View Full Version : thickness variation

08 August 2004, 12:09 PM
how can i make a thickness variation on a cylinder that is deformed by a curve?
i would like it to be thinner at the beginning, then thicker, then thinner in the middle again, and thicker to the end again. is there some kind of operator for this?

or do i need to use the lattice for that? - the problem is, i'm sketching the curve and then apply the cylinder deformed on this curve. it would be no problem to use lattice if the curve was straight, but it's very complex curvature and when i then deform a cylinder on it and apply lattice the lattice is being applied globally. and i need the thickness to variate at some local points of the curvature.

08 August 2004, 12:40 PM
better then a curve deformation, if you need simple things like a cylinder, is using an envelope.

-draw the curve and shape animate it from the desired shape to straight
-use a chain from curve with many bones and envelope the cylinder to it
-envelope the cylinder to the straight bones
-play the shape animation of the curve and bones and cylinder will follow

it's a bit tricky (but not as much as it sounds when reading it) but you gain weight controls. to shrink and deform partial areas of the cylinder you can scale and twist the bones, and you have several layers of operators for convincing animation and tweaking.

plus the deformation this way ends up in the animation stack, that means you can tweak the modelling shape of the cylinder at leisure and see it updating in a result window.

08 August 2004, 05:44 PM
Jaco's technique is particularily important if you don't want your object to be stretched by the curve, ie when 2 points on the curve are further apart than others. We had to do some 'energy tentacles' recently and this was how we approached it.

If stretching isn't as much of a factor, you can apply the curve deformation in the Animation Mode, letting you apply any local deformations (ie lattice) before the curve deformation occurs.

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