the periodic property of the spline curve maybe wrong

[jqw2009]

Describe the bug
When I save the drawing as a 2018 version DWG, the "is periodic" property of the spline curve should be true, but it is read as false.

In AutoCAD, I found the issue when creating the spline curve using the fit point method; the control point method works fine

Release needed

• Yes, using the Nuget package.

[DomCR]

Hi @jqw2009,

The flag IsPeriodic seems to be locked in Autocad when the Spline is closed and is generated using FitPoints, I guess that is mandatory, you can also check the flags to see the generation method, SplineFlags1.MethodFitPoints.

I don't think the value is wrong, is just implicit for a closed spline generated using fitpoints.

Not sure what would be the best action here, changing the flags may cause unexpected errors on Autocad or other softwares.

[jqw2009]

@DomCR
I want to use this periodic property to determine whether to apply smooth processing at the start and end points. When the fit points are manually set so that the head and tail coincide, the closed property is true, but the periodic property is false. In this case, smooth processing should not be applied. Only when the closed property is manually set to true will smooth processing be triggered, and the periodic property will become true. To summarize: when the closed property is true, the periodic property can be either true or false, so we need to know its exact state.