with multi-touch displays. In VRST ’10 (2010), pages 111–118.
[22] A. Martinet, G. Casiez, and L. Grisoni. Integrality and separability of multitouch interaction techniques in 3d manipulation tasks. In IEEE TVCG (2012), pages 369– 380.
[23] Microsoft. Hololens.
[24] Oculus. Rift.
[25] P. Paczkowski, J. Dorsey, H. Rushmeier, and M. H. Kim. Paper3d: Bringing casual 3d modeling to a multi-touch interface. In ACM UIST ’14 (2014), pages 23–32.
[26] G. Perelman, M. Serrano, M. Raynal, C. Picard, M. Derras, and E. Dubois. The roly-poly mouse: Designing a rolling input device unifying 2d and 3d interaction. In ACM CHI ’15 (2015), 2015.
[27] J. L. Reisman, P. L. Davidson, and J. Y. Han. A screen-space formulation for 2d and 3d direct manipulation. In ACM UIST ’09 (2009), pages 69–78.
[28] R. Schmidt, K. Singh, and R. Balakrishnan. Sketching and composing widgets for 3d manipulation. In Computer Graphics Forum (2008), volume 27, pages 301–310.
[29] R. S. Sodhi, B. R. Jones, D. Forsyth, B. P. Bailey, and G. Maciocci. Bethere: 3d mobile collaboration with spatial input. In ACM CHI ’13 (2013), pages 179–188.
[30] P. Song, W. B. Goh, W. Hutama, C.-W. Fu, and X. Liu. A handle bar metaphor for virtual object manipulation with mid-air interaction. In ACM CHI ’12 (2012), pages 1297–1306.
[31] S. Strothoff, D. Valkov, and K. Hinrichs. Triangle cursor: Interactions with objects above the tabletop. In ITS ’11 (2011), pages 111–119.
[32] Q. Sun, J. Lin, C.-W. Fu, S. Kaijima, and Y. He. A multi-touch interface for fast architectural sketching and massing. In ACM CHI ’13 (2013), pages 247–256.
[33] R. Wang, S. Paris, and J. Popovic ́. 6d hands: Markerless hand-tracking for computer aided design. In ACM UIST ’11 (2011), pages 549–558.
[34] R. Y. Wang and J. Popovic ́. Real-time hand-tracking with a color glove. In ACM SIGGRAPH ’09 (2009), pages 63:1–63:8.
[35] C. Ware and D. R. Jessome. Using the bat: A six dimensional mouse for object placement. In GI ’88 (1988), pages 119–124.
[36] T.G.Zimmerman,J.Lanier,C.Blanchard,S.Bryson,andY.Harvill.Ahandgesture interface device. In ACM CHI ’87 (1987), pages 189–192.