Creating a Circle (spline) with varying number of points.
pim last edited by
If I create a circle, it has always just 4 points.
How can I create a circle (spline) with for example, 5 or 28 points?
eZioPan last edited by eZioPan
As far as I know, there is no way to make a "perfect circle" with any type of spline in
I search on the Internet, based on this answer: How to create circle with Bézier curves?.
I write the following code to create a circular-like spline shape:
import c4d, math #Welcome to the world of Python deg = math.pi/180.0 def main(): pCnt = 4 # Here is the point count radius = 200 # Here is the radius of circle subdAngle = 5*deg # Here is the subdivision angle #Prepare the data tangentLength = (4/3)*math.tan(math.pi/(2*pCnt))*radius # single side tangent handle length pointPosLs =  tangentLs =  for i in range(0,pCnt): angle = i*(2*math.pi)/pCnt # caculate the angle # caculate point position y = math.sin(angle)*radius x = math.cos(angle)*radius pointPosLs.append(c4d.Vector(x, y, 0)) # tangent position lx = math.sin(angle)*tangentLength ly = -math.cos(angle)*tangentLength rx = -lx ry = -ly vl = c4d.Vector(lx, ly, 0) vr = c4d.Vector(rx, ry, 0) tangentLs.append([vl, vr]) # init a bezier circle circle = c4d.SplineObject(pcnt=pCnt, type=c4d.SPLINETYPE_BEZIER) circle.ResizeObject(pcnt=pCnt, scnt=1) circle.SetSegment(id=0, cnt=pCnt, closed=True) circle[c4d.SPLINEOBJECT_CLOSED] = True circle[c4d.SPLINEOBJECT_ANGLE] = subdAngle circle.SetAllPoints(pointPosLs) # set point position # set tangent position for i in range(0, pCnt): circle.SetTangent(i, tangentLs[i], tangentLs[i]) circle.Message(c4d.MSG_UPDATE) return circle
You can try put this code in a
Python Generatorobject to get the result.
I'm not very sure about my answer, waiting for more convincing answers.
mp5gosu last edited by
You may also want to take a look at the official Cinema 4D SDK for an example of a circle object: https://github.com/PluginCafe/cinema4d_cpp_sdk_extended/blob/master/plugins/cinema4dsdk/source/object/circle.cpp
Though it's C++, the algorithm should be easily adaptable.
s_bach last edited by
Hello @pim ,
I guess you are talking about the "Circle" spline primitive? The generated spline has always 4 control points; there is no way to change that.
But you could try to get the generated spline and apply the "Subdivide" tool. Whit that tool you can add additional points.
pim last edited by
Thank you all, great answers!
I will take a different approach.
I convert the circle to a spline and then divide that spline into the wanted number of points.