Use attribute to control parameter? Change thickness of sweep afterwards with attribute?

[Krion]

Hi!

 

I have a little experience with attributes and VEX now.  I've used the color of some object to transfer color to an other object or to change pscale of other points.

But now i've come across a difficult problem, and i was wondering if there is some mysterious new thing in Houdini i don't yet yet that could help me with this.

I have animated 4 boxes and i have connected these boxes with a dashed line. The thickness of the lines is controlled by a circle which is the input of 6 sweeps. Since i want to separate the controls for the 2 middle lines (in the grey red boxes) and the 4 outside lines (in the grey network boxes), i've created two transform nodes.

While i was on the result below, i realised i wanted the thickness of the lines to be controlled by a gradient, like i've done before with color and pscale (attributetransfer), instead of with keyframing.

(this screenshot has copied timeshifts)

But this is a hard problem because the thickness is controlled so early in the network. 

So i wonder if there is a way i could do this? If there exists some way i could control the thickness of the line after the sweep with the gradient/color attribute i've created in the node called 'gradient'?

AttributeToParameter__.hipnc          (mentioned nodes colored red)

 

Would really appreciate your help.  

 

Edited March 23, 2019 by that Abstract guy

[Sophie]

Do you mean you want to set the width of the geometry that you have of the line, over the length of that whole line? Because then you can create a width attribute for just that line that is controlled by a ramp.

[Krion]

On 3/20/2019 at 3:59 PM, that Abstract guy said:

 

[Krion]

(Sorry there was a bug in Odforce there: couldn't edit or type in that comment, had to sent) 

Anyways..  

I mean something like this:

So not only over that whole line, but really from an outside source.

But i didn't know about the width attribute yet.. How would you do that? 

 

 

 

Edited March 23, 2019 by that Abstract guy

[davpe]

it depends how exactly you have your network wired but this is how I would do it:
 

float baseWidth = detail('../../path_to_external_node', 'existingWidthAttribute', 0);

float widthRamp = @ptnum/@numpt;

@width = baseWidth * widthRamp;

this will read a value from an external node (it doesn't necessarily have to be a detail attrib) and multiplies it with locally generated ramp. the resulting @width I'd use as a source for polywire SOP, or sweep SOP

Edited March 25, 2019 by davpe