// alternative to base.HitTest(rayWS, ref hits);
protected bool MyHitTest(Ray rayWS, ref List <HitTestResult> hits)
{
LineGeometry3D lineGeometry3D = this.Geometry as LineGeometry3D;
Viewport3DX viewport = FindVisualAncestor <Viewport3DX>(this.renderHost as DependencyObject);
if (this.Visibility == System.Windows.Visibility.Collapsed ||
this.IsHitTestVisible == false ||
viewport == null ||
lineGeometry3D == null)
{
return(false);
}
var result = new HitTestResult {
IsValid = false, Distance = double.MaxValue
};
var lastDist = double.MaxValue;
var index = 0;
foreach (var line in lineGeometry3D.Lines)
{
var t0 = Vector3.TransformCoordinate(line.P0, this.ModelMatrix);
var t1 = Vector3.TransformCoordinate(line.P1, this.ModelMatrix);
Vector3 sp, tp;
float sc, tc;
var distance = GetRayToLineDistance(rayWS, t0, t1, out sp, out tp, out sc, out tc);
var svpm = viewport.GetScreenViewProjectionMatrix();
Vector4 sp4;
Vector4 tp4;
Vector3.Transform(ref sp, ref svpm, out sp4);
Vector3.Transform(ref tp, ref svpm, out tp4);
var sp3 = sp4.ToVector3();
var tp3 = tp4.ToVector3();
var tv2 = new Vector2(tp3.X - sp3.X, tp3.Y - sp3.Y);
var dist = tv2.Length();
if (dist < lastDist && dist <= this.HitTestThickness)
{
lastDist = dist;
result.PointHit = sp.ToPoint3D();
result.NormalAtHit = (sp - tp).ToVector3D(); // not normalized to get length
result.Distance = distance;
result.ModelHit = this;
result.IsValid = true;
result.Tag = index; // ToDo: LineHitTag with additional info
}
index++;
}
if (result.IsValid)
{
hits.Add(result);
}
this.hResult = result;
return(result.IsValid);
}
private static Ray Point2DToRay(this Viewport3DX viewport, Vector2 point2D)
{
var camera = viewport.Camera as ProjectionCamera;
if (camera != null)
{
var p = new Vector3(point2D.X, point2D.Y, 1);
var vp = viewport.GetScreenViewProjectionMatrix();
var vpi = Matrix.Invert(vp);
var test = 1f / ((p.X * vpi.M14) + (p.Y * vpi.M24) + (p.Z * vpi.M34) + vpi.M44);
if (double.IsInfinity(test))
{
vpi.M44 = vpi.M44 + 0.000001f;
}
var worldToModelMatrix = WorldToModelMatrix();
p.Z = 0;
var zn = Vector3.TransformCoordinate(p, vpi);
zn = Vector3.TransformCoordinate(zn, worldToModelMatrix);
p.Z = 1;
var zf = Vector3.TransformCoordinate(p, vpi);
zf = Vector3.TransformCoordinate(zf, worldToModelMatrix);
Vector3 r = zf - zn;
r.Normalize();
if (camera is PerspectiveCamera)
{
var pos = Vector3.TransformCoordinate(camera.Position.ToVector3(), worldToModelMatrix);
return(new Ray(pos, r));
}
if (camera is OrthographicCamera)
{
return(new Ray(zn, r));
}
}
throw new HelixToolkitException("Unproject camera error.");
}
public static Matrix3D GetScreenViewProjectionMatrix3D(this Viewport3DX viewport)
{
return(viewport.GetScreenViewProjectionMatrix().ToMatrix3D());
}
