View Full Version : Basic question about blandshapes and straight lines.

02 February 2004, 10:53 AM
Hi "folks".

A question about blend shapes and curves/straight lines. Maybe a little stupid..

When setting up character deformation I often refrain from using blendShapes, due to the fact that they interpolate in straight lines, which much in life obviously does not. I'll use clusters or other techniques to get curved paths of movement instead.

But I often see people recommend setting up e.g. eyelid deformation with shapes, using one or more in-betweens. The problem for me is that it, by default anyway, still creates straight lines - just more of them. And to me that does often not look very good in animation.

I know that you could achieve curved movement by driving several shapes via set-driven, but it seems to me there should be a way to get smooth interpolation paths between shapes just by setting up a target and an in-between shape. Maybe with a script or plug-in, that let's you adjust curves in the graph editor or some thing like that.

Anybody know how it's done or what script does the trick (if any)??

Thank’s a lot!

:) Nenox

Matt Leishman
02 February 2004, 05:01 PM
well, i know that when you actually go about setting keys on the blendshape attribute itself, you will have available to you the linear f-curve in the graph editor. You can then go into the graph editor and add all the curviness you'd like to that curve. the problem is that you won't be editing the interpolation of the shapes, but instead you'll be editing the ease in ease out of the shift from one shape to another.

hope that makes some sense in regards to the available f-curves for blendshapes.

(I always use clusters for eyelids)

02 February 2004, 12:12 AM
Hi Sith. Thank you for your answer!

Yes that makes perfect sense. If you have your default tangent type set to linear anyway. :)

My mentioning f-curves was just a way to indicate a level of control that would be nice. It could be parametrically controlled or with a viewport manipulator or bounding box etc.

Before starting the thread I was quite in doubt whether the straight lines were in fact a premise of the morphing technology. I'm now pretty confident that it is.

Still, if anybody knows of a neat plug, script or trick I would appreciate it a lot! Otherwise I'll just have to set-up my own "Combination Sculpting for Very Dummy's" to get those curvy shape interpolations. (Read: set driven key)

...Ohh wait! Isn't combination sculpting when you use a third shape to compensate for two or more other shapes messing each other up.. or not?!? See? I need HELP!! :)


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