A minimal reproduction of arrows problem

mona_with_arrows.py

import numpy as np
import vispy.app
from vispy import gloo
from vispy import visuals,scene
from vispy.visuals.transforms import STTransform,NullTransform


def get_image():
    """Load an image from the demo-data repository if possible. Otherwise,
    just return a randomly generated image.
    """
    from vispy.io import load_data_file, read_png
    
    try:
        return read_png(load_data_file('mona_lisa/mona_lisa_sm.png'))
    except Exception as exc:
        # fall back to random image
        print("Error loading demo image data: %r" % exc)

    # generate random image
    image = np.random.normal(size=(100, 100, 3))
    image[20:80, 20:80] += 3.
    image[50] += 3.
    image[:, 50] += 3.
    image = ((image - image.min()) *
             (253. / (image.max() - image.min()))).astype(np.ubyte)
    
    return image


def build_arrows(zpos=-1,color='white'):
    x1 = np.random.randint(50,650,(200,2))
    x2 = x1 + np.random.randint(-20,20,(200,2))
    x3 = np.zeros((x1.shape[0]*2,2))
    x3[::2]=x1; x3[1::2]=x2;
    x3 = x3[:,[0,1,1]]; x3[:,2]=zpos

    arrows = scene.visuals.Arrow(
                pos=x3,
                color=color,
                connect='segments',
                arrows=x3.reshape((-1,6)),
                # method='gl',
                arrow_color=color,
                arrow_size=12,
                arrow_type='curved',
                antialias=True,
            )
    return arrows



canvas = scene.SceneCanvas(keys='interactive')
mona = get_image()
canvas.size = mona.shape[1],mona.shape[0]
canvas.show()

# Set up a viewbox to display the image with interactive pan/zoom
view = canvas.central_widget.add_view()
image = scene.visuals.Image(mona, interpolation='nearest', parent=view.scene, method='subdivide')

view.camera = scene.PanZoomCamera(aspect=1)
view.camera.flip = (0, 1, 0) ## otherwise she's upside down.
view.camera.set_range()

# s = 700. / max(image.size)
# t = 0.5 * (700. - (image.size[0] * s)) + 50
# image.transform = STTransform(scale=(s, s), translate=(t, 50))

arr1 = build_arrows(-100,'blue')
arr1.parent = image
arr2 = build_arrows(100,'white')
arr2.parent = image

vispy.app.run()