Control width parameter in Nurbs Curve

[ITdreamer]

Hi

I've created a Nurbs Curve, connected Carve Sop to it, and animated the U parameter to create the illusion of growing. After that I created width attribute with AttributeCreate SOP. Rendered, and got a good looking stripe. The question is, how can I control the width parameter according to the U parameter of the point on the curve? I need to create a stripe, which is thin at the start and at the end of the curve, but thick in the middle of the curve. I need that to create a growing grass or leafs. Here is the illustration:

Thanks a lot

Width_Test.hip

Edited August 31, 2008 by ITdreamer

[MENOZ]

hi!

this is a method that i like, but it's only one of many method you can use do control the width attribute.

for shure there are more intuitive way to control this.

you give the "shape" to the curve using the curve in the channel editor, and you can animate the global width using the width parameter. you found the controls in the blue colored node.

really hope this helps!

Width_Test_menoz.hipnc

[ITdreamer]

Thanks a lot, good idea.

[MENOZ]

Thanks a lot, good idea.

maybe you could use the lenght of the curve to modify the width, so when the lenght is zero width is zero too, and as the lenght grows, the width grows too..

how can i find the lenght of the curve? i cannot remember how this colud be done..

[GallenWolf]

how can i find the lenght of the curve?

Measure sop?

GW

[Jason]

Measure sop?

...and/or the arclen() expression might be good for you too.

http://www.sidefx.com/docs/houdini9.5/expressions/arclen

[MENOZ]

thanks a lot!