PyQtGraph和OpenGL：如何在两个坐标之间创建球体？

Question

是否可以使用PyQtGraph和OpenGL在两个坐标之间创建一个球体？在我的示例代码中，我制作了一个球体，但是位置和大小仅由“行”和“列”决定。我想将球的端点连接在point1和point2之间。你能帮我吗？

from pyqtgraph.Qt import QtCore, QtGui
import pyqtgraph as pg
import pyqtgraph.opengl as gl
import numpy as np
import sys

app = QtGui.QApplication([])
w = gl.GLViewWidget()
w.show()
w.setCameraPosition(distance=15, azimuth=-90)

g = gl.GLGridItem()
g.scale(2, 2, 1)
w.addItem(g)

# coordinates
point1 = np.array([0, 0, 0])
point2 = np.array([0, 5, 0])

md = gl.MeshData.sphere(rows=10, cols=20)

m1 = gl.GLMeshItem(meshdata=md, smooth=True, color=(1, 0, 0, 0.2), shader='balloon', glOptions='additive')
m1.scale(1, 1, 2)
w.addItem(m1)


if __name__ == '__main__':

    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()

Answer 1

sphere（）方法返回与某个半径的球相关的数据（默认情况下为1），并且以（0，0，0）为中心，因此使用point1和point2的信息可以获得半径和中心，要建立中心，必须使用translate（）方法移动项目：

from pyqtgraph.Qt import QtCore, QtGui
import pyqtgraph as pg
import pyqtgraph.opengl as gl
import numpy as np
import sys

app = QtGui.QApplication([])
w = gl.GLViewWidget()
w.show()
w.setCameraPosition(distance=15, azimuth=-90)

g = gl.GLGridItem()
w.addItem(g)

# coordinates
point1 = np.array([0, 0, 0])
point2 = np.array([0, 5, 0])

center = (point1 + point2) / 2
radius = np.linalg.norm(point2 - point1) / 2

md = gl.MeshData.sphere(rows=10, cols=20, radius=radius)

m1 = gl.GLMeshItem(
    meshdata=md,
    smooth=True,
    color=(1, 0, 0, 0.2),
    shader="balloon",
    glOptions="additive",
)
m1.translate(*center)

w.addItem(m1)



if __name__ == "__main__":

    if (sys.flags.interactive != 1) or not hasattr(QtCore, "PYQT_VERSION"):
        QtGui.QApplication.instance().exec_()