/// <summary>
/// Initializes a new instance of the <see cref="MeshPoint" /> class.
/// </summary>
/// <param name="point">3D Point.</param>
/// <param name="face">Mesh face.</param>
public MeshPoint(MeshFace face, Point3d point)
{
var adj = face.AdjacentVertices();
var bary = Convert.Point3dToBarycentric(point, adj[0], adj[1], adj[2]);
this.U = bary[0];
this.V = bary[1];
this.W = bary[2];
}
/// <summary>
/// Compute the level on a specified face.
/// </summary>
/// <param name="valueKey">Key of the value to be computed per vertex.</param>
/// <param name="level">Level value to be computed.</param>
/// <param name="face">Face to compute the level in.</param>
/// <param name="line">Resulting level line on the face.</param>
/// <returns>True if successful, false if not.</returns>
public static bool GetFaceLevel(string valueKey, double level, MeshFace face, out Line line)
{
var adj = face.AdjacentVertices();
var vertexValues = new List <double>
{
adj[0].UserValues[valueKey],
adj[1].UserValues[valueKey],
adj[2].UserValues[valueKey]
};
var above = new List <int>();
var below = new List <int>();
for (var i = 0; i < vertexValues.Count; i++)
{
if (vertexValues[i] < level)
{
below.Add(i);
}
else
{
above.Add(i);
}
}
if (above.Count == 3 || below.Count == 3)
{
// Triangle is above or below level
line = new Line(new Point3d(), new Point3d());
return(false);
}
// Triangle intersects level
var intersectionPoints = new List <Point3d>();
foreach (var i in above)
{
foreach (var j in below)
{
var diff = vertexValues[i] - vertexValues[j];
var desiredDiff = level - vertexValues[j];
var unitizedDistance = desiredDiff / diff;
var edgeV = adj[i] - adj[j];
var levelPoint = adj[j] + edgeV * unitizedDistance;
intersectionPoints.Add(levelPoint);
}
}
line = new Line(intersectionPoints[0], intersectionPoints[1]);
return(true);
}
/// <summary>
/// Compute the level on a specified face.
/// </summary>
/// <param name="valueKey">Key of the value to be computed per vertex.</param>
/// <param name="level">Level value to be computed.</param>
/// <param name="face">Face to computee the level in.</param>
/// <param name="line">Resulting level line on the face.</param>
/// <returns>True if successful, false if not.</returns>
public static bool GetFaceLevel(string valueKey, double level, MeshFace face, out Line line)
{
List <MeshVertex> adj = face.AdjacentVertices();
List <double> vertexValues = new List <double> {
adj[0].UserValues[valueKey], adj[1].UserValues[valueKey], adj[2].UserValues[valueKey]
};
List <int> above = new List <int>();
List <int> below = new List <int>();
for (int i = 0; i < vertexValues.Count; i++)
{
if (vertexValues[i] < level)
{
below.Add(i);
}
else
{
above.Add(i);
}
}
if (above.Count == 3 || below.Count == 3)
{
// Triangle is above or below level
line = new Line(new Point3d(), new Point3d());
return(false);
}
else
{
// Triangle intersects level
List <Point3d> intersectionPoints = new List <Point3d>();
foreach (int i in above)
{
foreach (int j in below)
{
double diff = vertexValues[i] - vertexValues[j];
double desiredDiff = level - vertexValues[j];
double unitizedDistance = desiredDiff / diff;
Vector3d edgeV = adj[i] - adj[j];
Point3d levelPoint = (Point3d)adj[j] + (edgeV * unitizedDistance);
intersectionPoints.Add(levelPoint);
}
}
line = new Line(intersectionPoints[0], intersectionPoints[1]);
return(true);
}
}
/// <summary>
/// Compute the gradient on a given mesh face given some per-vertex values.
/// </summary>
/// <param name="valueKey">Key of the values in the vertex.UserData dictionary.</param>
/// <param name="face">Face to compute thee gradient.</param>
/// <returns>A vector representing the gradient on that mesh face.</returns>
public static Vector3d ComputeFaceGradient(string valueKey, MeshFace face)
{
List <MeshVertex> adjacentVertices = face.AdjacentVertices();
Point3d i = adjacentVertices[0];
Point3d j = adjacentVertices[1];
Point3d k = adjacentVertices[2];
double gi = adjacentVertices[0].UserValues[valueKey];
double gj = adjacentVertices[1].UserValues[valueKey];
double gk = adjacentVertices[2].UserValues[valueKey];
Vector3d faceNormal = face.Normal / (2 * face.Area);
Vector3d rotatedGradient = ((gi * (k - j)) + (gj * (i - k)) + (gk * (j - i))) / (2 * face.Area);
Vector3d gradient = rotatedGradient.Cross(faceNormal);
return(gradient);
}
/// <summary>
/// Compute the gradient on a given mesh face given some per-vertex values.
/// </summary>
/// <param name="valueKey">Key of the values in the vertex.UserData dictionary.</param>
/// <param name="face">Face to compute thee gradient.</param>
/// <returns>A vector representing the gradient on that mesh face.</returns>
public static Vector3d ComputeFaceGradient(string valueKey, MeshFace face)
{
var adjacentVertices = face.AdjacentVertices();
Point3d i = adjacentVertices[0];
Point3d j = adjacentVertices[1];
Point3d k = adjacentVertices[2];
var gi = adjacentVertices[0].UserValues[valueKey];
var gj = adjacentVertices[1].UserValues[valueKey];
var gk = adjacentVertices[2].UserValues[valueKey];
var faceNormal = face.Normal / (2 * face.Area);
var rotatedGradient = (gi * (k - j) + gj * (i - k) + gk * (j - i)) / (2 * face.Area);
var gradient = rotatedGradient.Cross(faceNormal);
return(gradient);
}
/// <summary>
/// Compute the intersection between a mesh face perimeter and a ray tangent to the face.
/// </summary>
/// <param name="ray">The tangent ray.</param>
/// <param name="face">The mesh face.</param>
/// <param name="result">The resulting intersection point.</param>
/// <param name="halfEdge">The half-edge on where the intersection lies.</param>
/// <returns>Intersection result.</returns>
public static ISRayFacePerimeter RayFacePerimeter(Ray ray, MeshFace face, out Point3d result, out MeshHalfEdge halfEdge)
{
Vector3d faceNormal = MeshGeometry.FaceNormal(face);
Vector3d biNormal = Vector3d.CrossProduct(ray.Direction, faceNormal);
Plane perpPlane = new Plane(ray.Origin, ray.Direction, faceNormal, biNormal);
List <MeshVertex> vertices = face.AdjacentVertices();
Point3d temp = new Point3d();
Line line = new Line(vertices[0], vertices[1]);
if (LinePlane(line, perpPlane, out temp) != ISLinePlane.Point)
{
result = null;
halfEdge = null;
return(ISRayFacePerimeter.Point);
} // No intersection found
if (temp != ray.Origin && temp != null)
{
result = temp;
halfEdge = null;
return(ISRayFacePerimeter.Point);
} // Intersection found
line = new Line(vertices[1], vertices[2]);
if (LinePlane(line, perpPlane, out temp) != ISLinePlane.Point)
{
result = null;
halfEdge = null;
return(ISRayFacePerimeter.NoIntersection);
} // No intersection found
if (temp != ray.Origin && temp != null)
{
result = temp;
halfEdge = null;
return(ISRayFacePerimeter.Point);
} // Intersection found
line = new Line(vertices[2], vertices[0]);
if (LinePlane(line, perpPlane, out temp) != ISLinePlane.Point)
{
result = null;
halfEdge = null;
return(ISRayFacePerimeter.NoIntersection);
}
if (temp != ray.Origin && temp != null)
{
result = temp;
halfEdge = null;
return(ISRayFacePerimeter.Point);
}
else
{
result = null;
halfEdge = null;
return(ISRayFacePerimeter.Error);
}
}
/// <summary>
/// Compute the intersection between a mesh face perimeter and a ray tangent to the face.
/// </summary>
/// <param name="ray">The tangent ray.</param>
/// <param name="face">The mesh face.</param>
/// <param name="result">The resulting intersection point.</param>
/// <param name="halfEdge">The half-edge on where the intersection lies.</param>
/// <returns>Intersection result.</returns>
public static RayFacePerimeterIntersectionStatus RayFacePerimeter(
Ray ray,
MeshFace face,
out Point3d result,
out MeshHalfEdge halfEdge)
{
var faceNormal = MeshGeometry.FaceNormal(face);
var biNormal = Vector3d.CrossProduct(ray.Direction, faceNormal);
var perpPlane = new Plane(ray.Origin, ray.Direction, faceNormal, biNormal);
var vertices = face.AdjacentVertices();
var temp = new Point3d();
var line = new Line(vertices[0], vertices[1]);
if (LinePlane(line, perpPlane, out temp) != LinePlaneIntersectionStatus.Point)
{
result = null;
halfEdge = null;
return(RayFacePerimeterIntersectionStatus.Point);
} // No intersection found
if (temp != ray.Origin && temp != null)
{
result = temp;
halfEdge = null;
return(RayFacePerimeterIntersectionStatus.Point);
} // Intersection found
line = new Line(vertices[1], vertices[2]);
if (LinePlane(line, perpPlane, out temp) != LinePlaneIntersectionStatus.Point)
{
result = null;
halfEdge = null;
return(RayFacePerimeterIntersectionStatus.NoIntersection);
}
if (temp != ray.Origin && temp != null)
{
result = temp;
halfEdge = null;
return(RayFacePerimeterIntersectionStatus.Point);
}
line = new Line(vertices[2], vertices[0]);
if (LinePlane(line, perpPlane, out temp) != LinePlaneIntersectionStatus.Point)
{
result = null;
halfEdge = null;
return(RayFacePerimeterIntersectionStatus.NoIntersection);
}
if (temp != ray.Origin && temp != null)
{
result = temp;
halfEdge = null;
return(RayFacePerimeterIntersectionStatus.Point);
}
result = null;
halfEdge = null;
return(RayFacePerimeterIntersectionStatus.Error);
}
