Struct arendur::bxdf::microfacet::Beckmann

pub struct Beckmann {
    pub ax: Float,
    pub ay: Float,
}

A Beckmann microfacet distribution

With microfacet distribution specified as $D(\omega_h) = \frac{ \exp{-tan^{2\theta_h(cos2\phi_h/\alpha_x2+sin2\phi_h/\alpha_y2)}} }{ \phi*\alpha_x*\alpha_y*cos^4\theta_h }$

Fields

ax: Float

microfacet oriented perpendicular to x-axis

ay: Float

microfacet oriented perpendicular to y-axis

Trait Implementations

impl Copy for Beckmann

impl Clone for Beckmann

fn clone(&self) -> Beckmann

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Beckmann

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl MicrofacetDistribution for Beckmann

fn distribution(&self, wh: Vector3f) -> Float

Given the macro surface normal wh, returns the differential area of microfacets from that angle

fn lambda(&self, w: Vector3f) -> Float

Given a direction w, return masked prjected surface area per visible projected surface area along that direction, assuming this value is independent from wh.

fn sample_wh(&self, wo: Vector3f, u: Point2f) -> Vector3f

given a uniform sample, return a sampled macro normal wh

fn visible(&self, w: Vector3f) -> Float

fraction of facets visible from w. The masking-shadowing function $G_l$ This interface assumes independence from wh

fn visible_both(&self, w0: Vector3f, w1: Vector3f) -> Float

fraction of facets visible from both w0 and w1

fn pdf(&self, wo: Vector3f, wh: Vector3f) -> Float

given wo and a sampled wh, returns the pdf of this sample