2 Splines with same settings are different

[h.zeihsel]

In the file i attached there are two Spline which have the same settings and control points (at least as far as i can tell) however they are clearly two different curves. 

The white spline is the behaviour i would expect from a NURBS curve. However the red spine differs from that.

I would be glad if someone could explaine the difference between the two.

[Alfred.NESWADBA · Accepted solution]

Hi,

DXF-Code 40 is different for these 2 splines.

Here a screenshot comparing the 2 splines:

This is the DXF documentation on SPLINE values, code 40 is listed as "knot value".

I don't know which value this exact is (I thought it's knot weight, but this would be 41), but at least this is the difference.

https://knowledge.autodesk.com/search-result/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD-DXF/files/GUI...

- alfred -

[ilia.borisov]

• @Alfred.NESWADBA if its not secret could you tell us which is the program to view that stats

[h.zeihsel]

I am not sure but i think he used something like notepad++ with a compare plugin to compare both splines as defined in .dxf. 

I kind of forgot that the knot values also change the NURBS spline since i didnt really find how to display them in autocad. Maybe someone knows where and how to change that?  I can change the weights but not the knot vector in the properties.

[Alfred.NESWADBA]

Hi,

>> if its not secret could you tell us which is the program to view that stats

I simply used Notepad++ (you can use any ASCII-editor) to look into the DXF-code.

- alfred -