Object Width Animation

I know how to bind an objects width to a Timer value to make the object width change. Great, kind’a

Changing the width value only makes the object appear to grow from the Left to Right. How do you change the anchor point of the object so it changes width (grows) from Right to Left, or even from the center out?

The next step after this is to affect the timer value that the width is bound to.
The timer counts from 0 to X, then resets to 0.
I would need to have value ramp from 0 to x then ramp back down to 0. Can this be done by configuring the timer object or will I need to write a custom expression?


The reason for this post is because I want to make an object look like a mixer propeller spin in the Z plane.

This will require an object to grow from the center out and then shrink back to the center.

So far I have accomplished this us a signal generator (the Microwave looking thingy) set to a sine wave form.
I created an object that looks like a tear drop laid on its side, then duplicated it and mirrored the copy horizontally. The end result looks like a bow tie or figure 8 on its side.
Next I grouped the 2 objects and bound the groups width to the signal generator value. (This makes the bow tie grow from right to left only).
To get the center out effect, I bound the X position to an expression (x - (signal Gen / 2). This worked but the value of X being a constant made the object only work in that one spot.
In order to be able to move the object anywhere I want, I create a custom property called ‘BeginX’ and used it in the expression. (BeginX - (signal gen / 2))
Now when I want to position the object On my screen, I just enter the left most position value in the BeginX property and the expression moves the object right or left. To move it up or down I just use the original Y value.

Anyone have a better idea?


Actually, there’s nothing wrong with it, if it gives you the effect you want.

Here’s an example using multiple png files.

EDIT: Hey! The forum won’t let me post the zip file. Here’s a link to my Dropbox entry:

Using the Image Management tool, put the png files into a folder named, aptly enough, ‘mixer’.

For those interested, I used SimLab Composer (Animation Edition) and Snagit, two of my favorite tools.

The mixer is from a SolidWorks model imported into SimLab. The neat thing about SimLab is that I can use it to render an animation, but it can also render to individual frames. Unfortunately, jpg was my best choice. :unamused:

Snagit’s batch converter let me convert all the files to pngs. If I wished, I could also set color depth and resize the images.

Sorry, let me back up a moment. The reason I generally go with png files is that they are (generally) a bit more compact and they also have a channel available for transparency. :thumb_right:

Finally, the tedious part was to ‘erase’ the background from each image. Still, from starting to look for the model to finished window took approximately 30 minutes.