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[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Just Animate - Wheels![/FONT][FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] [/FONT][FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular](for Maya)[/FONT][FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]
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- [FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]How do you make wheels turn automatically? [/FONT]
- [FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]What are expressions in Maya? [/FONT]
- [FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]So who is Pythagoras anyway?[/FONT]
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As for Pythagoras, well... we don't quite answer that directly... but we do have:[/FONT]
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Over 55 minutes of free training (575Mb of uncompressed pure video tutorial!) covering everything from basic math principles to application of those principles to a real problem.[/FONT]
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Please note this material is copyrighted © 2003, Lost Pencil Animation Studios Inc. Feel free to copy it, send it to your best friend, but please do not sell it or pass it off as your own.[/FONT]
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Section 1: Introduction[/FONT]
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Well... the introduction... you know, preamble about what we will do, an example of moving the cart around and showing how the wheels turn automatically no matter what direction you turn the cart (err... chariot).[/FONT]
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>> View Clip >>[/FONT]
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Section 2: What's a 'Circumferance'?[/FONT]
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Ok, I don't mean to insult anyone's intelligence, but I'm thinking that at one point or another we have all been in the 'I-don't-know-what-circumferance-has-to-do-with-rolling-a-wheel" boat. I want to make sure that everyone can follow this tutorial to the sweet end.[/FONT]
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On that note, this section talks about what circumferance is and it's relationship to how far a wheel rolls. Don't worry, the clip starts with a blank white screen before the educator (that would be me) starts scribbling.[/FONT]
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>> View Clip >>[/FONT]
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Section 3: Creating a formula...[/FONT]
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So now that we know the relationship between the circumferance of the wheel and it's rotation on the ground, let us make a shmancy formula to define that relationship so we can use it in Maya.[/FONT]
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Don't let the scribble stop you, this is foundational stuff for when we get into Maya and create our expression to roll our wheel. If you do this step by step, it should all make sense![/FONT]
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>> View Clip >>[/FONT]
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Section 4: Creating a formula... part 2[/FONT]
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Just when you thought the math was over... we need to refine our formula so that it includes things we know and then we can use it for that one thing... the thing we don't know... confused yet?[/FONT]
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>> View Clip >>[/FONT]
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Section 5: Creating a formula... part 3[/FONT]
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One more thing we can do to the formula to simplify it...[/FONT]
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>> View Clip >>[/FONT]
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Section 6: Creating a formula... part 4[/FONT]
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Now we have to figure out the distance the wheel moves, but how do we determine the distance between two points? Maya only knows about the position of the wheel in X and Z values (well, Y too, but it doesn't concern us here), so how do you calculate the distance between points?[/FONT]
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>> View Clip >>[/FONT]
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Section 7: Creating a formula... part 5[/FONT]
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Here is the formula for calculating the distance between two points... and here we mention that Pythagoras fella...[/FONT]
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>> View Clip >>[/FONT]
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Section 8: Creating a formula... part 6[/FONT]
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Here are the gory details of where the distance formula comes from... and we mention that Pythagoras fella again...[/FONT]
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(note: just realized there is a boo boo in the clip... when I write out the formula in red I have (z2-z1), but it too should be squared (just like x2-x1)).[/FONT]
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>> View Clip >>[/FONT]
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Section 9: Now to make the Expression...[/FONT]
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So now that we have the theory behind us, how does this translate to Maya's Mel Expression language? [/FONT]
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>> View Clip >>[/FONT]
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Section 10: Wheel heirarchy[/FONT]
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What controls do we need and how do we need to parent these controls in order to make all this work?[/FONT]
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>> View Clip >>[/FONT]
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Section 11: The Expression... part 1[/FONT]
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Here we walk, step by step, through the actual Maya Expression that is used to drive the wheel. This is where the 'rubber meets the road' ) We fall back on the things we've learned in the previous clips and implement them to make the wheel turn.[/FONT]
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>> View Clip >>[/FONT]
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Section 12: The Expression... part 2[/FONT]
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More details on how and why the expression does what it does... these parts are the meat of the tutorial.[/FONT]
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>> View Clip >>[/FONT]
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Section 13: The Expression... part 3[/FONT]
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Even more details on how and why the expression does what it does... after you've watched this you should know a bunch about expressions in Maya, how wheels turn, and maybe a little bit about Pythagoras (well, okay, not much about the fella, but maybe something about some of his thinking).[/FONT]
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>> View Clip >>[/FONT]
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Section 14: Attaching wheels to a Cart[/FONT]
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So now that we have this shmancy turning wheel, how do we use it? Here, in the conclusion, we build a two wheeled cart and attach the wheels so that they rotate properly... they even rotate properly when turning a corner (the inside wheel turns slower than the outside wheel). We attach the cart to a curve and make it go on it's own... [/FONT]
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Anyway, I hope you enjoyed this tutorial - oh, and if you could, please remember our bandwidth usage and associated cost issues... )[/FONT]
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>> View Clip >>[/FONT]
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The source files are found on the CD under wheel_source.zip.[/FONT]