T-FLEX Parametric CAD. Fundamentals. 2D Design

Fundamentals. Two-Dimensional Design
Example: Clock Ticking Animation
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A simple and instructive example of using animation for
simulating a mechanism motion can be a model of a
clock. This model is provided with the library
“Documentation samples”, the folder “\2D
Design\Animation\Watch\”. The model
contains an animation screenplay, modeling a working
clock: moving arms and changing date.
To animate the model, the variables “a” and “Date” are
introduced. The variable “a” defines the current time in
seconds (it will drive the position of the clock arms),
while the “Date” variable – the figure displayed in the
date dial of the clock.
The clock arms and the date dial are 3D fragments.
Since the arms are supposed to rotate in the animation,
each arm fragment has an angle parameter defining the
angle of rotation with respect to the Z axis via an
expression dependent on the variable “a”: for the
seconds arm it is “-6*a”, for the minutes one - “-a/10”,
and for the hours – “-a/120”.
The date dial fragment must update the displayed figures
during the animation. For this purpose, an external
variable “Date” is created in the fragment, defining the
numeric figures in the fragment. Upon assembling the
fragment, this variable is commanded by its namesake in
the assembly.
The animation is supposed to simulate the time from
23: 55 to 0:01. During the animation, besides the arms
motion, the date shall change on the date dial (at the
midnight).
Therefore, two independent variables, “a” and “Date”,
shall vary their values. The model is “animated” by the
“Animation Screenplay” application, taking into the
account this mentioned feature.
The “Clock” animation screenplay uses the variation diagrams for the variables “a” and “Date”. The
animation time interval T is assumed from 0 (5 minutes before midnight) to 360(1 minute of the midnight).
The time T=300 corresponds to the midnight, that is the moment of changing date. The variable diagrams are
created according to the following tabulated values:
T 0 300 360
a, 0
-300 0 60
T 0 300 360
Date 31 31/1 1