To draw points one needs to prepare data in the array of coordinates [number_of_points, 3]. Colors for all the points can either be the same or have an individual value (colors attribute).
When the number of points is larger than $10^3$ it is recommended to use fast shaders: flat, 3d or 3dSpecular. The mesh shader generates much bigger overhead, but it has a properly triangularized sphere representing each point.
In [1]:
import k3d
import numpy as np
x = np.random.randn(1000,3).astype(np.float32)
point_size = 0.2
plot = k3d.plot(name='points')
plt_points = k3d.points(positions=x, point_size=0.2)
plot += plt_points
plt_points.shader='3d'
plot.display()
We can color points with some scalar value:
In [2]:
f = (np.sum(x**3-.1*x**2,axis=1))
colormap = k3d.colormaps.basic_color_maps.WarmCool
colors = k3d.helpers.map_colors(f,colormap,[-2,.1])
colors = colors.astype(np.uint32)
Using ipywidgets communication we can sent precomputed colors to the exising plot:
In [3]:
plt_points.colors = colors
In [4]:
plt_points.positions = {str(t):x/(1+t*3) for t in np.linspace(0,4,4)}
In [5]:
plot.start_auto_play()