Export bezier curves

Question

I placed some bezier curves in a scene. This scene is getting exported as an .obj file later with a scaling factor of 11 and +X-axis as Forward and +Z-Axis as Up. as In a further project some insects shall move along these curves. Now I need the handle and control points of these bezier curves in world coordinates so I can use these coordinates to calculate the bezier curves in my project. I wrote a script for that:

import bpy
import os

ob = bpy.context.object
currPath = os.path.splitext(bpy.data.filepath)[0]+".txt"
file = open(currPath, "w")

for curves in bpy.data.curves:
    for splines in curves.splines:
        for x in range(len(splines.bezier_points)): 
            file.write("p ")
            handle_left = ob.matrix_world * splines.bezier_points[x].handle_left
            handle_left *= 11
            co = ob.matrix_world * splines.bezier_points[x].co
            co *= 11
            handle_right = ob.matrix_world * splines.bezier_points[x].handle_right
            handle_right *= 11
            file.write("%.3f " % (handle_left.x))
            file.write("%.3f " % (handle_left.y))
            file.write("%.3f " % (handle_left.z)) 
            file.write("%.3f " % (co.x)) 
            file.write("%.3f " % (co.y)) 
            file.write("%.3f " % (co.z))
            file.write("%.3f " % (handle_right.x))
            file.write("%.3f " % (handle_right.y)) 
            file.write("%.3f " % (handle_right.z))
            file.write("\n")
    file.write("n\n")

file.close()

The bezier curves are not at the position where they should be in my project. Is something wrong with the script?

Answer 1

Now I have found a way to export the bezier curves in world coordinates. To do so I name all my bezier curves "BezierCurve01", "BezierCurve02",...,"BezierCurve18" and so on. I also have to make sure that the curves are in exactly this order in the table bpy.data.curves. This is achieved by simply renaming every curve. Then I can run the following script to get the desired output:

import bpy
import os

currPath = os.path.splitext(bpy.data.filepath)[0]+".txt"
file = open(currPath, "w") 
i = 1

for curves in bpy.data.curves:
    idx = str(i)
    if i < 10:
      bezier = "BezierCurve0"+idx
    else:
      bezier = "BezierCurve"+idx
    ob = bpy.data.objects.get(bezier, None)
    for splines in curves.splines:
        for x in range(len(splines.bezier_points)): 
            file.write("p ")
            handle_left = ob.matrix_world * splines.bezier_points[x].handle_left
            handle_left *= 11
            co = ob.matrix_world * splines.bezier_points[x].co
            co *= 11
            handle_right = ob.matrix_world * splines.bezier_points[x].handle_right
            handle_right *= 11
            file.write("%.3f " % (handle_left.y))
            file.write("%.3f " % (-handle_left.x))
            file.write("%.3f " % (handle_left.z)) 
            file.write("%.3f " % (co.y)) 
            file.write("%.3f " % (-co.x)) 
            file.write("%.3f " % (co.z))
            file.write("%.3f " % (handle_right.y))
            file.write("%.3f " % (-handle_right.x)) 
            file.write("%.3f " % (handle_right.z))
            file.write("\n")
    file.write("n\n")
    i = i + 1

file.close()

This only works for 20 curves and has to be adjusted properly for more.

Answer 2

thanks for your work so i decide to post my work here....

now it will exports all bezier_points in all curve(the data will be used in a three.js project

import bpy
import os


currPath = os.path.splitext(bpy.data.filepath)[0]+ ".curves.js"
file = open(currPath, "w") 

file.write('var curves = {\n')
for ob in bpy.data.objects.values() : 
  if ob.type == 'CURVE' :
    file.write( '"%s":\n' % ob.name)
    for spline in ob.data.splines :
      if len(spline.bezier_points) > 0 :
        file.write("[")
        for bezier_point in spline.bezier_points.values() : 
          handle_left  = ob.matrix_world * bezier_point.handle_left
          co           = ob.matrix_world * bezier_point.co
          handle_right = ob.matrix_world * bezier_point.handle_right

          file.write("[[%.3f, %.3f, %.3f],  " % (handle_left.x, handle_left.y, handle_left.z ))
          file.write("[%.3f, %.3f, %.3f],  " % (co.x, co.y, co.z ))
          file.write("[%.3f, %.3f, %.3f]],\n  " % (handle_right.x, handle_right.y, handle_right.z ))

    file.write("],\n")
file.write("}\n")
file.close()