Problem with NurbsCurve Component

Hi guys,

I encountered a strange problem with the "NurbsCurve" component. The one where you can set individual weights. However:

I can't work with the curve generated by the "NurbsCurve" command. The "Network Surface" doesnt give me any error but it simply doesnt do anything.

The strange thing is that if I bake the generated curve and use the referenced one (turquoise group) everything is fine. The points should be also fine because when I generated the curves via "Interpolate" it also works fine...

Example.3dm

Example.gh

Do you have any ideas why? I also tried to rebuild the "NurbsCurve" generated one. Divide into points and redo the curve with another command, etc. ... nothing

Many thanks! Julian

Replies to This Discussion

Permalink Reply by David Rutten on July 23, 2017 at 4:32am

The problem is not with the Nurbscurve, it is made just fine. The problem is the Network Surface component. It failed to create a surface given the inputs.

The reason for this is that the order of the V curves is incorrect (unlike the NetworkSrf command, the component does not try to reorder the inputs). The order we'd expect is { 'Referenced planar curve', 'Planar curve', 'Referenced planar curve' }, but instead, we get this:

The reason the order is wrong is because the D1, D2 and D3 inputs of the Merge component have different tree topologies, by which I mean the paths under which the data are stored have different lengths:

Your referenced curves are stored under {0}, whereas your nurbscurve is stored under {0;0}. If you merge this data and only then flatten it, you end up with the wrong order. If you flatten the inputs to the Merge component (or, modify the nurbscurve path to be similar to the other ones), then the merge will generate the correct order.

Permalink Reply by Julian Jauk on July 23, 2017 at 11:23am

Hi David!

thanks for your fast and detailed explanation. My mistake (of course), I spent quite a lot of time checking all the components around but not the "merge"... I thought by flattening it at the end it would be all fine but now I understand why it's not

Works just fine, again thank your very much

Julian

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