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Obb intersect ray 

New method


Former-commit-id: 282a82d773f61fcec8026eb4ccb74e8b2de9784f
This commit is contained in:
Gawaboumga 2014-07-04 11:22:47 +02:00
parent 31d54d4706
commit ba7f3606a0
2 changed files with 24 additions and 100 deletions
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2
include/Nazara/Math/Ray.hpp
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@ -34,7 +34,7 @@ template<typename T> class NzRay
NzVector3<T> GetPoint(T lambda) const;
bool Intersect(const NzBox<T>& box, NzVector3<T> * hitPoint = nullptr, NzVector3<T> * hitSecondPoint = nullptr) const;
bool Intersect(const NzOrientedBox<T>& orientedBox, const NzMatrix4<T>& matrix, NzVector3<T> * hitPoint = nullptr, NzVector3<T> * hitSecondPoint = nullptr) const;
bool Intersect(const NzOrientedBox<T>& orientedBox, NzVector3<T> * hitPoint = nullptr, NzVector3<T> * hitSecondPoint = nullptr) const;
bool Intersect(const NzPlane<T>& plane, NzVector3<T> * hitPoint = nullptr) const;
bool Intersect(const NzSphere<T>& sphere, NzVector3<T> * hitPoint = nullptr, NzVector3<T> * hitSecondPoint = nullptr) const;

122
include/Nazara/Math/Ray.inl
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@ -112,113 +112,37 @@ bool NzRay<T>::Intersect(const NzBox<T>& box, NzVector3<T> * hitPoint, NzVector3
}
template<typename T>
bool NzRay<T>::Intersect(const NzOrientedBox<T>& orientedBox, const NzMatrix4<T>& matrix, NzVector3<T> * hitPoint, NzVector3<T> * hitSecondPoint) const
bool NzRay<T>::Intersect(const NzOrientedBox<T>& orientedBox, NzVector3<T> * hitPoint, NzVector3<T> * hitSecondPoint) const
{
// Traduction from http://www.opengl-tutorial.org/miscellaneous/clicking-on-objects/picking-with-custom-ray-obb-function/ written by Arnaud Masserann
NzVector3<T> width = (orientedBox.GetCorner(nzCorner_NearLeftBottom) - orientedBox.GetCorner(nzCorner_FarLeftBottom)).Normalize();
NzVector3<T> height = (orientedBox.GetCorner(nzCorner_FarLeftTop) - orientedBox.GetCorner(nzCorner_FarLeftBottom)).Normalize();
NzVector3<T> depth = (orientedBox.GetCorner(nzCorner_FarRightBottom) - orientedBox.GetCorner(nzCorner_FarLeftBottom)).Normalize();
// Intersection method from Real-Time Rendering and Essential Mathematics for Games
// Construction of the inverse of the matrix who did the rotation -> orthogonal matrix.
NzMatrix4<T> transformation(width.x, height.x, depth.x, F(0.0),
width.y, height.y, depth.y, F(0.0),
width.z, height.z, depth.z, F(0.0),
F(0.0), F(0.0), F(0.0), F(1.0));
T tMin = F(0.0);
T tMax = INFINITY;
// Reduction to aabb problem
NzVector3<T> newOrigin = transformation.Transform(origin);
NzVector3<T> newDirection = transformation.Transform(direction);
NzVector3<T> OBBposition_worldspace(matrix(3, 0), matrix(3, 1), matrix(3, 2));
NzVector3<T> delta = OBBposition_worldspace - origin;
// Test intersection with the 2 planes perpendicular to the OBB's X axis
NzVector3<T> xaxis(matrix(0, 0), matrix(0, 1), matrix(0, 2));
T e = xaxis.DotProduct(delta);
T f = direction.DotProduct(xaxis);
if (std::abs(f) > F(0.0))
{ // Standard case
T t1 = (e + orientedBox.localBox.x) / f; // Intersection with the "left" plane
T t2 = (e + (orientedBox.localBox.x + orientedBox.localBox.width)) / f; // Intersection with the "right" plane
// t1 and t2 now contain distances betwen ray origin and ray-plane intersections
// We want t1 to represent the nearest intersection,
// so if it's not the case, invert t1 and t2
if (t1 > t2)
{ T w = t1; t1 = t2; t2 = w; } // swap t1 and t2
// tMax is the nearest "far" intersection (amongst the X,Y and Z planes pairs)
if (t2 < tMax)
tMax = t2;
// tMin is the farthest "near" intersection (amongst the X,Y and Z planes pairs)
if (t1 > tMin)
tMin = t1;
// And here's the trick :
// If "far" is closer than "near", then there is NO intersection.
// See the images in the tutorials for the visual explanation.
if (tMax < tMin)
return false;
}
else
// Rare case : the ray is almost parallel to the planes, so they don't have any "intersection"
if (-e + orientedBox.localBox.x > F(0.0) || -e + (orientedBox.localBox.x + orientedBox.localBox.width) < F(0.0))
return false;
// Test intersection with the 2 planes perpendicular to the OBB's Y axis
// Exactly the same thing than above.
NzVector3<T> yaxis(matrix(1, 0), matrix(1, 1), matrix(1, 2));
e = yaxis.DotProduct(delta);
f = direction.DotProduct(yaxis);
if (std::abs(f) > F(0.0))
NzVector3<T> tmp, tmp2;
if (NzRay<T>(newOrigin, newDirection).Intersect(NzBox<T>(orientedBox.GetCorner(nzCorner_NearRightTop), orientedBox.GetCorner(nzCorner_FarLeftBottom)), &tmp, &tmp2))
{
if (hitPoint)
{
transformation.Transpose();
hitPoint->Set(transformation.Transform(tmp));
if (hitSecondPoint)
hitSecondPoint->Set(transformation.Transform(tmp2));
}
T t1 = (e + orientedBox.localBox.y) / f;
T t2 = (e + (orientedBox.localBox.y + orientedBox.localBox.height)) / f;
if (t1 > t2)
{ T w = t1; t1 = t2; t2 = w; } // swap t1 and t2
if (t2 < tMax)
tMax = t2;
if (t1 > tMin)
tMin = t1;
if (tMin > tMax)
return false;
return true;
}
else
if (-e + orientedBox.localBox.y > F(0.0) || -e + (orientedBox.localBox.y + orientedBox.localBox.height) < F(0.0))
return false;
// Test intersection with the 2 planes perpendicular to the OBB's Z axis
// Exactly the same thing than above.
NzVector3<T> zaxis(matrix(2, 0), matrix(2, 1), matrix(2, 2));
e = zaxis.DotProduct(delta);
f = direction.DotProduct(zaxis);
if (std::abs(f) > F(0.0))
{
T t1 = (e + orientedBox.localBox.z) / f;
T t2 = (e + (orientedBox.localBox.z + orientedBox.localBox.depth)) / f;
if (t1 > t2)
{ T w = t1; t1 = t2; t2 = w; } // swap t1 and t2
if (t2 < tMax)
tMax = t2;
if (t1 > tMin)
tMin = t1;
if (tMin > tMax)
return false;
}
else
if (-e + orientedBox.localBox.z > F(0.0) || -e + (orientedBox.localBox.z + orientedBox.localBox.depth) < F(0.0))
return false;
if (hitPoint)
hitPoint->Set(GetPoint(tMin));
if (hitSecondPoint)
hitSecondPoint->Set(GetPoint(tMax));
return true;
return false;
}
template<typename T>