def ConfigStar(mass=1.0):
"""
Determines the radius (in solar radii), temperature (in K), and
hexcolor of a star of given mass, assuming it is a main sequence star.
Parameters
----------
mass : float
Mass of star in solar masses (default 1.0)
Returns
-------
radius : float
radius of star in units of solar radius.
temp : float
temperature of star in Kelvin
hexcolor: string
hexcolor corresponding to stellar temperature.
"""
# Determine approximate radius in solar radii for both stars.
radius = Rad_calc(mass)
# Determines the approximate temperature of each star.
temp = Temp_calc(mass)
# Use scalar temperature to estimate hexcolor appropriate to each star
hexcolor = tc.rgb2hex(tc.temp2rgb(temp))[0]
return (radius, temp, hexcolor)
def OldStarMesh(temp=Te_Sun, rad=1, scale=(1, 1, 1), pos=[0, 0, 0]):
"""
This function creates a pythreejs object that represents a star using
a texture based on public domain STEREO Heliographic map made with
images taken of the Sun on Dec. 30, 2011. Image downloaded from
https://stereo.gsfc.nasa.gov/360blog/
and had its brightness and resolution rescaled.
Parameters
----------
temp : float
temperature of star in Kelvin (default 5777)
rad : float
radius of the star in system units (default 1)
scale : tuple
pythreejs scale in each dimension as tuple (default (1, 1, 1) )
pos : list
three-dimensional position as list (default [0, 0, 0] )
Returns
-------
star : pythreejs.Mesh
a spherical pythreejs Mesh object representing a star
"""
# Check is position is a list
if isinstance(pos, list):
# Check if this is a list of 3 items
if (len(pos) != 3):
raise TypeError('pos passed to StarMesh must be list of 3 numbers')
# Check that all the items in the list are numbers
for this_pos in pos:
try:
i = float(this_pos)
except ValueError:
raise TypeError('ValueError: pos contains list item that is not a number.')
else:
raise TypeError('pos passed to StarMesh must be list of 3 numbers')
# Check is scale is a tuple
if isinstance(scale, tuple):
if (len(scale) != 3):
raise TypeError('scale passed to StarMesh must be tuple of 3 numbers')
else:
raise TypeError('scale must be a tuple')
# Define color and texture of star surface
hexcolor = tc.rgb2hex(tc.temp2rgb(float(temp)))[0]
StarTexture = p3j.ImageTexture(imageUri='images/sun_surface.jpg')
# Create sphere using MeshBasicMaterial (which is unaffected by lighting)
StarSurface = p3j.MeshBasicMaterial(color=hexcolor, map=StarTexture)
StarGeom = p3j.SphereBufferGeometry(radius=rad, widthSegments=32,
heightSegments=16)
return p3j.Mesh(geometry=StarGeom, material=StarSurface,
position=pos, scale=scale)
def StarMesh(temp=Te_Sun, rad=1, scale=(1, 1, 1), pos=[0, 0, 0]):
"""
This function creates a pythreejs object that represents a star using
a set of nested spheres that are partly transparent to simulate limb
darkening.
Parameters
----------
temp : float
temperature of star in Kelvin (default 5777)
rad : float
radius of the star in system units (default 1)
scale : tuple
pythreejs scale in each dimension as tuple (default (1, 1, 1) )
pos : list
three-dimensional position as list (default [0, 0, 0] )
Returns
-------
star : pythreejs.Mesh
a spherical pythreejs Mesh object representing a star
"""
# Check is position is a list
if isinstance(pos, list):
# Check if this is a list of 3 items
if (len(pos) != 3):
raise TypeError('pos passed to StarMesh must be list of 3 numbers')
# Check that all the items in the list are numbers
for this_pos in pos:
try:
i = float(this_pos)
except ValueError:
raise TypeError(
'ValueError: pos contains list item that is not a number.')
else:
raise TypeError('pos passed to StarMesh must be list of 3 numbers')
# Check is scale is a tuple
if isinstance(scale, tuple):
if (len(scale) != 3):
raise TypeError(
'scale passed to StarMesh must be tuple of 3 numbers')
else:
raise TypeError('scale must be a tuple')
# Define color of star surface
hexcolor = tc.rgb2hex(tc.temp2rgb(float(temp)))[0]
# Number of transparent layers to use to build star
layers = 20
# Radial scaling
drad = 0.97
# Starting resolution
N_azi, N_pol = 32, 16
# Layer opacity
tau = 0.4
# Radii to use
radii = rad * drad**np.array(range(layers - 1, -1, -1))
# 3D object to represent star
star = p3j.Object3D()
# Build the object from inside out
for i in range(layers):
# Tweak number of vertices in sphere up for the outer surface sphere
if (i > (layers - 2)):
N_azi *= 2
N_pol *= 2
geom = p3j.SphereBufferGeometry(radius=radii[i],
widthSegments=N_azi,
heightSegments=N_pol,
renderOrder=-i)
material = p3j.MeshBasicMaterial(color=hexcolor,
transparent=True,
opacity=tau)
star.add(p3j.Mesh(geom, material))
# Set the position and scale of this mesh
star.position = pos
star.scale = scale
return star