[openglCylinder] A cylinder with arbitrary orientation for the opengl renderer. #manim #3D #cylinder #opengl

20250123_openglcylinder.py

# https://discord.com/channels/581738731934056449/1332024484496150589/1332024484496150589

from manim import *
from manim.opengl import *
config.renderer="opengl"
config.write_to_movie=True

class openglCylinder(OpenGLSurface):
    def __init__(self, start=ORIGIN, end=LEFT, radius=0.05, color=WHITE, **kwargs):
        start = np.array(start)
        end = np.array(end)
        direction = end-start
        theta = np.arctan2(direction[1],direction[0])
        phi   = np.arctan2(direction[2],np.linalg.norm(direction[0:2]))
        length = np.linalg.norm(direction)

        def uvfunc(u,v): # cylinder around x-axis
            return np.array([v, radius * np.cos(u), radius * np.sin(u)])
        super().__init__(
            uv_func=uvfunc,
            u_range=[0,2*PI],
            v_range=[0,length],
            fill_color=color,
            **kwargs
        )
        self.rotate(angle=phi, axis=DOWN, about_point=ORIGIN)
        self.rotate(angle=theta, axis=OUT, about_point=ORIGIN)
        self.shift(start)


class testcylinder(ThreeDScene):
    def construct(self):
        self.set_camera_orientation(phi=75 * DEGREES, theta=-60 * DEGREES)
        ax = ThreeDAxes().add_coordinates()
        self.add(ax)
        self.add(
            openglCylinder(start=ax.c2p(0,0,0),end=ax.c2p(3,3,3))
        )

readme.md