Cannot retrieve world coordinates of NURBS curve vertices.

chrissie · April 30, 2018, 5:53am

I try to get the world coordinate of Vertex 0 of a selected Nurbs curve:

obj = bpy.context.selected_objects[0]
wmtx = obj.matrix_world
localCoord = obj.data.splines[0].points[0].co
worldCoord = wmtx * localCoord
print([B]"localCoord: " + str(localCoord))
print("worldCoord: " + str(worldCoord))

The attached screenshots show I do NOT receive the correct coordinates.
(switching between global/local coordinate view in the panel).

I attach the Blender file and screenshots. Its just a basic Nurbs curve, nothing special…

Whats wrong please???

[/B]

Attachments

chrissie · April 30, 2018, 5:53am

Here is the .blend file with the spline.

Attachments

problem nurbs world coordinates.blend (467 KB)

chrissie · April 25, 2018, 11:47pm

Ok, 1 thing I found out now:

The samples either show how to retrieve vertex world coords from Meshes or from Bezier Curves, like here:

gist.github.com

https://gist.github.com/satishgoda/5160102

bpy_curve_object_local_world_coordinates.py

# Create a bezier curve object

>>> bpy.ops.curve.primitive_bezier_curve_add()
{'FINISHED'}

# Get a reference to the curve object

>>> curve_object = bpy.context.active_object

# Print out its data path

This file has been truncated. show original

But it does not work for Nurbs curves (why?).

A workaround is to convert the Nurbs to a Bezier, and proceed from there.