I am a new Blender user and couldn't find the API for adding a quarter-cylinder object. And I also want to build the object like the picture shows. Thanks if you can help!
2 Answers
I'm not sure exactly what shape you want to make.
This will create an annular sector of a cylinder.
import bpy
import math
def create_cylinder_sector(
height,
angle_start,
angle_end,
inner_radius,
outer_radius,
inner_segments,
outer_segments,
):
angle_diff = angle_end - angle_start
inner_angle_step = angle_diff / inner_segments
outer_angle_step = angle_diff / outer_segments
verts, faces = [], []
# Verts: Inner arc
if inner_radius > 0:
for i in range(inner_segments + 1):
angle = angle_start + inner_angle_step * i
x = inner_radius * math.cos(angle)
y = inner_radius * math.sin(angle)
verts.append((x, y, 0))
verts.append((x, y, height))
else:
verts.append((0, 0, 0))
verts.append((0, 0, height))
# Verts: Outer arc
for i in range(outer_segments + 1):
angle = angle_end - outer_angle_step * i
x = outer_radius * math.cos(angle)
y = outer_radius * math.sin(angle)
verts.append((x, y, 0))
verts.append((x, y, height))
# Faces: Three sides
for i in range(0, len(verts), 2):
faces.append((i, i+1, i+3, i+2))
# Faces: Fourth side
faces.append((len(verts) - 2, len(verts) - 1, 1, 0))
# Faces: Bottom
faces.append([i for i in range(0, len(verts), 2)])
# Faces: Top
faces.append([i for i in range(len(verts) - 1, 0, -2)])
mesh = bpy.data.meshes.new("CylinderSector")
mesh.from_pydata(verts, [], faces)
mesh.validate()
ob = bpy.data.objects.new(mesh.name, mesh)
bpy.context.scene.collection.objects.link(ob)
return ob
# Example
create_cylinder_sector(
height=1,
angle_start=0.4,
angle_end=1.8,
inner_radius=0.5,
outer_radius=1.5,
inner_segments=3,
outer_segments=6,
)
If you want a quarter like this, you can pass inner_radius=0
:
create_cylinder_sector(
height=1,
angle_start=0,
angle_end=math.pi/2,
inner_radius=0,
outer_radius=1.5,
inner_segments=3, # ignored when inner_radius=0
outer_segments=9,
)
To build a quarter cylinder using a Python script, you can follow these steps:
- Import the required modules:
import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.mplot3d import Axes3D
- Define the radius of the cylinder:
r = 1
- Define the height of the cylinder:
h = 1
- Define the number of points to be used for the plot:
n = 100
- Generate the x, y, and z coordinates for the plot using numpy:
theta = np.linspace(0, np.pi/2, n)
x = r * np.cos(theta)
y = r * np.sin(theta)
z = np.linspace(0, h, n)
- Create a 3D plot using the generated coordinates:
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
ax.plot(x, y, z)
plt.show()
This will generate a quarter-cylinder plot with the specified radius and height. You can adjust the values of r, h, and n to change the dimensions and resolution of the plot.