I'd look at using something like Gearotic for this. Or at least ask on the Gearotic forum if you want to roll your own.

- Peer

https://www.gearotic.com/Home.html

@Michael Gibson sorry for confusing explanation.

My ArrayRoll differs from Circular Array by putting this equation into the Radial Step field:

- RollDiameter * PI * (AngleToFill / 360) / (ItemCount - 1)

where user has to enter only the circle diameter on which the arrayed item will roll. Here's a visual example ot normal array, vs roll array:

Normal array:

Roll circular array:


The roll shifts the rack perpendicularly to the curve normal at given step by the arc-length of the step.

Now I want to do the same with Curve Array, to shift the arrayed object perpendicularly to the path curve normal (or in other words parallel to the path curve) at a each step of the array, by the length of the step-segment of the path curve.
For a circle it is a simple slicing of circumference value by step size to get the offset. If the Curve array distributes the elements at a constant-length segments of the path curve, the equation would be simple.


@Peer and @Pilou thanks for pointing out the Gearotic, didn't know about it, the price is kind of high doe.

Hi Fubax,

re:
> If the Curve array distributes the elements at a constant-length segments
> of the path curve, the equation would be simple.

Curve array does distribute objects at arc length stations along the path curve.

There are 2 modes for specifying the arc length distance, there is a "distance" mode where you give the distance directly, or there is "Item count" mode where you give an integer item count and the segment distance is calculated by NumSegments = NumItems-1 and SegLength = TotalCurveLength / NumSegs.

Stations are positioned along the curve with a coordinate frame at each one:





Objects are then translated and rotated from the first frame onto each station's frame:



There isn't a specific parameter for giving a distance along the curve normal but if you translate the input objects in the direction of the normal at the start of the curve it should have that effect:



- Michael

Thanks Michael for the response.

I would like to progressively shift the objects, parallel to the curve at each station.

If such parallel shift would amount to the step arc length, the object would essentially just roll over the curve, as if having a flat base.

*Edit
Essentially I'm looking for a "Radial Step" functionality from Circular Array in the Curve Array. Does this addition require changes to the factory, or can it be done in java script?

Hi Fubax, sorry no there isn't any progressive stepping built in to the array curve factory.

But it seems like it shouldn't be too difficult for a script to generate it.

If you have an object to array along the curve like this:



Your script could generate copies along the curve normal at the first position:



And then do a CurveArray of all those and harvest the desired piece at each station and discard the rest:



Or another method is the script could create a line along the curve normal at the base position and include it in the objects to array, then it could examine the line created at each station and use it as the direction to move that station's objects.

Let me know if neither of these methods will do what you need.

- Michael

I think the "double" array method would do the job. Would that be doable with NodeEditor Plus, the selection of a specific element of the first, linear array at each station? Maybe the Nodeeditor could even further automate the process and generate envelope path from the final array result?

HI Fubax,

re:
> Would that be doable with NodeEditor Plus, the selection of a specific element of the
> first, linear array at each station?

I'm not sure, I'm not familiar enough with the Node editor myself. I can set up an example .js script though, do you want that?

- Michael