ambroisie/pathtracer
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library: render: utils: use Unit for vectors

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This commit is contained in:
Bruno BELANYI 2020-04-06 15:23:41 +02:00
parent c1801a7a78
commit ddebd55fcd
1 changed files with 4 additions and 5 deletions
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9
pathtracer/src/render/utils.rs
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@ -72,8 +72,7 @@ impl RefractionInfo {
/// Returns a random ray in the hemisphere described by a normal unit-vector, and the probability
/// to have picked that direction.
#[allow(unused)] // FIXME: remove once used
pub fn sample_hemisphere(normal: Vector) -> (Vector, f32) {
pub fn sample_hemisphere(normal: Unit<Vector>) -> (Unit<Vector>, f32) {
let mut rng = thread_rng();
let azimuth = rng.gen::<f32>() * std::f32::consts::PI * 2.;
// Cosine weighted importance sampling
@ -94,11 +93,11 @@ pub fn sample_hemisphere(normal: Vector) -> (Vector, f32) {
let normal_b = normal.cross(&normal_t);
// Perform the matrix calculation by hand...
let scattered = Vector::new(
let scattered = Unit::new_normalize(Vector::new(
x * normal_b.x + y * normal.x + z * normal_t.x,
x * normal_b.y + y * normal.y + z * normal_t.y,
x * normal_b.z + y * normal.z + z * normal_t.z,
);
));
// The probability to have picked the ray is inversely proportional to cosine of the angle with
// the normal
@ -133,7 +132,7 @@ mod test {
// NOTE(Bruno): should use some test-case generation for failure-reproduction purposes...
let mut rng = thread_rng();
for _ in 0..100 {
let normal = Vector::new(rng.gen(), rng.gen(), rng.gen());
let normal = Unit::new_normalize(Vector::new(rng.gen(), rng.gen(), rng.gen()));
for _ in 0..100 {
let (sample, proportion) = sample_hemisphere(normal);
let cos_angle = normal.dot(&sample);