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From ca0480a8c55b38d9a5651c34b7b9b0defac22b3a Mon Sep 17 00:00:00 2001
From: Syndamia <kamen@syndamia.com>
Date: Tue, 4 Jun 2024 12:22:39 +0300
Subject: [PATCH] [hw12-hard] Implemented proper solid angle for rectangular
lights
---
flake.lock | 27 +++++++++++++++++++++++++++
flake.nix | 26 ++++++++++++++++++++++++++
src/lights.cpp | 32 +++++++++++++++++++-------------
src/lights.h | 2 ++
src/main.cpp | 2 +-
src/vector.h | 4 ++++
6 files changed, 79 insertions(+), 14 deletions(-)
create mode 100644 flake.lock
create mode 100644 flake.nix
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..25db693
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+ "nodes": {
+ "nixpkgs": {
+ "locked": {
+ "lastModified": 1716061101,
+ "narHash": "sha256-H0eCta7ahEgloGIwE/ihkyGstOGu+kQwAiHvwVoXaA0=",
+ "owner": "nixos",
+ "repo": "nixpkgs",
+ "rev": "e7cc61784ddf51c81487637b3031a6dd2d6673a2",
+ "type": "github"
+ },
+ "original": {
+ "owner": "nixos",
+ "ref": "nixos-23.11",
+ "repo": "nixpkgs",
+ "type": "github"
+ }
+ },
+ "root": {
+ "inputs": {
+ "nixpkgs": "nixpkgs"
+ }
+ }
+ },
+ "root": "root",
+ "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..d0a99fd
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,26 @@
+# Този файл, заедно с flake.lock са си за моета система, да имам копие ако случайно изтрия нещо
+{
+ description = "hexray raytracer in FMI elective";
+
+ inputs = {
+ nixpkgs.url = "github:nixos/nixpkgs/nixos-23.11";
+ };
+
+ outputs = inputs:
+ let
+ pkgs = inputs.nixpkgs.legacyPackages."x86_64-linux";
+ in {
+ devShells."x86_64-linux".default = pkgs.mkShell {
+ nativeBuildInputs = with pkgs; [
+ cmake
+ pkg-config
+ ];
+
+ buildInputs = with pkgs; [
+ SDL2
+ openexr_3
+ zlib
+ ];
+ };
+ };
+}
diff --git a/src/lights.cpp b/src/lights.cpp
index f6edef4..d5b0ed6 100644
--- a/src/lights.cpp
+++ b/src/lights.cpp
@@ -74,9 +74,8 @@ int RectLight::intersect(const Ray& ray, double& intersectionDist)
void RectLight::beginFrame()
{
- Vector pts[3];
- for (int i = 0; i < 3; i++) {
- pts[i].x = (i % 2) ? -0.5 : 0.5;
+ for (int i = 0; i < 4; i++) {
+ pts[i].x = (i % 3) ? -0.5 : 0.5;
pts[i].y = 0;
pts[i].z = (i < 2) ? -0.5 : 0.5;
pts[i] = T.transformPoint(pts[i]);
@@ -87,16 +86,23 @@ void RectLight::beginFrame()
scaleFactor = 1 / m_area;
}
+static Vector projectOnUnitSphere(const Vector& toProj, const Vector& sphereCenter) {
+ return sphereCenter + normalize(toProj - sphereCenter);
+}
+
double RectLight::getSolidAngle(const Vector& p)
{
- Vector lightDirCanonic(0, -1, 0);
- //
- Vector lightDirWorld = T.transformDir(lightDirCanonic);
- Vector lightPosWorld = T.transformPoint(Vector(0, 0, 0));
- Vector lightToP = p - lightPosWorld;
- double cosTerm = dot(lightToP, lightDirWorld);
- if (cosTerm < 0) return 0;
- double d = lightToP.length();
- cosTerm /= d;
- return m_area * cosTerm / sqr(1 + d);
+ Vector ppts[4];
+ for (int i = 0; i < 4; i++) {
+ ppts[i] = projectOnUnitSphere(this->pts[i], p);
+ }
+
+ double dihedrals = 0.0;
+ for (int i = 0; i < 4; i++) {
+ Vector n1 = (ppts[(i - 1 + 4) % 4] - p) ^ (ppts[i] - p);
+ Vector n2 = (ppts[(i + 1) % 4] - p) ^ (ppts[i] - p);
+ dihedrals += radBetween(n1, n2);
+ }
+
+ return dihedrals - 2.0 * M_PI;
}
diff --git a/src/lights.h b/src/lights.h
index c144577..e469c9d 100644
--- a/src/lights.h
+++ b/src/lights.h
@@ -100,6 +100,8 @@ class RectLight: public Light {
int xSubd = 3, ySubd = 3;
float scaleFactor;
double m_area;
+
+ Vector pts[4];
public:
void fillProperties(ParsedBlock& pb) override
{
diff --git a/src/main.cpp b/src/main.cpp
index 5af773d..f0a71e5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -379,7 +379,7 @@ bool renderStatic()
return render(true);
}
-const char* DEFAULT_SCENE = "data/smallpt.hexray";
+const char* DEFAULT_SCENE = "data/hw12/sphtri.hexray";
int main(int argc, char** argv)
{
diff --git a/src/vector.h b/src/vector.h
index ed4c8cf..149d173 100644
--- a/src/vector.h
+++ b/src/vector.h
@@ -205,3 +205,7 @@ inline std::pair<Vector, Vector> othonormedBasis(const Vector& v)
result.second = result.first ^ v;
return result;
}
+
+inline double radBetween(const Vector& a, const Vector& b) {
+ return acos(dot(normalize(a), normalize(b)));
+}
--
2.42.0
|
