public static List <V3d> ComputeCorners(this Hull3d hull)
{
List <V3d> Corners = new List <V3d>();
int count = hull.PlaneArray.Length;
for (int i0 = 0; i0 < count; i0++)
{
for (int i1 = 0; i1 < count; i1++)
{
for (int i2 = 0; i2 < count; i2++)
{
if (i0 != i1 && i1 != i2 && i0 != i2)
{
V3d temp;
if (hull.PlaneArray[0].Intersects(hull.PlaneArray[i1], hull.PlaneArray[i2], out temp))
{
if (!temp.IsNaN && !temp.AnyInfinity)
{
Corners.Add(temp);
}
}
}
}
}
}
return(Corners);
}
/// <summary>
/// Builds a hull from the given view-projection transformation (left, right, top, bottom, near, far).
/// The normals of the hull planes point to the inside.
/// A point inside the visual hull will have positive height to all planes.
/// </summary>
public static Hull3d GetVisualHull(this Trafo3d vpTrafo)
{
var frustumCorners = new Box3d(-V3d.IIO, V3d.III).ComputeCorners();
//Min, 0 near left bottom
//new V3d(Max.X, Min.Y, Min.Z), 1 near right bottom
//new V3d(Min.X, Max.Y, Min.Z), 2 near left top
//new V3d(Max.X, Max.Y, Min.Z), 3 near right top
//new V3d(Min.X, Min.Y, Max.Z), 4 far left bottom
//new V3d(Max.X, Min.Y, Max.Z), 5 far right bottom
//new V3d(Min.X, Max.Y, Max.Z), 6 far left top
//Max 7 far right top
// use inverse view-projection to get vertices in world space
frustumCorners.Apply(c => vpTrafo.Backward.TransformPosProj(c));
// hull planes should point inward, assume right-handed transformation to build planes
var hull = new Hull3d(new[]
{
new Plane3d(frustumCorners[0], frustumCorners[4], frustumCorners[2]), // left
new Plane3d(frustumCorners[1], frustumCorners[3], frustumCorners[5]), // right
new Plane3d(frustumCorners[2], frustumCorners[6], frustumCorners[3]), // top
new Plane3d(frustumCorners[0], frustumCorners[1], frustumCorners[4]), // bottom
new Plane3d(frustumCorners[0], frustumCorners[2], frustumCorners[1]), // near
new Plane3d(frustumCorners[4], frustumCorners[5], frustumCorners[6]), // far
});
return(hull);
}
public void TransformInto(Trafo3d trafo, ref Hull3d hull)
{
int count = PlaneCount;
var invTr = trafo.Backward.Transposed;
for (int i = 0; i < count; i++)
{
hull.PlaneArray[i]
= new Plane3d(
invTr.TransformDir(PlaneArray[i].Normal).Normalized,
trafo.Forward.TransformPos(PlaneArray[i].Point));
}
}
public Hull3d Transformed(Trafo3d trafo)
{
int count = PlaneCount;
var hull = new Hull3d(count);
var invTr = trafo.Backward.Transposed;
for (int i = 0; i < count; i++)
{
hull.PlaneArray[i]
= new Plane3d(
invTr.TransformDir(PlaneArray[i].Normal).Normalized,
trafo.Forward.TransformPos(PlaneArray[i].Point));
}
return(hull);
}
/// <summary>
/// Returns unordered set of corners of this hull.
/// </summary>
public static HashSet <V3d> ComputeCorners(this Hull3d hull)
{
var corners = new HashSet <V3d>();
int count = hull.PlaneArray.Length;
for (var i0 = 0; i0 < count; i0++)
{
for (var i1 = i0 + 1; i1 < count; i1++)
{
for (var i2 = i1 + 1; i2 < count; i2++)
{
if (hull.PlaneArray[i0].Intersects(hull.PlaneArray[i1], hull.PlaneArray[i2], out V3d temp))
{
if (temp.IsNaN || temp.AnyInfinity)
{
continue;
}
var inside = true;
for (var j = 0; j < count; j++)
{
if (j == i0 || j == i1 || j == i2)
{
continue;
}
var h = hull.PlaneArray[j].Height(temp);
if (h > 0)
{
inside = false; break;
}
}
if (inside)
{
corners.Add(temp);
}
}
}
}
}
return(corners);
}
public FastHull3d(Hull3d hull)
{
Hull = hull;
MinCornerIndexArray = ComputeMinCornerIndexArray(Hull.PlaneArray);
}
public FastHull3d(FastHull3d fastHull)
{
Hull = new Hull3d(fastHull.Hull);
MinCornerIndexArray = fastHull.MinCornerIndexArray.Copy();
}
/// <summary>
/// Create an empty FastHull3d with count planes.
/// </summary>
public FastHull3d(int count)
{
Hull = new Hull3d(count);
MinCornerIndexArray = new int[count];
}
public Hull3d(Hull3d hull)
{
PlaneArray = hull.PlaneArray.Copy();
}
