tfg.math.spherical_harmonics.evaluate_spherical_harmonics

Evaluates a point sample of a Spherical Harmonic basis function.

This function is implementating the algorithm and variable names described p. 12 of 'Spherical Harmonic Lighting: The Gritty Details.

In the following, A1 to An are optional batch dimensions.

degree_l An integer tensor of shape [A1, ..., An, C], where the last dimension represents the band of the spherical harmonics. Note that degree_l must be non-negative.
order_m An integer tensor of shape [A1, ..., An, C], where the last dimension represents the index of the spherical harmonics in the band degree_l. Note that order_m must satisfy 0 <= order_m <= l.
theta A tensor of shape [A1, ..., An, 1]. This variable stores the polar angle of the sameple. Values of theta must be in [0, pi].
phi A tensor of shape [A1, ..., An, 1]. This variable stores the azimuthal angle of the sameple. Values of phi must be in [0, 2pi].
name A name for this op. Defaults to "spherical_harmonics_evaluate_spherical_harmonics".

A tensor of shape [A1, ..., An, C] containing the evaluation of each basis of the spherical harmonics.

ValueError if the shape of theta or phi is not supported.
InvalidArgumentError if at least an element of l, m, theta or phi is outside the expected range.