Curve profile is going to save me lots of time...

Have you come up with a good Moho trick? Need help solving an animation problem? Come on in.

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ponysmasher
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Curve profile is going to save me lots of time...

Post by ponysmasher »

At first glance the curve profile tool seemed kind of nice but not that interesting, but after seeing Selgin's curly hair example I started looking at it some more and now I love it.

I tried doing three tedious things that I've done before.

First, cog wheels. Creating them by hand can take some work, now:
Image
Bam, a perfectly spinnable cogwheel!

Next, vegetation. I hate doing trees and bushes in AS.
I've tried doing them in photoshop with brushes, but then I have to use images and I prefer to keep as much as possible in vectorformat.

I've tried making one tree and then duplicating and making some variations with the magnet tool but the results are not ideal.

Now:
Image
Changing the shape is easy now that there are so few points and you can easily make variations.

And last, one of the most tedious things to make in AS, chains:
Image
If you can't decipher it from the picture, I had to use two lines with mirror imaged curve profiles to make these chains.

The result is not a perfect chain but good enough in many situations and it's very easy to animate it.

One downside I've noticed is that the more curvature a point has, the more stretched out the profile becomes:

Image

That might be usable in some situations, but not very good for rigid stuff like chains (unless you want it to look like its in perspective I guess).

Anyway, I just wanted to share some of the possibilities of the curve profile tool.
sbtamu
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Post by sbtamu »

Yes, I like the new feature a lot. Also you can use it to animate something like a flower blooming or just about anything.
Sorry for bad animation

http://www.youtube.com/user/sbtamu
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heyvern
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Post by heyvern »

A cool trick for a chain like that to avoid the "stretching"... double up on the curve profile. Instead of ONE link have two.

Also a chain is not going to be "flexible". If you create a bone for each point and bind to bones for animation you can avoid large changes in length of the spline and avoid some of the stretching. With the double link profile shape it hides it even more.

-------------

A shame that curve profiles don't react to physics. I built a TON of gears in AS for use with physics. Not fun. I was working on a script to create gear ratios.... uh... maybe if I worked for NASA I could figure out the freaking math involved. ;)


-vern
ponysmasher
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Post by ponysmasher »

I used this technique to get a perfectly symmetrical cog wheel:

Turn on grid and create a shape like this:
Image

Select the two cogs, copy them and rotate while holding SHIFT
Image

Repeat until you have a cog wheel:
Image

You get more than one shape but it would work with physics.
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heyvern
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Post by heyvern »

That's exactly how I did it as well to draw my cogs.

The "tricky" part I discovered was how cog wheels actually work with each other. The physics are very accurate in AS, you can't just have any old cog wheels work well together unless the tolerences are very forgiving. There is a whole mathematical formula for calculating teeth ratios and angles of the inner sides etc etc. Imagine clock makers. If it was easy anyone could do it. ;) lots of very complicated math.

I built a clock in AS based on some plans I found on the internet and was able to trace the cog wheels. All my previous attempts failed in AS because the teeth would bind up. It was nearly impossible to create more than one or two wheels that worked in unison without binding up.

I found some cog wheel calculation formulas online. I was hoping to use them to create a lua script to draw proper cog ratios so they work well together.

-vern
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Rai López
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Post by Rai López »

heyvern wrote: I found some cog wheel calculation formulas online. I was hoping to use them to create a lua script to draw proper cog ratios so they work well together.
Uy, that sounds lovely! Of course the first thing I treat to made combining Curve Profiles & Physics was a little gear system with the commented (no) results :( ...Then I tried to construct the gears manually (there's no comparison :x) and I experimented too that heyvern said about bind ups, hmmm... more complications than I expected at first so I decided to passed to another things...

Ah, and I remember a curve effect for Inkscape that do exactly that you want to do, so I wonder if being an open source program (although I know usually this things are not so simple) won't be possible to look into it with reference purposes...
...
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