Geometry::HitResult<double> Section::
intersectRay(const Geometry::Ray<double,3>& ray) const
{
/* based on "Fast, Minimum Storage Ray/Triangle Intersection" by Tomas
Moeller and Ben Trumbore */
Geometry::Vector<double,3> rayOrig(ray.getOrigin()[0],ray.getOrigin()[1],ray.getOrigin()[2]);
const Geometry::Vector<double,3>& rayDir = ray.getDirection();
/* begin calculating determinant - also used to calculate U parameter */
Geometry::Vector<double,3> pvec = Geometry::cross(rayDir, end);
/* if determinant is near zero, ray lies in plane of triangle */
Scalar det = start * pvec;
if (det>-EPSILON && det<EPSILON)
return Geometry::HitResult<double>();
Scalar invDet = Scalar(1) / det;
/* calculate U parameter and test bounds */
Scalar u = (rayOrig*pvec) * invDet;
if (u < Scalar(0))
return Geometry::HitResult<double>();
/* prepare to test V parameter */
Geometry::Vector<double,3> qvec = Geometry::cross(rayOrig, start);
/* calculate V parameter and test bounds */
Scalar v = (rayDir*qvec) * invDet;
if (v < Scalar(0))
return Geometry::HitResult<double>();
/* calculate t, ray intersects triangle */
Scalar t = (end*qvec) * invDet;
return Geometry::HitResult<double>(t);
}
Geometry::HitResult<double> Section::
intersectPlane(const Geometry::Ray<double,3>& ray, bool cullBackFace) const
{
Geometry::Vector<double,3> rayOrig(ray.getOrigin()[0],ray.getOrigin()[1],ray.getOrigin()[2]);
const Geometry::Vector<double,3>& rayDir = ray.getDirection();
/* the ray intersects the plane at poing t for which (ray(t)-PlaneOrigin) is
orthogonal to the normal. See http://softsurfer.com/Archive/algorithm_0104/algorithm_0104B.htm#Line-Plane Intersection
for nice description */
double nDotDir = normal * rayDir;
//exit on back-facing planes if so desired
if (cullBackFace && nDotDir>0.0)
return Geometry::HitResult<double>();
//handle the parallel case
if (nDotDir>-EPSILON && nDotDir<EPSILON)
{
Geometry::Vector<double,3> toOrig = rayOrig - start;
double nDotToOrig = normal * toOrig;
//coincident
if (nDotToOrig>-EPSILON && nDotToOrig<EPSILON)
return Geometry::HitResult<double>(0.0);
//disjoint
else
return Geometry::HitResult<double>();
}
//compute the intersection parameter
return Geometry::HitResult<double>((normal * (start - rayOrig)) / nDotDir);
}
std::vector<vec3> Orthographic::render(std::vector<std::unique_ptr<WorldObject>> &objects,
std::vector<std::unique_ptr<Light>> &lights,
vec2 imageSize, double imageAspectRatio, int aaDepth) {
std::vector<vec3> frameBuffer;
for (int y = 0; y < imageSize.y; y++) {
for (int x = 0; x < imageSize.x; x++) {
vec3 pixel;
std::vector<vec3> aaData;
for (int aay = 0; aay < aaDepth; aay++) {
for (int aax = 0; aax < aaDepth; aax++) {
// normalize ray pos (-> NDC)
// add 0.5 so that the final ray passes through the middle of the pixel
pixel.x = (x + ((1.0 / (aaDepth - 1.0)) * aax)) / imageSize.x;
pixel.y = (y + ((1.0 / (aaDepth - 1.0)) * aay)) / imageSize.y;
// map from [0;1] to [-imageAspectRatio;imageAspectRatio]
pixel.x = 2.0 * pixel.x - 1.0;
pixel.x *= imageAspectRatio;
pixel.y = 1.0 - 2.0 * pixel.y;
double scale = tan(MyMath::degToRad(fov / 2.0));
pixel.x *= scale;
pixel.y *= scale;
vec3 rayOrig(-pixel.x, -pixel.y, 0.0f);
vec3 rayDir(0.0f, 0.0f, -1.0f);
rayDir -= rayOrig;
rayDir = rayDir.normalize();
Ray ray(rayOrig, rayDir);
aaData.push_back(ray.cast(objects, lights, 3));
}
}
vec3 sum;
for (vec3 color : aaData) {
sum += color;
}
sum = sum / aaData.size();
frameBuffer.push_back(sum);
}
}
return frameBuffer;
}
