vispy: two data sets on same plot with colors

Question

I have two 3d numpy arrays, and am trying to plot them in two distinct colors via a vispy 3d scatter.

I am already familiar with how you set data via scatter on vispy:

scatter.set_data(data)

where data is in the form of a numpy array. However, I need to plot two different data sets with two distinct colors, and I feel like there is something very obvious I am missing here. I'm fine with treating the two point sets as one data set, but then how do you get two distinct colors for the point groups?

Answer 1

I modified the scatter example from the vispy repo to do what you are asking.

Result:

Code:

# pylint: disable=no-member
""" scatter using MarkersVisual """

import numpy as np
import sys

from vispy import app, visuals, scene


# build your visuals, that's all
Scatter3D = scene.visuals.create_visual_node(visuals.MarkersVisual)

# The real-things : plot using scene
# build canvas
canvas = scene.SceneCanvas(keys='interactive', show=True)

# Add a ViewBox to let the user zoom/rotate
view = canvas.central_widget.add_view()
view.camera = 'turntable'
view.camera.fov = 45
view.camera.distance = 500

# data
n = 500
# generate 2 point clouds
cloud1 = np.random.rand(n, 3) * 100
cloud2 = np.random.rand(n, 3) * 100
# cloud1 -> orange
# cloud2 -> white
color1 = np.array([[1, 0.4, 0]] * n)
color2 = np.ones((n, 3))

# stack point clouds and colors
pos = np.vstack((cloud1, cloud2))
colors = np.vstack((color1, color2))


# plot ! note the parent parameter
p1 = Scatter3D(parent=view.scene)
p1.set_gl_state('translucent', blend=True, depth_test=True)
p1.set_data(pos, face_color=colors, symbol='o', size=10,
            edge_width=0.5, edge_color='blue')

# run
if __name__ == '__main__':
    if sys.flags.interactive != 1:
        app.run()