From e90c8f135feb7b0272d3690b0e138488219c9d84 Mon Sep 17 00:00:00 2001
From: Yoel <s73017@beuth-hochschule.de>
Date: Fri, 20 Nov 2020 21:41:12 +0100
Subject: [PATCH] CirclePlane is now one sided and has correct emissionCalc and
sample function
---
RayTracer/shape/CirclePlane.cpp | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/RayTracer/shape/CirclePlane.cpp b/RayTracer/shape/CirclePlane.cpp
index f2bacf2..8d82ad1 100644
--- a/RayTracer/shape/CirclePlane.cpp
+++ b/RayTracer/shape/CirclePlane.cpp
@@ -18,7 +18,7 @@ std::optional<cam::Hit> CirclePlane::intersect(const cam::Ray& r) const {
float a = util::dot(d, n);
if (a == 0) {
return std::nullopt;
- } else {
+ } else if (a < 0) {
float t = -x0[1] / d[1];
util::Vec3 t_hitpoint = r(t);
@@ -27,26 +27,33 @@ std::optional<cam::Hit> CirclePlane::intersect(const cam::Ray& r) const {
} else {
return std::nullopt;
}
+ } else {
+ return std::nullopt;
}
}
util::AxisAlignedBoundingBox CirclePlane::bounds() const {
return util::AxisAlignedBoundingBox(util::Vec3(-radius, 0, -radius),
util::Vec3(radius, 0, radius));
}
-// THIS IS COPIED AND BAD TODO!!!!
util::SurfacePoint CirclePlane::sampleLight() const {
- float u[2] = {(float)util::dis0to1(util::gen),
- (float)util::dis0to1(util::gen)};
- float r = std::sqrt(u[0]) * radius;
- float theta = 2 * M_PI * u[1];
+ // Radius of the sampled point
+ float r = std::sqrt(util::dis0to1(util::gen)) * radius;
+ // Degreee of the sampled point
+ float theta = 2 * M_PI * util::dis0to1(util::gen);
+ // Polar coordinates have to be converted to cartesian
return util::SurfacePoint(
util::Vec3(r * std::cos(theta), 0, r * std::sin(theta)),
- util::Vec3(0, -1, 0), material);
+ util::Vec3(0, 1, 0), material);
+ // The sampled point will be in local coordinates.
}
util::Vec3 CirclePlane::calculateLightEmission(const util::SurfacePoint& p,
const util::Vec3& d) const {
- // Diffus ist hier im dot-product eingebettet
- return p.albedo() * (p.emission() * util::dot(p.normal(), d.normalize())) /
- std::pow(d.length(), 2);
+ // Basically this is just the emission at a surface point. And the pdf dimms
+ // the light in regard to the angle
+ auto emission = p.emission();
+ auto dot = std::max<float>(util::dot(p.normal(), d.normalize()), 0);
+ auto area = M_PI * std::pow(radius, 2);
+ auto pdf = std::pow(d.length(), 2) / (dot * area);
+ return emission / pdf;
}
} // namespace shapes
--
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