/**
* operating with 3-vectors here because there are a lot of cross products
*/
double Triangle::intersection(const ray &viewRay)const {
Vector4d edge1 = p2 - p1;
Vector4d edge2 = p3 - p1;
Vector4d h = cross(viewRay.dir, edge2);
double a = edge1.dot(h);
if (a > -EPSILON && a < EPSILON)
return -1 * std::numeric_limits<double>::max();
double f = 1/a;
Vector4d s = viewRay.orig - p1;
double u = f * s.dot(h);
if (u < 0.0 || u > 1.0)
return -1 * std::numeric_limits<double>::max();
Vector4d q = cross(s, edge1);
double v = f * q.dot(viewRay.dir);
if (v < 0.0 || u + v > 1.0)
return -1 * std::numeric_limits<double>::max();
double t = f * edge2.dot(q);
return t;
}
double geometric(Vector4d s1, Vector4d n1, Vector4d s2, Vector4d n2) {
ASSERT(isUnitVector(n1), "assumes the normals are normalized");
ASSERT(isUnitVector(n2), "assumes the normals are normalized");
Vector4d segment = s1 - s2;
Vector4d seg_dir = segment.normalized();
double cos1 = n1.dot(seg_dir);
double cos2 = n2.dot(-1 * seg_dir);
return std::abs(cos1 * cos2) / segment.squaredNorm();
}
inline bool cullSphere(const Vector4d& center,
double radius) const
{
return (center.z() - radius > m_nearZ ||
center.z() + radius < m_farZ ||
center.dot(m_planeNormals[0]) < -radius ||
center.dot(m_planeNormals[1]) < -radius ||
center.dot(m_planeNormals[2]) < -radius ||
center.dot(m_planeNormals[3]) < -radius);
}
Vector4d CProxyCamera::intersect(const Vector4d &coord, const Vector4d& abcd) const
{
Vector4d ray = m_center - coord;
const double A = coord.dot(abcd);
const double B = ray.dot(abcd);
if (fabs(B)<1e-8)
return Vector4d(0.0f, 0.0f, 0.0f, -1.0f);
else
return coord - A / B * ray;
}
// Test a point to see if it lies within the frustum defined by
// planes z=nearZ, z=farZ, and the four side planes with specified
// normals.
static inline bool frustumCull(const Vector4d& curvePoint,
double curveBoundingRadius,
double nearZ, double farZ,
const Vector4d viewFrustumPlaneNormals[])
{
return (curvePoint.z() - curveBoundingRadius > nearZ ||
curvePoint.z() + curveBoundingRadius < farZ ||
curvePoint.dot(viewFrustumPlaneNormals[0]) < -curveBoundingRadius ||
curvePoint.dot(viewFrustumPlaneNormals[1]) < -curveBoundingRadius ||
curvePoint.dot(viewFrustumPlaneNormals[2]) < -curveBoundingRadius ||
curvePoint.dot(viewFrustumPlaneNormals[3]) < -curveBoundingRadius);
}
std::tuple<double, double> Triangle::uvCoords(const Vector4d &point) const {
Vector4d edge1 = p2 - p1;
Vector4d edge2 = p3 - p1;
Vector4d h = cross(trueNormal, edge2);
double a = edge1.dot(h);
double f = 1/a;
Vector4d s = point - p1;
double u = f * s.dot(h);
Vector4d q = cross(s, edge1);
double v = f * q.dot(trueNormal);
return std::make_tuple(u, v);
}
