Make a sprite spin AND move in a direction

Keith Price

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Dec 13, 2013, 8:42:30 PM12/13/13

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I'm New to App Inventor, but experienced VB programer...

As far as I can tell, you SPIN an object (such as a wheel) by continually updating its heading. Is that accurate?

But, then you MOVE an object by setting it's speed and interval. And, it moves in the direction of its heading. I'm I wrong?

If that's the case, then how would you spin an image AND make it move in a direction w/o creating a spiral effect? Simplest example would be a wheel spinning and moving across the screen.

TIA

Hal Abelson

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Dec 13, 2013, 9:05:59 PM12/13/13

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You're absolutely connect. You couldn't just say "move" here. You'd have to also update the position on clock ticks, by changing the x,y coordinates. App Inventor is not designed for the kind of compound objects you want. Maybe someday ...

Keith Price

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Dec 13, 2013, 9:09:44 PM12/13/13

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Ahh. OK. Thanks for setting me straight on that.

Scott Ferguson

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Dec 13, 2013, 9:31:31 PM12/13/13

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This cycloid demo rotates an ImageSprite 'wheel' as it moves across a Canvas. The movement in the X direction is synchronized with the wheel rotation.

I will work on an example done with AI2 that demonstrates a simple rolling wheel.

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Scott

Scott Ferguson

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Dec 14, 2013, 10:34:20 AM12/14/13

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I just simplified the project in AI Classic. Converting to AI2 would be easy.

It is much simpler without the cycloid feature - basically a one-line formula.

More here: https://groups.google.com/forum/#!category-topic/mitappinventortest/connect-with-programmers/5zO-MNp-DPs

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hAPPy INVENTORing!

Scott

M. Hossein Amerkashi

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Dec 14, 2013, 10:36:33 AM12/14/13

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Nice job Scott.

-Hossein.

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Keith Price

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Dec 14, 2013, 1:50:58 PM12/14/13

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Hey, that's GREAT! Thanks so much. All of you.

On Friday, December 13, 2013 5:42:30 PM UTC-8, Keith Price wrote:

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