The error you’re encountering, NameError: name 'curvature' is not defined, indicates that the variable curvature is being referenced before it has been assigned a value in the calculate_curvature function. This is because the calculate_curvature function in the provided code is just a placeholder and does not have a proper implementation for calculating the curvature.
To resolve this error, you need to implement the calculate_curvature function. Curvature calculation can be complex and depends on how you define curvature for a spline. A basic approach is to calculate the angle between vectors formed by consecutive points, but more advanced techniques might involve fitting curves or using differential geometry.
Here’s a simple way to calculate the angle between three points, which can serve as a rough measure of curvature:
def angle_between_points(p0, p1, p2):
Calculate the angle between three points. Points are c4d.Vector objects.
angle = math.acos(dot_product / (magA * magB))
def optimize_spline(spline, angle_threshold):
points = spline.GetAllPoints()
for i in range(1, len(points) - 1):
angle = angle_between_points(points[i - 1], points[i], points[i + 1])
if angle < angle_threshold:
points_to_remove.append(i)
# Remove points from spline
# This might involve creating a new spline or modifying the existing one
spline = doc.GetActiveObject()
if spline is None or not spline.CheckType(c4d.Ospline):
raise ValueError("No spline object selected")
angle_threshold = math.radians(5) # Example threshold in radians
optimize_spline(spline, angle_threshold)
This script calculates the angle at each point and compares it to a threshold. Points with an angle below this threshold are considered for removal. Note that this is still a basic example and might need refinement for practical use. For instance, removing points can change the shape of the spline, so you might want to implement additional checks or a more sophisticated curvature calculation.