__author__ = 'thoth'

#
# This is just a hack to visualize point density distribution of two
# different methods of picking random points on a sphere.
#
# random_sphere_1 is evenly distributed, while random_sphere_2 has
# higher point density at the poles.
#

import bpy
from math import *
from random import *

def random_sphere_1(r, n):
    mesh = bpy.data.meshes.new("uniform")
    verts = []

    for i in range(n):
        theta = asin(random()*2-1)
        phi = random()*2*pi

        z = sin(theta)*r
        q = cos(theta)*r
        x = q*cos(phi)
        y = q*sin(phi)
        verts.append( [x,y,z] )

    mesh.from_pydata(verts, [], [])
    return mesh


def random_sphere_2(r, n):
    mesh = bpy.data.meshes.new("polar")
    verts = []

    for i in range(n):
        theta = random()*2*pi
        phi = random()*2*pi

        z = sin(theta)*r
        q = cos(theta)*r
        x = q*cos(phi)
        y = q*sin(phi)
        verts.append( [x,y,z] )

    mesh.from_pydata(verts, [], [])
    return mesh

#

scn = bpy.context.scene
r = 2
n=5000
s1 = bpy.data.objects.new("uniform", random_sphere_1(r, n))
s1.location = [-4,0,0]
scn.objects.link(s1)
s2 = bpy.data.objects.new("polar", random_sphere_2(r, n))
s2.location = [4,0,0]
scn.objects.link(s2)