Plugin for Hash Animation:Master V9.0 or higher.
Smoothes out surfaces with creases. This only includes creases produced by the way A:M calculates tangents.
This plugin is freeware. Please mail (mbricman@kci-group.com) me a link to your work if you use it !
Zettle is available for PC and MAC.

Animation:Master has quite an easy way of calculating tangents through a Control Point (CP):



The "reference" line of a CP is the virtual line though the previous and the next CP. A:M makes the tangent in a CP parallel to its reference line.
This is a very quick and simple calculation. (the end tangent take more effort, because there is no previous (or next) CP)
Also your modeling usually benefits from this locality of tangent finding, because local changes in your model remain local (bezier spline interpolation usually takes all points into the calculation).

The method described has a disadvantage though: in some situations it is a bit "too local":



(the red, blue and green lines show the tangents and their origin) At point B the spline looks very "strained".



We would expect the spline to settle in this point just as the yellow line & tangent show, but due to the used calculation, this is not possible.
In a model this will result in creasing that will show at render time.

There are generally 3 approaches to get what we want:

refining geometry
At this one - line example it would be fairly easy to add a point between B and C and and one between C and D at certain positions, to get this effect, but in other situations this might not be the way to go, because your mesh gets more dense (sometimes even more creases are introduced by refining).

juggling CPs
It is possible to move the CPs to certain positions, so they dont produce creases. This method is very time-consuming and often altering your geometry and therefore possibly limiting your artistic freedom.

tweaking gammas
Gamma value tweak the tangent angle. a value of 10 means, that always 10° are added to the tangent angle.

Zettle is making the process of tweaking gammas easier. It automatically calculates the correct gamma in the selected points and applies it.

Gamma tweaking has a big disadvantage in animation though: gamma can "pop" your spline in the different direction than you meant, if certain changes are made to the spline.
To demontrate this, i have moved the point C a bit to the right.



You have to know that gamma values are always applied "away from" the reference line. in our picture a gamma of -45 means, that the tangent is rotated by 45 degrees "toward" the reference line (thin blue line).
Now lets nudge C a bit to the left:



The gamma is still applied "towards" the reference line as stated above, but the reference line is on the other side now!

Since soft body animation ALWAYS moves CPs, it is quite likely, that some CPs will cross that border. So always look carefully which gammas you tweak!

Zettle is compensating the described problem (only) in the modeling process. If you have zettled a CP and move it across the border, just zettle it again and the gamma will be ok again.

Since Zettle is using a very specific approach to tweaking the gamma, it might be possible, that it produces quite stupid corrections in certain situations. If you find such situations, please mail a detailed description of the situation, possibly i can modify the algorithm to adapt to your findings.

Select the CPs you want to zettle, right - click on them, select "Plugins", then "Wizards", then "Zettle...".

I have to pan (basically modify) the view just a bit to get the update visible. This is with EVERY HXT plugin, so its unlikely to be a bug in Zettle. Probably you have the same problem (i usually just click on the mouse-wheel and drag a bit after applying the plugin).

Its a good idea to ONLY select the CPs you want to be tweaked, because unnecessary gammas (and MOST CPs do get tweaked if zettled) are never good for animation.

I have noticed, that Zettle does not work correctly, it some normals of your model are facing the wrong direction. always check the normals direction when modeling ([SHIFT]-[1] shows the normals) and correct them (select patch and "Flip Normals").

Zettle was applied to all CPs in this model. Especially the round forehead area (that wont change during animation anyway, and therefore is safe to tweak) has become substantially smoother.
Though i'd not generally advise you to apply Zettle to all of your model, you could just look what parts benefit from Zettling and then load the unZettled version again and zettle only the areas where it helps.

1.0 Initial release
1.1 Fixed hook handling (cps with hooks are not zettled anymore)

Download zettle.zip for PC
Download zettle.hqx for MAC

Close A:M.
Unzip, copy the Zettle.hxt to your A:M HXT plugin folder (like C:\Program Files\Hash Inc\V90\hxt)
Run A:M.

Use this plugin at your own risk, i did not have any kind of problem while using it, but its always a good idea to save often. especially before using a plugin.