Objects
The following classes are available in the atom_access package.
Sphere– A sphere object with a radius and a center point.
Ray– Contains all information required to define a ray of light and its intersection with a sphere.
The intersection of a given ray with a given sphere can be calculated using the Ray.intersect method.
Rays can be generated using the Ray.from_zcw class method, which returns a list of rays evenly distributed
on the surface of a sphere according to the ZCW algorithm.
This submodule contains ray and sphere objects and methods used for raytracing
- class atom_access.objects.Ray(theta: float, phi: float)
Contains all information required to define a ray of light and its
intersection with an object. A ray is defined by its polar and azimuthal
angles, is assumed to have unit length, and passes through the origin.
- Parameters:
theta (float) – Polar angle 0 <= theta <= pi
phi (float) – Azimuthal angle 0 <= phi <= 2pi
- theta
Polar angle 0 <= theta <= pi
- Type:
float
- phi
Azimuthal angle 0 <= phi <= 2pi
- Type:
float
- r
Length of ray, assumed unity (ray is normalised)
- Type:
float
- x
x component of ray vector in cartesian coordinates
- Type:
float
- y
y component of ray vector in cartesian coordinates
- Type:
float
- z
z component of ray vector in cartesian coordinates
- Type:
float
- cart
Direction vector of ray as (3,) np.array
- Type:
np.ndarray[float]
- intersection
True if ray intersects with object
- Type:
bool
- r_i
Distance of closest intersection point from origin.
If no intersection, then this is set to np.inf.
- Type:
float
- cart_i
Position vector of closest intersection point as (3,) np.array
- Type:
np.ndarray[float]
- blocked_by
List of atom labels the ray intersects with, with the closest
listed first
- Type:
list(str)
- calc_cart_i() None
Calculates position vector of intersection point using intersection
distance
- Parameters:
None
- Return type:
None
- classmethod from_zcw(density: int) list[Ray]
Generate a set of rays emanating from a single point using the ZCW
algorithm
See Appendix I in
Edén, M.; Levitt, M. H. J. Magn. Res., 1998, 132, 220-239.
- Parameters:
density (int) – Density number for ZCW algorithm
- Returns:
List of ray objects
- Return type:
list[Ray]
- property intersection: bool
True if ray intersects with object, else False
- class atom_access.objects.Sphere(radius: float, center: ndarray[tuple[int, ...], dtype[_ScalarType_co]], name: str)
Contains all information required to define a sphere and to calculate
its intersection with a ray
- Parameters:
radius (float) – Radius of sphere
center (np.ndarray[float]) – x,y,z coordinates of sphere center
name (str) – Name of sphere (e.g Atom label with indexing number)
- radius
Radius of sphere
- Type:
float
- radius2
Squared radius of sphere
- Type:
float
- center
x,y,z coordinates of sphere center
- Type:
np.ndarray[float]
- center_dist
Distance to center from origin
- Type:
np.ndarray[float]
- name
Name of sphere (e.g Atom label with indexing number)
- Type:
str
- intersect(ray: Ray) tuple[bool, float, float]
Calculate intersection points of normalised ray vector with
sphere if they exist.
- Parameters:
ray (Ray) – Ray object
- Returns:
bool – True if intersection, else False
float – First intersection point, 0 if no intersection
float – Second intersection point, 0 if no intersection