Grow radius to animate a curve

Hi, there are many ways of animating vines or strokes -seen a couple of questions these days- and here’s yet another one :wink:

Since rotobezier is around I’ve been thinking in animating the radius to fade a curve ‘visibility’, this script does that by keyframing each point, it works with bezier and nurbs -beziers seems to work better- and you can even feed it with a mesh or a text and it will do the conversion.

You should setup start frame and length, plus a fade time if you want the curve to disappear.
It is advisable to subdivide the curve if you want to give extra detail to the animation.
Options like bevel depth and resolution can be adjusted later.

the updated script:
a little video:

have fun…

Wow, yet another magic script from Liero. Thank you! :stuck_out_tongue:

That is very nice.

Instant animation, gotta love it:yes:

Here’s previous video only that in vimeo… just threw a torus knot on scene -what a cool addon- and then ran this little script… Try the same with different settings. Remeber you can even run it on a mesh or a text. Subdivision are important here.

Here’s a quick test applied to Suzanne (I applied one subdivision before running Grow Radius). The script is incredibly easy to use:

Nice, it almost happens too fast.

@benu that was fun -maybe not so for the monkey-
here is an updated version of the script, I tried to make it even simpler to use, but it will work better on a 37260 build at least… please give it a try and tell me what you think!

get new version from the first post
the old one here

Thanks for the script(s) liero; very easy to use.

I made your standard animated bulging tube (with a few tweaks to the f curves):

Here’s the blend file:

lovely stuff, thanks!

thanks Gimble and steeve… nice to see you had fun with this

Wow this is awesome.

I am about to try it, but how do I apply the curve to another object, like Suzanne then grow it?

just select the mesh and click on button, it will do the conversion for you… maybe go edit mode and press the V key > automatic to change handles type…

but try it on you own curves, the point density there is a key factor to get nice results

Yes I find that you must be aware of the vertex density (to high and Blender chokes) and I couldnt use a 2d curve with faces.

you can’t have fills and radius -or a bevel object- in the same curve in blender… use two objects
and try curve simplify addon to reduce point count, too dense curves are bad :wink:


I am trying to use the grow radius script. No matter the object I choose(curve, polygon, subdivided or not) when I hit Keyframe Curve I get the following error:

Traceback (most recent call last):
File "C:\Program Files\Blender\2.59\scripts\addons_extern\", line 81, in execute
AttributeError: 'Curve' object has no attribute 'use_fill_front'
location:<unknown location>:-1
location:<unknown location>:-1

I use Blender 2.59.4, r40851M, built by bat3a from Graphicall. I am on a Windows 7 64 bit machine. Pyhon version is 3.2.2.


hi, comment out line 81 & the script works again.

I saw the changes to curves some days ago but didn’t think of updating scripts, thanks for reminding…! this should be fixed now. And remember to subdivide the curve if needed.
Thanks Meta-Androcto, checking other curve scripts now… done, I think I’ve fixed and uploaded them all

Meta-Androcto, thank you for reply. I tried your trick but it only works on a limited tipe of curves. For example it does not work on polygons.
Liero, I just downloaded the updated versions of the scripts and works like a charm. Thank you very much for sharing with us all that works and efforts to do marvelous things.


hi Liero,
I’ve added some tools & reorganized the menu & some renaming :wink:
The script I made from yours is called ‘Handwriting’

Link to script is here:

Thanks Liero for what I consider are some of the best scripts for blender.