From e509d231597c9e8257d5fe9482ed23bf6dc90af5 Mon Sep 17 00:00:00 2001
From: Alexander Gauggel <agauggel@uni-koblenz.de>
Date: Wed, 8 Sep 2021 14:59:27 +0200
Subject: [PATCH] [#94] Corrected ray direction computation
---
projects/saf_r/shaders/raytracing.comp | 26 +++++++++++++++++++++-----
projects/saf_r/src/main.cpp | 6 +++---
2 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/projects/saf_r/shaders/raytracing.comp b/projects/saf_r/shaders/raytracing.comp
index 59a10c2a..db7a1852 100644
--- a/projects/saf_r/shaders/raytracing.comp
+++ b/projects/saf_r/shaders/raytracing.comp
@@ -160,11 +160,27 @@ vec3 castRay(const vec3 initialOrigin, const vec3 initialDirection, int max_dept
vec3 computeDirection(ivec2 coord){
- ivec2 outImageRes = imageSize(outImage);
- float fov = pi / 2.f;
- float x = (2 * (float(coord.x) + 0.5f) / float(outImageRes.x) - 1) * tan(fov / 2.f) * outImageRes.x / float(outImageRes.y);
- float y = -(2 * (float(coord.y) + 0.5f) / float(outImageRes.y) - 1) * tan(fov / 2.f);
- vec3 directionViewSpace = normalize(vec3(x, y, 1));
+ ivec2 outImageRes = imageSize(outImage);
+ float fovDegree = 45;
+ float fov = fovDegree * pi / 180;
+
+ vec2 uv = coord / vec2(outImageRes);
+ vec2 ndc = 2 * uv - 1;
+
+ float tanFovHalf = tan(fov / 2.f);
+ float aspectRatio = outImageRes.x / float(outImageRes.y);
+ float x = ndc.x * tanFovHalf * aspectRatio;
+ float y = -ndc.y * tanFovHalf;
+
+ // z component must be chosen so vector length equals 1
+ // setting z=1 and normalizing shortens x and y, changing the fov
+ // the final length must satisfy:
+ // 1 = |v| <=>
+ // 1 = sqrt(x^2 + y^2 + z^2) <=>
+ // 1 = x^2 + y^2 + z^2 <=>
+ // 1 - x^2 - y^2 = z^2 <=>
+ // sqrt(1 - x^2 - y^2) = z
+ vec3 directionViewSpace = vec3(x, y, sqrt(1 - x*x - y*y));
vec3 directionWorldSpace = mat3(viewToWorld) * directionViewSpace;
return directionWorldSpace;
}
diff --git a/projects/saf_r/src/main.cpp b/projects/saf_r/src/main.cpp
index a6319ce3..6078bf5c 100644
--- a/projects/saf_r/src/main.cpp
+++ b/projects/saf_r/src/main.cpp
@@ -99,9 +99,9 @@ int main(int argc, const char** argv) {
//lights for the scene
std::vector<safrScene::Light> lights;
- lights.push_back(safrScene::Light(glm::vec3(-20, 20, 20), 1.5));
- lights.push_back(safrScene::Light(glm::vec3(30, 50, -25), 1.8));
- lights.push_back(safrScene::Light(glm::vec3(30, 20, 30), 1.7));
+ lights.push_back(safrScene::Light(glm::vec3(-20, 20, 20), 1.5));
+ lights.push_back(safrScene::Light(glm::vec3(30, 50, -25), 1.8));
+ lights.push_back(safrScene::Light(glm::vec3(30, 20, 30), 1.7));
//create the raytracer image for rendering
safrScene scene;
vkcv::asset::Texture texData = scene.render(spheres, lights);
--
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