click to play button
click to replay button
slider_variable_increasing_once_captions
X
    00:00 / 00:00
    CC
    In this screencast we are going to show how to
    effectively use the slider option for repeating
    “increasing once”. So what is that?
    That is an option where the animation will go from
    t-=0 to the endpoint exactly once. But there are a
    few things to consider.
    First let us see what we want. Let us say that
    we want the man to walk from 0 to 4 or
    whatever the distance d is.
    So let us put a picture of a man. Insert image. This
    is one little tiny tip. If we come down here, both
    points P and A glow.
    So we can either move t over to get P by itself or
    we can click over here in the Algebra view to get
    P by itself. Okay.
    There is my man image. Insert. Now if we turn the
    animation on the man goes with the point P.
    Now what happens if we change the animation
    to be the repeat “increasing once”?
    Right-click, go down to object properties, on the
    slider tab, we see the repeat and we will change
    it to “increasing once”.
    Now that sounds great. Let us turn it on. What
    happens? The man goes to the endpoint and then
    the play button is no longer there.
    Okay. Then you have to right-click and all this
    other stuff to get it to animate again. So how do
    we fix this so that it works really great?
    We will insert a button that says “Animate”. So
    animate is our button name.
    Now the first thing we want to do is reset - this
    is script, but it is nothing difficult. Reset our slider
    to 0 so t=0.
    And then hit Enter and then we say
    startanimation (all one word) and then it is best if
    we put the variable in there.
    So bracket, then “t”, then close bracket. That is it.
    t=0 and startanimation. Apply. Let us get our Move
    tool and try it.
    Animate. Now we can pause it down here and
    then restart down here, but will go exactly once
    and if we want it to start it again, we can start it
    again with the Animate button.
    Now another thing that is nice – remember in the
    last video we showed that if we right-click on d
    and we say “scripting” and we told it t=0.
    Probably the best thing would be to have it stop
    the animation first. So we go to the front. Hit
    enter.
    BTW there is no stopanimation command. But we
    type startanimation and we tell it [false] and that
    is actually “stop animation”.
    So startanimation[false] and then t=0 so it resets
    it. Now don’t forget to do this. You must come
    down here and find OK and then click Close.
    Now if our animation is on and we change the
    value of d, it will reset and stop and wait for us to
    animate again.
    Here is another example of a worksheet where
    the animation on the slider t is “increasing once”.
    It has a variable length - the length of this arc.
    The animation button rolls out the arc and on the
    radius, the angle and the reset button is the
    simple scripting: startanimation[false] and t=0.
    So I can reset here and look at it before rolling it
    out again. If I start to roll out and I change the
    angle.
    Notice the animation stopped and t=0 again. And
    then roll out again. If I change the radius, again it
    stops and resets.
    So on all 3 of these we have that scripting
    startanimation[false], t=0 and on the slider itself
    we have used the repeat “increasing once”.