Hi,

i am trying to animate the outlines of a font. In general i am trying the following approach, which i found in an vimeo tutorial:

font node, e.g. letter B, into an divide node with ‘remove shared edges’ and ‘compute dual’ checked, into an foreach node

Within the foreach node, a resampe node, into a carve node

Now this animates, but a) it starts the animation whereever it thinks the outline starts, and b) it animates the outer curves clockwise and the inner curves counter clockwise.

I want more control over it as i want a) choose where exactly the animation starts on the closed curve, and b) animate all three edges (in case of the letter B) in the same direction.

My idea was, to use an ‘attribute create’ that sets an atrribute, e.g. ‘index’ with stamp(“..”, “FORIDXVALUE”, 0)

Then another attribute create, that sets an attribute, e.g. ‘iseven’ of @index%2

Then make two groups that create a groupeven and groupodd depending if iseven is 0 or 1

Then make two animated carve nodes, one for group groupeven and one for gropuodd that animate in different directions.

Now two problems here:

Problem 1: I don't see whats going on, as geometry spreadsheet in the for loop seems to only show values for loop index 0, so how can i make it show the values from the other curves?

Problem 2: Is this really the best way to do this in houdini? It seems quite complex for a simple task: animate clockwise

Any help appreciated, thanx

I noticed i actually mixed the new approach with an older approach…. I do not need odd/even, but simply two groups for @attri>0 and @attri<1, for animating the outer curve in one direction and all remaining curves in the opposite directions, but while making it simpler, it still does not work.

have you got the video link?

it would help me to understand your effect much better at the moment i would just guess for a solution. when you have a hip file that you can share (no project data required just a example that illustrate your problem) would help too.

The tutorial:

https://vimeo.com/41667113 [vimeo.com]

File attached, if you dive into the two foreach nodes, you'll see what i mean, i made one similar to the tutorial, and one how i (as a total houdini noob) would expect it to work.

Thank you for your help

OK, i found a solution that works.

still the question is: is there a better solution, especially for defining a starting point on the edge.

Currently the starting point is defined by the lowest point number per edge and you could move it by playing with the first u/v values of the animating carve, but it would be a pain.

don't know if this is ‘better’, but its definitely ‘a’ way.

-create an @offset attrib per curve prim
-promote that down to the points
-in a new style for/each loop:
–create a @u attrib along the curve
–offset @u by @offset
–sort the points by @u
–rebuild the curve to use this new point order
–keyframe the growth using your now cleanly parameterised curve

Thank you very much, awesome example. exactly what i was looking for.