The given model consists of 6 parts:
a. Shoulder
b. Arm
c. Elbow
d. Fore-arm
e. Wrist
f. alm
The model is made of two parts:
The joints, i.e. the shoulder, elbow and wrist are just empty containers that contain other objects
nested within them. Shoulder is at the highest level of hierarchy (Level 1), containing arm and
elbow as its children. Elbow is 2nd level, containing Forearm and Wrist as its children. Finally,
wrist, at Level 3, has palm as its child.
When transformations are applied to an object at a higher level of hierarchy, the animations are
applied to its descendants as well.
Therefore, in this case, when the slider corresponding to shoulder (level 1) is moved, all the
objects (levels 1, 2 and 3) are moved. Similarly, when the slider corresponding to elbow is moved,
objects in levels 2 and 3 move.
We can observe the values of the transformation matrix changing with change in the position of the
slider. This is the matrix with which the point’s homogeneous coordinates are multiplied to generate
the new coordinates (that produces the scaling effect).
We can move the slider forwards and backwards any number of times, change the no. of frames and the
scaling factors in the X, Y and Z directions in between as well. The slider and animation adjusts
itself accordingly.
You can add new shapes by clicking on the “Add” button with options to select the type of shape and
position. Multiple shapes may be added.
Double click on the object to select it and enable the edit and delete buttons. Clicking on the edit
button allows you to edit the object’s properties. Similarly, clicking on the delete button deletes
the selected object.
Check the corresponding checkboxes to display the xy-grid, yz-grid and xz-grid and similarly uncheck
to remove them from view.
Enabling the Lock Vertices option allows you to translate the whole simulation on left-clicking and
dragging the cursor.