// convenience function to construct a IntrRay3Triangle3 object for a mesh triangle
public static IntrRay3Triangle3 TriangleIntersection(NGonsCore.geometry3Sharp.mesh.DMesh3 mesh, int ti, Ray3d ray)
{
if (!mesh.IsTriangle(ti))
{
return(null);
}
Triangle3d tri = new Triangle3d();
mesh.GetTriVertices(ti, ref tri.V0, ref tri.V1, ref tri.V2);
IntrRay3Triangle3 q = new IntrRay3Triangle3(ray, tri);
q.Find();
return(q);
}
public static int FindHitTriangle_LinearSearch(NGonsCore.geometry3Sharp.mesh.DMesh3 mesh, Ray3d ray)
{
int tNearestID = NGonsCore.geometry3Sharp.mesh.DMesh3.InvalidID;
double fNearestT = double.MaxValue;
Triangle3d tri = new Triangle3d();
foreach (int ti in mesh.TriangleIndices())
{
// [TODO] optimize this
mesh.GetTriVertices(ti, ref tri.V0, ref tri.V1, ref tri.V2);
IntrRay3Triangle3 ray_tri_hit = new IntrRay3Triangle3(ray, tri);
if (ray_tri_hit.Find())
{
if (ray_tri_hit.RayParameter < fNearestT)
{
fNearestT = ray_tri_hit.RayParameter;
tNearestID = ti;
}
}
}
return(tNearestID);
}
IntrRay3Triangle3 find_added_hit(ref Ray3d ray, out int hit_tid)
{
hit_tid = DMesh3.InvalidID;
IntrRay3Triangle3 nearest = null;
double dNearT = double.MaxValue;
Triangle3d tri = new Triangle3d();
foreach (int tid in AddedT)
{
Index3i tv = EditMesh.GetTriangle(tid);
tri.V0 = EditMesh.GetVertex(tv.a);
tri.V1 = EditMesh.GetVertex(tv.b);
tri.V2 = EditMesh.GetVertex(tv.c);
IntrRay3Triangle3 intr = new IntrRay3Triangle3(ray, tri);
if (intr.Find() && intr.RayParameter < dNearT)
{
dNearT = intr.RayParameter;
hit_tid = tid;
nearest = intr;
}
}
return(nearest);
}
// [RMS] this only tests some basic cases...
public static void test_RayBoxIntersect()
{
Random rand = new Random(316136327);
// check that box hit works
for (int ii = 0; ii < 1000; ++ii)
{
// generate random triangle
Triangle3d t = new Triangle3d(rand.PointInRange(10), rand.PointInRange(10), rand.PointInRange(10));
AxisAlignedBox3d bounds = new AxisAlignedBox3d(t.V0);
bounds.Contain(t.V1);
bounds.Contain(t.V2);
Vector3d c = (t.V0 + t.V1 + t.V2) / 3.0;
for (int jj = 0; jj < 1000; ++jj)
{
Vector3d d = rand.Direction();
Ray3d ray = new Ray3d(c - 100 * d, d);
IntrRay3AxisAlignedBox3 bhit = new IntrRay3AxisAlignedBox3(ray, bounds);
Debug.Assert(bhit.Find());
IntrRay3Triangle3 thit = new IntrRay3Triangle3(ray, t);
Debug.Assert(thit.Find());
Debug.Assert(bhit.RayParam0 < thit.RayParameter);
}
}
int N = 100;
for (int ii = 0; ii < N; ++ii)
{
// generate random boxes
Vector3d c = rand.PointInRange(10);
Vector3d e = rand.PositivePoint();
AxisAlignedBox3d aabox = new AxisAlignedBox3d(c - e, c + e);
Box3d obox = new Box3d(c, Vector3d.AxisX, Vector3d.AxisY, Vector3d.AxisZ, e);
double r = aabox.DiagonalLength;
// center-out tests
for (int jj = 0; jj < N; ++jj)
{
Ray3d ray = new Ray3d(c, rand.Direction());
assert_same_hit(aabox, obox, ray, true);
}
// outside-in tests
for (int jj = 0; jj < N; ++jj)
{
Vector3d p = c + 2 * r * rand.Direction();
Ray3d ray = new Ray3d(p, (c - p).Normalized);
assert_same_hit(aabox, obox, ray, true);
}
}
// random rays
int hits = 0;
int InnerN = 1000;
for (int ii = 0; ii < N; ++ii)
{
// generate random boxe
Vector3d c = rand.PointInRange(10);
Vector3d e = rand.PositivePoint();
// every tenth box, set an axis to degenerate
if (ii % 10 == 0)
{
e[rand.Next() % 3] = 0;
}
AxisAlignedBox3d aabox = new AxisAlignedBox3d(c - e, c + e);
Box3d obox = new Box3d(c, Vector3d.AxisX, Vector3d.AxisY, Vector3d.AxisZ, e);
double r = aabox.DiagonalLength;
TrivialBox3Generator boxgen = new TrivialBox3Generator()
{
Box = obox
};
boxgen.Generate();
DMesh3 mesh = new DMesh3();
boxgen.MakeMesh(mesh);
for (int i = 0; i < InnerN; ++i)
{
Vector3d target = c + rand.PointInRange(r);
Vector3d o = c + rand.PointInRange(10 * r);
Ray3d ray = new Ray3d(o, (target - o).Normalized);
assert_same_hit(aabox, obox, ray, false);
int hitT = MeshQueries.FindHitTriangle_LinearSearch(mesh, ray);
bool bMeshHit = (hitT != DMesh3.InvalidID);
if (bMeshHit)
{
++hits;
}
IntrRay3AxisAlignedBox3 aabbhit = new IntrRay3AxisAlignedBox3(ray, aabox);
Debug.Assert(aabbhit.Find() == bMeshHit);
Debug.Assert(aabbhit.Test() == bMeshHit);
}
}
System.Console.WriteLine("hit {0} of {1} rays", hits, N * InnerN);
}