Model Exercise 1

Few days ago, I browsed the the hotel and hospitality websites to look for a typical movement and i find it's hard to seek one, especially mine is a hotel complex. I then brainstormed some possible activities in a hotel COMPLEX. Finally, i set the music performance in lounge bar and clubs as my target movement and take the movement of bowing by violinist 's right hand. I trace the joints of the violinist's arm to inspect the movement vectors, such as directions, angles and muscle relationships.


A diagram of the movement pattern generated by the joints and vectors. The mathematical functions are produced by the points on each body joint. The shoulder joint us set ti be fixed and the rotating angle of the shoulder joint is no more than 90 deg. in bowing movement. The angles of the elbow and wrist joints are set no more than 180 deg. Therefore, the sin and cos curves are applied in two functions to describe the absolute position of Point (xP,yP) on the violin bow.

Let r is length of arm, t is shoulder angle, t1 is elbow angle, x2 is x value of bow point and y2 is y value of bow point,

x2=2rt+r[1-Sin(t)]


y2=r[1-Cos(t)]+r[Cos(t1)]




I considered the music tempo for violinists. In the position of the bow on the E String, the fixed value input of r is 300 and i set a angle of 5 deg. for t and t1.

The result curve is:

After that, I enter 3 and 4 as t and t1 to simulate the the position of the bow on the other three strings. After that, there were 4 curves generated in total and then I applied loft functino in Rhino a model represent the movement of a single point on the bow. The final curve showing the general movement of the violinist's bowing movement in playing a range of music pieces.