Trait pbrt::core::light::Light

pub trait Light {
    fn sample_li(
        &self, 
        iref: &InteractionCommon, 
        u: &Point2f, 
        wi: &mut Vector3f, 
        pdf: &mut Float, 
        vis: &mut VisibilityTester
    ) -> Spectrum;
    fn power(&self) -> Spectrum;
    fn preprocess(&self, scene: &Scene);
    fn le(&self, _ray: &mut Ray) -> Spectrum;
    fn pdf_li(&self, iref: &dyn Interaction, wi: Vector3f) -> Float;
    fn sample_le(
        &self, 
        u1: &Point2f, 
        u2: &Point2f, 
        time: Float, 
        ray: &mut Ray, 
        n_light: &mut Normal3f, 
        pdf_pos: &mut Float, 
        pdf_dir: &mut Float
    ) -> Spectrum;
    fn pdf_le(
        &self, 
        ray: &Ray, 
        n_light: &Normal3f, 
        pdf_pos: &mut Float, 
        pdf_dir: &mut Float
    );
    fn get_flags(&self) -> u8;
    fn get_n_samples(&self) -> i32;
}

Required Methods

fn sample_li(
    &self,
    iref: &InteractionCommon,
    u: &Point2f,
    wi: &mut Vector3f,
    pdf: &mut Float,
    vis: &mut VisibilityTester
) -> Spectrum

Returns the radiance arriving at a point at a certain time due to the light, assuming there are no occluding objects between them.

fn power(&self) -> Spectrum

fn preprocess(&self, scene: &Scene)

fn le(&self, _ray: &mut Ray) -> Spectrum

fn pdf_li(&self, iref: &dyn Interaction, wi: Vector3f) -> Float

fn sample_le(
    &self,
    u1: &Point2f,
    u2: &Point2f,
    time: Float,
    ray: &mut Ray,
    n_light: &mut Normal3f,
    pdf_pos: &mut Float,
    pdf_dir: &mut Float
) -> Spectrum

fn pdf_le(
    &self,
    ray: &Ray,
    n_light: &Normal3f,
    pdf_pos: &mut Float,
    pdf_dir: &mut Float
)

fn get_flags(&self) -> u8

fn get_n_samples(&self) -> i32

Implementors

impl Light for DiffuseAreaLight

fn sample_li(     &self,     iref: &InteractionCommon,     u: &Point2f,     wi: &mut Vector3f,     pdf: &mut Float,     vis: &mut VisibilityTester ) -> Spectrum

fn power(&self) -> Spectrum

fn preprocess(&self, _scene: &Scene)

fn le(&self, _ray: &mut Ray) -> Spectrum

fn pdf_li(&self, iref: &dyn Interaction, wi: Vector3f) -> Float

fn sample_le(     &self,     u1: &Point2f,     u2: &Point2f,     _time: Float,     ray: &mut Ray,     n_light: &mut Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float ) -> Spectrum

fn pdf_le(     &self,     ray: &Ray,     n: &Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float )

fn get_flags(&self) -> u8

fn get_n_samples(&self) -> i32

impl Light for DistantLight

fn sample_li(     &self,     iref: &InteractionCommon,     _u: &Point2f,     wi: &mut Vector3f,     pdf: &mut Float,     vis: &mut VisibilityTester ) -> Spectrum

fn power(&self) -> Spectrum

fn preprocess(&self, scene: &Scene)

Some of the DistanceLight methods need to know the bounds of the scene. Because lights are created before the scene geometry, these bounds aren't available when the DistanceLight constructor runs. Therefore, DistanceLight implements the optional preprocess() method to get the bound. This method is called at the end of the Scene constructor.

fn le(&self, _ray: &mut Ray) -> Spectrum

Default implementation returns no emitted radiance for a ray that escapes the scene bounds.

fn pdf_li(&self, _iref: &dyn Interaction, _wi: Vector3f) -> Float

fn sample_le(     &self,     u1: &Point2f,     _u2: &Point2f,     time: Float,     ray: &mut Ray,     n_light: &mut Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float ) -> Spectrum

fn pdf_le(     &self,     _ray: &Ray,     _n_light: &Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float )

fn get_flags(&self) -> u8

fn get_n_samples(&self) -> i32

impl Light for InfiniteAreaLight

fn sample_li(     &self,     iref: &InteractionCommon,     u: &Point2f,     wi: &mut Vector3f,     pdf: &mut Float,     vis: &mut VisibilityTester ) -> Spectrum

fn power(&self) -> Spectrum

Like directional lights, the total power from the infinite area light is related to the surface area of the scene. Like many other lights the power computed here is approximate.

fn preprocess(&self, scene: &Scene)

Like DistanceLights, InfiniteAreaLights also need the scene bounds; here again, the preprocess() method finds the scene bounds after all of the scene geometry has been created.

fn le(&self, ray: &mut Ray) -> Spectrum

Because infinte area lights need to be able to contribute radiance to rays that don't hit any geometry in the scene, we'll add a method to the base Light class that returns emitted radiance due to that light along a ray that escapes the scene bounds. It's the responsibility of the integrators to call this method for these rays.

fn pdf_li(&self, _iref: &dyn Interaction, w: Vector3f) -> Float

fn sample_le(     &self,     u1: &Point2f,     u2: &Point2f,     time: Float,     ray: &mut Ray,     n_light: &mut Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float ) -> Spectrum

fn pdf_le(     &self,     ray: &Ray,     _n_light: &Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float )

fn get_flags(&self) -> u8

fn get_n_samples(&self) -> i32

impl Light for PointLight

fn sample_li(     &self,     iref: &InteractionCommon,     _u: &Point2f,     wi: &mut Vector3f,     pdf: &mut Float,     vis: &mut VisibilityTester ) -> Spectrum

fn power(&self) -> Spectrum

fn preprocess(&self, _scene: &Scene)

fn le(&self, _ray: &mut Ray) -> Spectrum

Default implementation returns no emitted radiance for a ray that escapes the scene bounds.

fn pdf_li(&self, _iref: &dyn Interaction, _wi: Vector3f) -> Float

fn sample_le(     &self,     u1: &Point2f,     _u2: &Point2f,     time: Float,     ray: &mut Ray,     n_light: &mut Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float ) -> Spectrum

fn get_flags(&self) -> u8

fn get_n_samples(&self) -> i32

fn pdf_le(     &self,     _ray: &Ray,     _n_light: &Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float )

impl Light for SpotLight

fn sample_li(     &self,     iref: &InteractionCommon,     _u: &Point2f,     wi: &mut Vector3f,     pdf: &mut Float,     vis: &mut VisibilityTester ) -> Spectrum

fn power(&self) -> Spectrum

fn preprocess(&self, _scene: &Scene)

fn le(&self, _ray: &mut Ray) -> Spectrum

Default implementation returns no emitted radiance for a ray that escapes the scene bounds.

fn pdf_li(&self, _iref: &dyn Interaction, _wi: Vector3f) -> Float

fn sample_le(     &self,     u1: &Point2f,     _u2: &Point2f,     time: Float,     ray: &mut Ray,     n_light: &mut Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float ) -> Spectrum

fn get_flags(&self) -> u8

fn get_n_samples(&self) -> i32

fn pdf_le(     &self,     ray: &Ray,     _n_light: &Normal3f,     pdf_pos: &mut Float,     pdf_dir: &mut Float )