ArrayCrv not consistently spacing objects

I’m distributing point along a rectangle curve using the ArrayCrv command. The curve is perfectly flat and on the cPlane. When I distribute the points along the curve, the distance between then is different from what U specify in the command window. This happens regardless which “transform” option I select "e.g., freeform, road, etc.). And then sometimes it’ll work fine, consistently spacing points around the rectangle at the specified distance. Any idea what’s going on?

Here is a 3dm file illustrating the problem.
arrayCrv problem.3dm (48.3 KB)

This first image shows the command setup.

This second image shows the result. The grid circles are 17.5’ apart on the X and Y axes so the arrayed point should be equidistant from the grid circles around the curve as I specified a distance of 17.5’. For some reason, however, the distance between the distributed curves is around 18.6’.

This final image shows the outcome when the ArrayCrv command does what I expect, spacing the objects at a consistent 17.5’ from one another. As far as I can tell, there is no rhyme or reason as to why it works as expected sometimes and other times spaces the objects at a different distance than the one specified.

I guess you would need to post a file that illustrates the problem… If you are distributing points along a curve with an even distance, the Divide command might help.

Images uploaded to original post. Hope they help!

Hello - please just post a 3dm file with the inputs and incorrect output.


Done. Please see the original post.

Hello - there are 19 little squares, and 18 circles, around that perimeter… I guess that would do it…If I ArrayCrv at 18 and set the bae point to the center of the initial square it seems to work out as expected.

Blue is my arrayed object.


This is very odd. I’ve done as you suggest and specified the number of objects to array rather than their spacing, and for some reason it works. But when I specify the distance, it doesn’t. This, in spite of the fact that the number and distance values are the same regardless of which I specify (i.e., if I specify 18 object, the distance value updates to 17.5’; and if I specify the distance to be 17.5’, the count value updates to 18). There simply seems to be an issue with specifying the distance. Is this a bug?

Hello - yes, I see - this appears to be a bug - the count is 17 even though it says 18 when specifying the distance. Thanks for pointing this out.
I think the reason is this - if you specify distance it seems not to want to wrap the array around the seam point on the curve.
RH-64062 ArrayCrv: cannot wrap the array on the curve seam


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RH-64062 is fixed in the latest Rhino 7 Service Release Candidate