//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
// NOTE: Geometry3D hit testing takes the rayParams in the outer space of the
// Geometry3D. That is, RayHitTest() will apply this geometry's
// transform to the ray for the caller.
//
// This is different than Visual hit testing which does not transform
// the hit testing parameters by the Visual's transform.
internal void RayHitTest(RayHitTestParameters rayParams, FaceType facesToHit)
{
Debug.Assert(facesToHit != FaceType.None,
"Caller should make sure we're trying to hit something");
Rect3D bounds = Bounds;
if (bounds.IsEmpty)
{
return;
}
//
Point3D origin;
Vector3D direction;
rayParams.GetLocalLine(out origin, out direction);
if (LineUtil.ComputeLineBoxIntersection(ref origin, ref direction, ref bounds, rayParams.IsRay))
{
RayHitTestCore(rayParams, facesToHit);
}
//
}
internal override void RayHitTestCore(RayHitTestParameters rayParams)
{
Geometry3D geometry = Geometry;
if (geometry != null)
{
// If our Geometry3D hit test intersects anything we should return "this" Model3D
// as the HitTestResult.ModelHit.
rayParams.CurrentModel = this;
FaceType facesToHit = FaceType.None;
if (Material != null)
{
facesToHit |= FaceType.Front;
}
if (BackMaterial != null)
{
facesToHit |= FaceType.Back;
}
if (facesToHit != FaceType.None)
{
geometry.RayHitTest(rayParams, facesToHit);
}
}
}
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
// NOTE: Geometry3D hit testing takes the rayParams in the outer space of the
// Geometry3D. That is, RayHitTest() will apply this geometry's
// transform to the ray for the caller.
//
// This is different than Visual hit testing which does not transform
// the hit testing parameters by the Visual's transform.
internal void RayHitTest(RayHitTestParameters rayParams, FaceType facesToHit)
{
Debug.Assert(facesToHit != FaceType.None,
"Caller should make sure we're trying to hit something");
Rect3D bounds = Bounds;
if (bounds.IsEmpty)
{
return;
}
//
Point3D origin;
Vector3D direction;
rayParams.GetLocalLine(out origin, out direction);
if (LineUtil.ComputeLineBoxIntersection(ref origin, ref direction, ref bounds, rayParams.IsRay))
{
RayHitTestCore(rayParams, facesToHit);
}
//
}
internal override void RayHitTestCore(RayHitTestParameters rayParams)
{
Geometry3D geometry = Geometry;
if (geometry != null)
{
// If our Geometry3D hit test intersects anything we should return "this" Model3D
// as the HitTestResult.ModelHit.
rayParams.CurrentModel = this;
FaceType facesToHit = FaceType.None;
if (Material != null)
{
facesToHit |= FaceType.Front;
}
if (BackMaterial != null)
{
facesToHit |= FaceType.Back;
}
if (facesToHit != FaceType.None)
{
geometry.RayHitTest(rayParams, facesToHit);
}
}
}
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
// NOTE: Geometry3D hit testing takes the rayParams in the outer space of the
// Geometry3D. That is, RayHitTest() will apply this geometry's
// transform to the ray for the caller.
//
// This is different than Visual hit testing which does not transform
// the hit testing parameters by the Visual's transform.
internal void RayHitTest(RayHitTestParameters rayParams, FaceType facesToHit)
{
Debug.Assert(facesToHit != FaceType.None,
"Caller should make sure we're trying to hit something");
Rect3D bounds = Bounds;
if (bounds.IsEmpty)
{
return;
}
// Geometry3D's do not yet support a Transform property
//
// Transform3D transform = Transform;
// rayParams.PushTransform(transform);
Point3D origin;
Vector3D direction;
rayParams.GetLocalLine(out origin, out direction);
if (LineUtil.ComputeLineBoxIntersection(ref origin, ref direction, ref bounds, rayParams.IsRay))
{
RayHitTestCore(rayParams, facesToHit);
}
// Geometry3D's do not yet support a Transform property
//
// rayParams.PopTransform(transform);
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
// NOTE: Model3D hit testing takes the rayParams in the outer space of the
// Model3D. That is, RayHitTest() will apply this model's transform
// to the ray for the caller.
//
// This is different than Visual hit testing which does not transform
// the hit testing parameters by the Visual's transform.
internal void RayHitTest(RayHitTestParameters rayParams)
{
Transform3D transform = Transform;
rayParams.PushModelTransform(transform);
RayHitTestCore(rayParams);
rayParams.PopTransform(transform);
}
public void HitTest(object sender, System.Windows.Input.MouseButtonEventArgs args)
{
Point mouseposition = args.GetPosition(myViewport);
Point3D testpoint3D = new Point3D(mouseposition.X, mouseposition.Y, 0);
Vector3D testdirection = new Vector3D(mouseposition.X, mouseposition.Y, 10);
PointHitTestParameters pointparams = new PointHitTestParameters(mouseposition);
RayHitTestParameters rayparams = new RayHitTestParameters(testpoint3D, testdirection);
//test for a result in the Viewport3D
VisualTreeHelper.HitTest(myViewport, null, HTResult, pointparams);
UpdateTestPointInfo(testpoint3D, testdirection);
}
public Point3D? HitTest(Visual3D reference, Point3D point, Vector3D direction)
{
if (reference != null)
{
var hitParams = new RayHitTestParameters(point, direction);
hit = false;
VisualTreeHelper.HitTest(reference, null, HitTestCallback, hitParams);
if (hit)
{
return hitTestValue;
}
}
return null;
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
internal override void RayHitTestCore(
RayHitTestParameters rayParams)
{
Model3DCollection children = Children;
if (children == null)
{
return;
}
for (int i = children.Count - 1; i >= 0; i--)
{
Model3D child = children.Internal_GetItem(i);
// Perform the hit-test against the child.
child.RayHitTest(rayParams);
}
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
internal override void RayHitTestCore(
RayHitTestParameters rayParams)
{
Model3DCollection children = Children;
if (children == null)
{
return;
}
for (int i = children.Count - 1; i >= 0; i--)
{
Model3D child = children.Internal_GetItem(i);
// Perform the hit-test against the child.
child.RayHitTest(rayParams);
}
}
internal override HitTestResultBehavior HitTestPointInternal(
HitTestFilterCallback filterCallback,
HitTestResultCallback resultCallback,
PointHitTestParameters hitTestParameters)
{
if (_children.Count != 0)
{
double distanceAdjustment;
RayHitTestParameters rayParams =
Camera.RayFromViewportPoint(
hitTestParameters.HitPoint,
Viewport.Size,
BBoxSubgraph,
out distanceAdjustment);
HitTestResultBehavior result = Visual3D.HitTestChildren(filterCallback, rayParams, this);
return(rayParams.RaiseCallback(resultCallback, filterCallback, result, distanceAdjustment));
}
return(HitTestResultBehavior.Continue);
}
/// <summary>
/// This overload is for actually dragging a part around
/// </summary>
/// <remarks>
/// The centerRay is the ray that goes through the middle of the part being dragged around. The return point is where
/// the center of the part will go, and is calculated as an offset from the click ray
/// </remarks>
public Point3D? CastRay(RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
Point3D? retVal = null;
switch (_shape)
{
case ShapeType.Line:
double dummy1;
retVal = CastRay_Line(out dummy1, _point, _direction, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.Lines:
retVal = CastRay_LinesCircles(_lines, null, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.Plane:
retVal = CastRay_Plane(_plane, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.Circle:
double dummy2;
retVal = CastRay_Circle(out dummy2, _plane, _point, _radius, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.Circles:
retVal = CastRay_LinesCircles(null, _circles, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.LinesCircles:
retVal = CastRay_LinesCircles(_lines, _circles, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.Cylinder:
retVal = CastRay_Cylinder(_point, _direction, _radius, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.Sphere:
retVal = CastRay_Sphere(_point, _radius, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
break;
case ShapeType.Mesh:
throw new ApplicationException("finish this");
case ShapeType.None:
retVal = null;
break;
default:
throw new ApplicationException("Unknown ShapeType: " + _shape.ToString());
}
return retVal;
}
/// <summary>
/// This overload is a straight ray cast, nothing extra
/// </summary>
public Point3D? CastRay(RayHitTestParameters ray)
{
Point3D? retVal = null;
switch (_shape)
{
case ShapeType.Line:
#region Line
Point3D? point1, point2;
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, _point, _direction, ray.Origin, ray.Direction))
{
retVal = point1.Value;
}
#endregion
break;
case ShapeType.Lines:
#region Lines
retVal = CastRay_LinesCircles(_lines, null, ray);
#endregion
break;
case ShapeType.Plane:
#region Plane
retVal = Math3D.GetIntersection_Plane_Line(_plane, ray.Origin, ray.Direction);
#endregion
break;
case ShapeType.Circle:
#region Circle
Point3D[] nearestCirclePoints, nearestLinePoints;
if (Math3D.GetClosestPoints_Circle_Line(out nearestCirclePoints, out nearestLinePoints, _plane, _point, _radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay))
{
retVal = nearestCirclePoints[0];
}
#endregion
break;
case ShapeType.Circles:
#region Circles
retVal = CastRay_LinesCircles(null, _circles, ray);
#endregion
break;
case ShapeType.LinesCircles:
#region LinesCircles
retVal = CastRay_LinesCircles(_lines, _circles, ray);
#endregion
break;
case ShapeType.Cylinder:
#region Cylinder
Point3D[] nearestCylinderPoints, nearestLinePoints2;
if (Math3D.GetClosestPoints_Cylinder_Line(out nearestCylinderPoints, out nearestLinePoints2, _point, _direction, _radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay))
{
retVal = nearestCylinderPoints[0];
}
#endregion
break;
case ShapeType.Sphere:
#region Sphere
Point3D[] nearestSpherePoints, nearestLinePoints3;
Math3D.GetClosestPoints_Sphere_Line(out nearestSpherePoints, out nearestLinePoints3, _point, _radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay);
{
retVal = nearestSpherePoints[0];
}
#endregion
break;
case ShapeType.Mesh:
throw new ApplicationException("finish this");
case ShapeType.None:
retVal = null;
break;
default:
throw new ApplicationException("Unknown ShapeType: " + _shape.ToString());
}
return retVal;
}
//
// Hits the ray against the mesh
//
internal override void RayHitTestCore(
RayHitTestParameters rayParams,
FaceType hitTestableFaces)
{
Debug.Assert(hitTestableFaces != FaceType.None,
"Caller should make sure we're trying to hit something");
Point3DCollection positions = Positions;
if (positions == null)
{
return;
}
Point3D origin;
Vector3D direction;
rayParams.GetLocalLine(out origin, out direction);
Int32Collection indices = TriangleIndices;
// In the line case, we want to hit test all faces because we don't
// have a direction. This may differ from what faces we want to
// accept.
FaceType facesToHit;
if (rayParams.IsRay)
{
facesToHit = hitTestableFaces;
}
else
{
facesToHit = FaceType.Front | FaceType.Back;
}
//
// This code duplication is unfortunate but necessary. Breaking it down into methods
// further significantly impacts performance. About 5% improvement could be made
// by unrolling this code below even more.
//
// If futher perf investigation is done with this code, be sure to test NGEN assemblies only
// as JIT produces different, faster code than NGEN.
//
if (indices == null || indices.Count == 0)
{
FrugalStructList <Point3D> ps = positions._collection;
int count = ps.Count - (ps.Count % 3);
for (int i = count - 1; i >= 2; i -= 3)
{
int i0 = i - 2;
int i1 = i - 1;
int i2 = i;
Point3D v0 = ps[i0];
Point3D v1 = ps[i1];
Point3D v2 = ps[i2];
double hitTime;
Point barycentric;
// The line hit test is equivalent to a double sided
// triangle hit because it doesn't cull triangles based
// on winding
if (LineUtil.ComputeLineTriangleIntersection(
facesToHit,
ref origin,
ref direction,
ref v0,
ref v1,
ref v2,
out barycentric,
out hitTime
)
)
{
if (rayParams.IsRay)
{
ValidateRayHit(
rayParams,
ref origin,
ref direction,
hitTime,
i0,
i1,
i2,
ref barycentric
);
}
else
{
ValidateLineHit(
rayParams,
hitTestableFaces,
i0,
i1,
i2,
ref v0,
ref v1,
ref v2,
ref barycentric
);
}
}
}
}
else // indexed mesh
{
FrugalStructList <Point3D> ps = positions._collection;
FrugalStructList <int> idcs = indices._collection;
int count = idcs.Count;
int limit = ps.Count;
for (int i = 2; i < count; i += 3)
{
int i0 = idcs[i - 2];
int i1 = idcs[i - 1];
int i2 = idcs[i];
// Quit if we encounter an index out of range.
// This is okay because the triangles we ignore are not rendered.
// (see: CMilMeshGeometry3DDuce::Realize)
if ((0 > i0 || i0 >= limit) ||
(0 > i1 || i1 >= limit) ||
(0 > i2 || i2 >= limit))
{
break;
}
Point3D v0 = ps[i0];
Point3D v1 = ps[i1];
Point3D v2 = ps[i2];
double hitTime;
Point barycentric;
if (LineUtil.ComputeLineTriangleIntersection(
facesToHit,
ref origin,
ref direction,
ref v0,
ref v1,
ref v2,
out barycentric,
out hitTime
)
)
{
if (rayParams.IsRay)
{
ValidateRayHit(
rayParams,
ref origin,
ref direction,
hitTime,
i0,
i1,
i2,
ref barycentric
);
}
else
{
ValidateLineHit(
rayParams,
hitTestableFaces,
i0,
i1,
i2,
ref v0,
ref v1,
ref v2,
ref barycentric
);
}
}
}
}
}
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
//
// Processes a ray-triangle intersection to see if it's a valid hit. Unnecessary faces
// have already been culled by the ray-triange intersection routines.
//
// Shares some code with ValidateLineHit
//
private void ValidateRayHit(
RayHitTestParameters rayParams,
ref Point3D origin,
ref Vector3D direction,
double hitTime,
int i0,
int i1,
int i2,
ref Point barycentric
)
{
if (hitTime > 0)
{
Matrix3D worldTransformMatrix = rayParams.HasWorldTransformMatrix ? rayParams.WorldTransformMatrix : Matrix3D.Identity;
Point3D pointHit = origin + hitTime * direction;
Point3D worldPointHit = pointHit;
worldTransformMatrix.MultiplyPoint(ref worldPointHit);
// If we have a HitTestProjectionMatrix than this hit test originated
// at a Viewport3DVisual.
if (rayParams.HasHitTestProjectionMatrix)
{
// To test if we are in front of the far clipping plane what we
// do conceptually is project our hit point in world space into
// homogenous space and verify that it is on the correct side of
// the Z=1 plane.
//
// To save some cycles we only bother computing Z and W of the
// projected point and use a simple Z/W > 1 test to see if we
// are past the far plane.
//
// NOTE: HitTestProjectionMatrix is not just the camera matrices.
// It has an additional translation to move the ray to the
// origin. This extra translation does not effect this test.
Matrix3D m = rayParams.HitTestProjectionMatrix;
// We directly substitute 1 for p.W below:
double pz = worldPointHit.X * m.M13 + worldPointHit.Y * m.M23 + worldPointHit.Z * m.M33 + m.OffsetZ;
double pw = worldPointHit.X * m.M14 + worldPointHit.Y * m.M24 + worldPointHit.Z * m.M34 + m.M44;
// Early exit if pz/pw > 1. The negated logic is to reject NaNs.
if (!(pz / pw <= 1))
{
return;
}
Debug.Assert(!double.IsInfinity(pz / pw) && !double.IsNaN(pz / pw),
"Expected near/far tests to cull -Inf/+Inf and NaN.");
}
double dist = (worldPointHit - rayParams.Origin).Length;
Debug.Assert(dist > 0, "Distance is negative: " + dist);
if (rayParams.HasModelTransformMatrix)
{
rayParams.ModelTransformMatrix.MultiplyPoint(ref pointHit);
}
rayParams.ReportResult(this, pointHit, dist, i0, i1, i2, barycentric);
}
}
internal override RayHitTestParameters RayFromViewportPoint(Point p, Size viewSize, Rect3D boundingRect, out double distanceAdjustment)
{
//
// Compute rayParameters
//
// Find the point on the projection plane in post-projective space where
// the viewport maps to a 2x2 square from (-1,1)-(1,-1).
Point np = M3DUtil.GetNormalizedPoint(p, viewSize);
// This ray is consistent with a left-handed camera
// MatrixCamera should be right-handed and should be updated to be so.
// So (conceptually) the user clicked on the point (np.X,
// np.Y, 0) in post-projection clipping space and the ray
// extends in the direction (0, 0, 1) because our ray
// after projection looks down the positive z axis. We
// need to convert this ray and direction back to world
// space.
Matrix3D worldToCamera = GetViewMatrix() * ProjectionMatrix;
Matrix3D cameraToWorld = worldToCamera;
if (!cameraToWorld.HasInverse)
{
// When the following issue is addressed we should
// investigate if the custom code paths in Orthographic and PerspectiveCamera
// are worth keeping. They may not be buying us anything aside from handling
// singular matrices.
// Need to handle singular matrix cameras
throw new NotSupportedException(SR.Get(SRID.HitTest_Singular));
}
cameraToWorld.Invert();
Point4D origin4D = new Point4D(np.X, np.Y, 0, 1) * cameraToWorld;
Point3D origin = new Point3D(origin4D.X / origin4D.W,
origin4D.Y / origin4D.W,
origin4D.Z / origin4D.W);
// To transform the direction we use the Jacobian of
// cameraToWorld at the point np.X,np.Y,0 that we just
// transformed.
//
// The Jacobian of the homogeneous matrix M is a 3x3 matrix.
//
// Let x be the point we are computing the Jacobian at, and y be the
// result of transforming x by M, i.e.
// (wy w) = (x 1) M
// Where (wy w) is the homogeneous point representing y with w as its homogeneous coordinate
// And (x 1) is the homogeneous point representing x with 1 as its homogeneous coordinate
//
// Then the i,j component of the Jacobian (at x) is
// (M_ij - M_i4 y_j) / w
//
// Since we're only concerned with the direction of the
// transformed vector and not its magnitude, we can scale
// this matrix by a POSITIVE factor. The computation
// below computes the Jacobian scaled by 1/w and then
// after we normalize the final vector we flip it around
// if w is negative.
//
// To transform a vector we just right multiply it by this Jacobian matrix.
//
// Compute the Jacobian at np.X,np.Y,0 ignoring the constant factor of w.
// Here's the pattern
//
// double Jij = cameraToWorld.Mij - cameraToWorld.Mi4 * origin.j
//
// but we only need J31,J32,&J33 because we're only
// transforming the vector 0,0,1
double J31 = cameraToWorld.M31 - cameraToWorld.M34 * origin.X;
double J32 = cameraToWorld.M32 - cameraToWorld.M34 * origin.Y;
double J33 = cameraToWorld.M33 - cameraToWorld.M34 * origin.Z;
// Then multiply that matrix by (0, 0, 1) which is
// the direction of the ray in post-projection space.
Vector3D direction = new Vector3D(J31, J32, J33);
direction.Normalize();
// We multiplied by the Jacobian times W, so we need to
// account for whether that flipped our result or not.
if (origin4D.W < 0)
{
direction = -direction;
}
RayHitTestParameters rayParameters = new RayHitTestParameters(origin, direction);
//
// Compute HitTestProjectionMatrix
//
// The viewportMatrix will take normalized clip space into
// viewport coordinates, with an additional 2D translation
// to put the ray at the origin.
Matrix3D viewportMatrix = new Matrix3D();
viewportMatrix.TranslatePrepend(new Vector3D(-p.X, viewSize.Height - p.Y, 0));
viewportMatrix.ScalePrepend(new Vector3D(viewSize.Width / 2, -viewSize.Height / 2, 1));
viewportMatrix.TranslatePrepend(new Vector3D(1, 1, 0));
// `First world-to-camera, then camera's projection, then normalized clip space to viewport.
rayParameters.HitTestProjectionMatrix =
worldToCamera *
viewportMatrix;
//
// MatrixCamera does not allow for Near/Far plane adjustment, so
// the distanceAdjustment remains 0.
//
distanceAdjustment = 0.0;
return(rayParameters);
}
private static Point3D? CastRay_Cylinder(Point3D point, Vector3D direction, double radius, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
// Get points on the cylinder
Point3D? mouseDownClickPoint = null;
Point3D? mouseDownCenterPoint = null;
Point3D? currentClickPoint = null;
Point3D[] nearestCylinderPoints, nearestLinePoints;
if (Math3D.GetClosestPoints_Cylinder_Line(out nearestCylinderPoints, out nearestLinePoints, point, direction, radius, currentClickRay.Origin, currentClickRay.Direction, Math3D.RayCastReturn.ClosestToRay))
{
currentClickPoint = nearestCylinderPoints[0];
if (Math3D.GetClosestPoints_Cylinder_Line(out nearestCylinderPoints, out nearestLinePoints, point, direction, radius, mouseDownClickRay.Origin, mouseDownClickRay.Direction, Math3D.RayCastReturn.ClosestToRay))
{
mouseDownClickPoint = nearestCylinderPoints[0];
if (Math3D.GetClosestPoints_Cylinder_Line(out nearestCylinderPoints, out nearestLinePoints, point, direction, radius, mouseDownCenterRay.Origin, mouseDownCenterRay.Direction, Math3D.RayCastReturn.ClosestToRay))
{
mouseDownCenterPoint = nearestCylinderPoints[0];
}
}
}
if (mouseDownCenterPoint == null || mouseDownClickPoint == null || currentClickPoint == null)
{
return currentClickPoint; // it doesn't matter if this one is null or not, the offset can't be determined, so just return the raw click value
}
// Circle only cared about an offset angle, but cylinder needs two things:
// Offset line (the part of the offset that is parallel to the cylinder's axis)
// Offset angle (the part of the offset that is perpendicular to the cylinder's axis)
Vector3D offsetLinear = (mouseDownCenterPoint.Value - mouseDownClickPoint.Value).GetProjectedVector(direction);
Quaternion offsetRadial = GetRotation_Circle(point, direction, mouseDownClickPoint.Value, mouseDownCenterPoint.Value);
//TODO: Get the radial offset working as well (sphere is also messed up, the same fix should work for both)
//TODO: See if this is the most effiecient way or not
Transform3DGroup transform = new Transform3DGroup();
//transform.Children.Add(new RotateTransform3D(new QuaternionRotation3D(offsetRadial)));
transform.Children.Add(new TranslateTransform3D(offsetLinear));
//TODO: Bring currentClickPoint into local coords, do the transform, then put it back into global coords
// Find the point along the cylinder's axis that is nearest to the current click. This will become the center of the model coords
Point3D modelCenter = Math3D.GetClosestPoint_Line_Point(point, direction, currentClickPoint.Value);
// Shift the click point into model coords
Vector3D modelClick = currentClickPoint.Value - modelCenter;
// Adjust by the offset transform (needed to put into model coords, because there is a rotation)
modelClick = transform.Transform(modelClick);
// Now put back into world coords
return modelCenter + modelClick;
}
private static Point3D? CastRay_Plane(ITriangle plane, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
// This is the offset along the drag plane from the center to mouse down click
Vector3D offset;
Point3D? mouseDownClickPoint = Math3D.GetIntersection_Plane_Line(plane, mouseDownClickRay.Origin, mouseDownClickRay.Direction);
Point3D? mouseDownCenterPoint = Math3D.GetIntersection_Plane_Line(plane, mouseDownCenterRay.Origin, mouseDownCenterRay.Direction);
if (mouseDownClickPoint != null && mouseDownCenterPoint != null)
{
offset = mouseDownCenterPoint.Value - mouseDownClickPoint.Value;
}
else
{
// The click ray is parallel to the drag plane. This should be extremely rare
offset = new Vector3D(0, 0, 0);
}
// Now that the offset is known, project the current click ray onto the drag plane
Point3D? retVal = Math3D.GetIntersection_Plane_Line(plane, currentClickRay.Origin, currentClickRay.Direction);
if (retVal != null)
{
return retVal.Value + offset;
}
else
{
return null;
}
}
//
// Processes a ray-line intersection to see if it's a valid hit.
//
// Shares some code with ValidateRayHit
//
private void ValidateLineHit(
RayHitTestParameters rayParams,
FaceType facesToHit,
int i0,
int i1,
int i2,
ref Point3D v0,
ref Point3D v1,
ref Point3D v2,
ref Point barycentric
)
{
Matrix3D worldTransformMatrix = rayParams.HasWorldTransformMatrix ? rayParams.WorldTransformMatrix : Matrix3D.Identity;
// OK, we have an intersection with the LINE but that could be wrong on three
// accounts:
// 1. We could have hit the line on the wrong side of the ray's origin.
// 2. We may need to cull the intersection if it's beyond the far clipping
// plane (only if the hit test originated from a Viewport3DVisual.)
// 3. We could have hit a back-facing triangle
// We will transform the hit point back into world space to check these
// things & compute the correct distance from the origin to the hit point.
// Hit point in model space
Point3D pointHit = M3DUtil.Interpolate(ref v0, ref v1, ref v2, ref barycentric);
Point3D worldPointHit = pointHit;
worldTransformMatrix.MultiplyPoint(ref worldPointHit);
// Vector from origin to hit point
Vector3D hitVector = worldPointHit - rayParams.Origin;
Vector3D originalDirection = rayParams.Direction;
double rayDistanceUnnormalized = Vector3D.DotProduct(originalDirection, hitVector);
if (rayDistanceUnnormalized > 0)
{
// If we have a HitTestProjectionMatrix than this hit test originated
// at a Viewport3DVisual.
if (rayParams.HasHitTestProjectionMatrix)
{
// To test if we are in front of the far clipping plane what we
// do conceptually is project our hit point in world space into
// homogenous space and verify that it is on the correct side of
// the Z=1 plane.
//
// To save some cycles we only bother computing Z and W of the
// projected point and use a simple Z/W > 1 test to see if we
// are past the far plane.
//
// NOTE: HitTestProjectionMatrix is not just the camera matrices.
// It has an additional translation to move the ray to the
// origin. This extra translation does not effect this test.
Matrix3D m = rayParams.HitTestProjectionMatrix;
// We directly substitute 1 for p.W below:
double pz = worldPointHit.X * m.M13 + worldPointHit.Y * m.M23 + worldPointHit.Z * m.M33 + m.OffsetZ;
double pw = worldPointHit.X * m.M14 + worldPointHit.Y * m.M24 + worldPointHit.Z * m.M34 + m.M44;
// Early exit if pz/pw > 1. The negated logic is to reject NaNs.
if (!(pz / pw <= 1))
{
return;
}
Debug.Assert(!double.IsInfinity(pz / pw) && !double.IsNaN(pz / pw),
"Expected near/far tests to cull -Inf/+Inf and NaN.");
}
Point3D a = v0, b = v1, c = v2;
worldTransformMatrix.MultiplyPoint(ref a);
worldTransformMatrix.MultiplyPoint(ref b);
worldTransformMatrix.MultiplyPoint(ref c);
Vector3D normal = Vector3D.CrossProduct(b - a, c - a);
double cullSign = -Vector3D.DotProduct(normal, hitVector);
double det = worldTransformMatrix.Determinant;
bool frontFace = (cullSign > 0) == (det >= 0);
if (((facesToHit & FaceType.Front) == FaceType.Front && frontFace) || ((facesToHit & FaceType.Back) == FaceType.Back && !frontFace))
{
double dist = hitVector.Length;
if (rayParams.HasModelTransformMatrix)
{
rayParams.ModelTransformMatrix.MultiplyPoint(ref pointHit);
}
rayParams.ReportResult(this, pointHit, dist, i0, i1, i2, barycentric);
}
}
}
private static Point3D? CastRay_PlaneLimited(ITriangle plane, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay, RayHitTestParameters cameraLook)
{
// They are looking along the plane, so snap to a line instead of a plane
RayHitTestParameters snapLine = CastRay_PlaneLimitedSprtGetSnapLine(plane, cameraLook.Direction); // the returned vector is used like 3 bools, with only one axis set to true
if (snapLine == null)
{
return null;
}
double dummy1;
return CastRay_Line(out dummy1, snapLine.Origin, snapLine.Direction, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
}
internal abstract void RayHitTestCore(RayHitTestParameters rayParams, FaceType hitTestableFaces);
internal override RayHitTestParameters RayFromViewportPoint(Point p, Size viewSize, Rect3D boundingRect, out double distanceAdjustment)
{
// The camera may be animating. Take a snapshot of the current value
// and get the property values we need. (Window OS #992662)
Point3D position = Position;
Vector3D lookDirection = LookDirection;
Vector3D upDirection = UpDirection;
Transform3D transform = Transform;
double zn = NearPlaneDistance;
double zf = FarPlaneDistance;
double fov = M3DUtil.DegreesToRadians(FieldOfView);
//
// Compute rayParameters
//
// Find the point on the projection plane in post-projective space where
// the viewport maps to a 2x2 square from (-1,1)-(1,-1).
Point np = M3DUtil.GetNormalizedPoint(p, viewSize);
// Note: h and w are 1/2 of the inverse of the width/height ratios:
//
// h = 1/(heightDepthRatio) * (1/2)
// w = 1/(widthDepthRatio) * (1/2)
//
// Computation for h is a bit different than what you will find in
// D3DXMatrixPerspectiveFovRH because we have a horizontal rather
// than vertical FoV.
double aspectRatio = M3DUtil.GetAspectRatio(viewSize);
double halfWidthDepthRatio = Math.Tan(fov / 2);
double h = aspectRatio / halfWidthDepthRatio;
double w = 1 / halfWidthDepthRatio;
// To get from projective space to camera space we apply the
// width/height ratios to find our normalized point at 1 unit
// in front of the camera. (1 is convenient, but has no other
// special significance.) See note above about the construction
// of w and h.
Vector3D rayDirection = new Vector3D(np.X / w, np.Y / h, -1);
// Apply the inverse of the view matrix to our rayDirection vector
// to convert it from camera to world space.
//
// NOTE: Because our construction of the ray assumes that the
// viewMatrix translates the position to the origin we pass
// null for the Camera.Transform below and account for it
// later.
Matrix3D viewMatrix = CreateViewMatrix(/* trasform = */ null, ref position, ref lookDirection, ref upDirection);
Matrix3D invView = viewMatrix;
invView.Invert();
invView.MultiplyVector(ref rayDirection);
// The we have the ray direction, now we need the origin. The camera's
// position would work except that we would intersect geometry between
// the camera plane and the near plane so instead we must find the
// point on the project plane where the ray (position, rayDirection)
// intersect (Windows OS #1005064):
//
// | _.> p = camera position
// rd _+" ld = camera look direction
// .-" |ro pp = projection plane
// _.-" | rd = ray direction
// p +"--------+---> ro = desired ray origin on pp
// ld |
// pp
//
// Above we constructed the direction such that it's length projects to
// 1 unit on the lookDirection vector.
//
//
// rd _.>
// .-" rd = unnormalized rayDirection
// _.-" ld = normalized lookDirection (length = 1)
// -"--------->
// ld
//
// So to find the desired rayOrigin on the projection plane we simply do:
Point3D rayOrigin = position + zn * rayDirection;
rayDirection.Normalize();
// Account for the Camera.Transform we ignored during ray construction above.
if (transform != null && transform != Transform3D.Identity)
{
Matrix3D m = transform.Value;
m.MultiplyPoint(ref rayOrigin);
m.MultiplyVector(ref rayDirection);
PrependInverseTransform(m, ref viewMatrix);
}
RayHitTestParameters rayParameters = new RayHitTestParameters(rayOrigin, rayDirection);
//
// Compute HitTestProjectionMatrix
//
Matrix3D projectionMatrix = GetProjectionMatrix(aspectRatio, zn, zf);
// The projectionMatrix takes camera-space 3D points into normalized clip
// space.
// The viewportMatrix will take normalized clip space into
// viewport coordinates, with an additional 2D translation
// to put the ray at the rayOrigin.
Matrix3D viewportMatrix = new Matrix3D();
viewportMatrix.TranslatePrepend(new Vector3D(-p.X, viewSize.Height - p.Y, 0));
viewportMatrix.ScalePrepend(new Vector3D(viewSize.Width / 2, -viewSize.Height / 2, 1));
viewportMatrix.TranslatePrepend(new Vector3D(1, 1, 0));
// `First world-to-camera, then camera's projection, then normalized clip space to viewport.
rayParameters.HitTestProjectionMatrix =
viewMatrix *
projectionMatrix *
viewportMatrix;
//
// Perspective camera doesn't allow negative NearPlanes, so there's
// not much point in adjusting the ray origin. Hence, the
// distanceAdjustment remains 0.
//
distanceAdjustment = 0.0;
return(rayParameters);
}
internal abstract void RayHitTestCore(RayHitTestParameters rayParams);
/// <summary>
/// This overload is the same as the previous, but if the camera is looking along the plane/cylinder wall, then the output will be
/// constrained to a line/circle
/// NOTE: Sphere and circle will never be constrained, the lesser overload will be used instead
/// </summary>
public Point3D? CastRay(RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay, PerspectiveCamera camera, Viewport3D viewport)
{
if (_shape == ShapeType.None)
{
return null;
}
else if (_shape == ShapeType.Sphere || _shape == ShapeType.Circle || _shape == ShapeType.Circles)
{
return CastRay(mouseDownClickRay, mouseDownCenterRay, currentClickRay);
}
#region Get dot product
//NOTE: _camera.LookDirection and _camera.UpDirection are really screwed up (I think that the trackball messed them up), so fire a ray instead
// I'm not using the mouse click point, because that can change as they drag, and the inconsistency would be jarring
RayHitTestParameters cameraLook = UtilityWPF.RayFromViewportPoint(camera, viewport, new Point(viewport.ActualWidth / 2d, viewport.ActualHeight / 2d));
double dot = 0;
double[] dots = null;
Vector3D cameraLookUnit = cameraLook.Direction.ToUnit();
switch (_shape)
{
case ShapeType.Plane:
dot = Vector3D.DotProduct(_plane.NormalUnit, cameraLookUnit); // the dot is against the normal
break;
case ShapeType.Line:
case ShapeType.Cylinder:
//NOTE: They cylinder only limits movement if they are looking along the line.
dot = Vector3D.DotProduct(_direction.ToUnit(), cameraLookUnit); // the dot is along the drag line
break;
case ShapeType.Lines:
case ShapeType.LinesCircles: // I don't care about the dot product for the circles, they aren't limited
dots = _lines.Select(o => Vector3D.DotProduct(o.Direction.ToUnit(), cameraLookUnit)).ToArray();
break;
default:
throw new ApplicationException("finish this");
}
#endregion
Point3D? retVal = null;
switch (_shape)
{
case ShapeType.Line:
#region Line
if (Math.Abs(dot) > _constrainMaxDotProduct)
{
retVal = null;
}
else
{
double dummy1;
retVal = CastRay_Line(out dummy1, _point, _direction, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
}
#endregion
break;
case ShapeType.Lines:
case ShapeType.Circles:
case ShapeType.LinesCircles:
#region Lines/Circles
//NOTE: These have to look at _shape instead of null checks, because the values may be non null from a previous use
List<RayHitTestParameters> usableLines = new List<RayHitTestParameters>();
if (_shape == ShapeType.Lines || _shape == ShapeType.LinesCircles)
{
for (int cntr = 0; cntr < _lines.Length; cntr++)
{
if (Math.Abs(dots[cntr]) <= _constrainMaxDotProduct)
{
usableLines.Add(_lines[cntr]);
}
}
}
CircleDefinition[] usableCircles = null;
if (_shape == ShapeType.Circles || _shape == ShapeType.LinesCircles)
{
usableCircles = _circles; // all circles are always used
}
retVal = CastRay_LinesCircles(usableLines, usableCircles, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
#endregion
break;
case ShapeType.Plane:
#region Plane
if (Math.Abs(dot) < 1d - _constrainMaxDotProduct)
{
retVal = CastRay_PlaneLimited(_plane, mouseDownClickRay, mouseDownCenterRay, currentClickRay, cameraLook);
}
else
{
retVal = CastRay_Plane(_plane, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
}
#endregion
break;
case ShapeType.Cylinder:
#region Cylinder
if (Math.Abs(dot) > _constrainMaxDotProduct)
{
// Constrain to a circle
Vector3D circleVector1 = Math3D.GetArbitraryOrhonganal(_direction);
Vector3D circleVector2 = Vector3D.CrossProduct(circleVector1, _direction);
Triangle plane = new Triangle(_point, _point + circleVector1, _point + circleVector2);
double dummy1;
retVal = CastRay_Circle(out dummy1, plane, _point, _radius, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
}
else
{
retVal = CastRay_Cylinder(_point, _direction, _radius, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
}
#endregion
break;
case ShapeType.Mesh:
throw new ApplicationException("finish this");
case ShapeType.None:
retVal = null;
break;
default:
throw new ApplicationException("Unknown ShapeType: " + _shape.ToString());
}
return retVal;
}
/// <summary>
/// Static helper used by ModelVisual3D and Viewport3DVisual to hit test
/// against their children collections.
/// </summary>
internal static HitTestResultBehavior HitTestChildren(
HitTestFilterCallback filterCallback,
RayHitTestParameters rayParams,
IVisual3DContainer container)
{
if (container != null)
{
int childrenCount = container.GetChildrenCount();
for (int i = childrenCount - 1; i >= 0; i--)
{
Visual3D child = container.GetChild(i);
// Visuall3D.RayHitTest does not apply the Visual3D's Transform. We need to
// transform into the content's space before hit testing.
Transform3D transform = child.Transform;
rayParams.PushVisualTransform(transform);
// Perform the hit-test against the child.
HitTestResultBehavior result = child.RayHitTest(filterCallback, rayParams);
rayParams.PopTransform(transform);
if (result == HitTestResultBehavior.Stop)
{
return HitTestResultBehavior.Stop;
}
}
}
return HitTestResultBehavior.Continue;
}
private static Point3D? CastRay_Line(out double clickDistanceSquared, Point3D point, Vector3D direction, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
// This is the offset along the drag line from the center to mouse down click
Vector3D offset;
Point3D? point1, point2, point3, point4;
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, point, direction, mouseDownClickRay.Origin, mouseDownClickRay.Direction) &&
Math3D.GetClosestPoints_Line_Line(out point3, out point4, point, direction, mouseDownCenterRay.Origin, mouseDownCenterRay.Direction))
{
offset = point3.Value - point1.Value; // clickpoint on drag line minus centerpoint on drag line
}
else
{
// The click ray is parallel to the drag axis. This should be extremely rare
offset = new Vector3D(0, 0, 0);
}
// Now that the offset is known, project the current click ray onto the drag line
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, point, direction, currentClickRay.Origin, currentClickRay.Direction))
{
clickDistanceSquared = (point2.Value - point1.Value).LengthSquared;
return point1.Value + offset;
}
else
{
clickDistanceSquared = 0;
return null;
}
}
internal override RayHitTestParameters RayFromViewportPoint(Point p, Size viewSize, Rect3D boundingRect, out double distanceAdjustment)
{
//
// Compute rayParameters
//
// Find the point on the projection plane in post-projective space where
// the viewport maps to a 2x2 square from (-1,1)-(1,-1).
Point np = M3DUtil.GetNormalizedPoint(p, viewSize);
//
// So (conceptually) the user clicked on the point (np.X,
// np.Y, 0) in post-projection clipping space and the ray
// extends in the direction (0, 0, 1) because our ray
// after projection looks down the positive z axis. We
// need to convert this ray and direction back to world
// space.
Matrix3D worldToCamera = GetViewMatrix() * ProjectionMatrix;
Matrix3D cameraToWorld = worldToCamera;
if (!cameraToWorld.HasInverse)
{
//
// NTRAID#Longhorn-1180933-2004/07/30-danwo - Need to handle singular matrix cameras
throw new NotSupportedException(SR.Get(SRID.HitTest_Singular));
}
cameraToWorld.Invert();
Point4D origin4D = new Point4D(np.X,np.Y,0,1) * cameraToWorld;
Point3D origin = new Point3D( origin4D.X/origin4D.W,
origin4D.Y/origin4D.W,
origin4D.Z/origin4D.W );
// To transform the direction we use the Jacobian of
// cameraToWorld at the point np.X,np.Y,0 that we just
// transformed.
//
// The Jacobian of the homogeneous matrix M is a 3x3 matrix.
//
// Let x be the point we are computing the Jacobian at, and y be the
// result of transforming x by M, i.e.
// (wy w) = (x 1) M
// Where (wy w) is the homogeneous point representing y with w as its homogeneous coordinate
// And (x 1) is the homogeneous point representing x with 1 as its homogeneous coordinate
//
// Then the i,j component of the Jacobian (at x) is
// (M_ij - M_i4 y_j) / w
//
// Since we're only concerned with the direction of the
// transformed vector and not its magnitude, we can scale
// this matrix by a POSITIVE factor. The computation
// below computes the Jacobian scaled by 1/w and then
// after we normalize the final vector we flip it around
// if w is negative.
//
// To transform a vector we just right multiply it by this Jacobian matrix.
//
// Compute the Jacobian at np.X,np.Y,0 ignoring the constant factor of w.
// Here's the pattern
//
// double Jij = cameraToWorld.Mij - cameraToWorld.Mi4 * origin.j
//
// but we only need J31,J32,&J33 because we're only
// transforming the vector 0,0,1
double J31 = cameraToWorld.M31 - cameraToWorld.M34 * origin.X;
double J32 = cameraToWorld.M32 - cameraToWorld.M34 * origin.Y;
double J33 = cameraToWorld.M33 - cameraToWorld.M34 * origin.Z;
// Then multiply that matrix by (0, 0, 1) which is
// the direction of the ray in post-projection space.
Vector3D direction = new Vector3D( J31, J32, J33 );
direction.Normalize();
// We multiplied by the Jacobian times W, so we need to
// account for whether that flipped our result or not.
if (origin4D.W < 0)
{
direction = -direction;
}
RayHitTestParameters rayParameters = new RayHitTestParameters(origin, direction);
//
// Compute HitTestProjectionMatrix
//
// The viewportMatrix will take normalized clip space into
// viewport coordinates, with an additional 2D translation
// to put the ray at the origin.
Matrix3D viewportMatrix = new Matrix3D();
viewportMatrix.TranslatePrepend(new Vector3D(-p.X,viewSize.Height-p.Y,0));
viewportMatrix.ScalePrepend(new Vector3D(viewSize.Width/2,-viewSize.Height/2,1));
viewportMatrix.TranslatePrepend(new Vector3D(1,1,0));
// `First world-to-camera, then camera's projection, then normalized clip space to viewport.
rayParameters.HitTestProjectionMatrix =
worldToCamera *
viewportMatrix;
//
// MatrixCamera does not allow for Near/Far plane adjustment, so
// the distanceAdjustment remains 0.
//
distanceAdjustment = 0.0;
return rayParameters;
}
private static Point3D? CastRay_Circle(out double clickDistanceSquared, ITriangle plane, Point3D center, double radius, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
clickDistanceSquared = 0d; // this will get overwritten, but without setting it globally, the compiler will complain
// Get points on the circle
Point3D? mouseDownClickPoint = null;
Point3D? mouseDownCenterPoint = null;
Point3D? currentClickPoint = null;
Point3D[] nearestCirclePoints, nearestLinePoints;
if (Math3D.GetClosestPoints_Circle_Line(out nearestCirclePoints, out nearestLinePoints, plane, center, radius, currentClickRay.Origin, currentClickRay.Direction, Math3D.RayCastReturn.ClosestToRay))
{
clickDistanceSquared = (nearestLinePoints[0] - nearestCirclePoints[0]).LengthSquared;
currentClickPoint = nearestCirclePoints[0];
if (Math3D.GetClosestPoints_Circle_Line(out nearestCirclePoints, out nearestLinePoints, plane, center, radius, mouseDownClickRay.Origin, mouseDownClickRay.Direction, Math3D.RayCastReturn.ClosestToRay))
{
mouseDownClickPoint = nearestCirclePoints[0];
if (Math3D.GetClosestPoints_Circle_Line(out nearestCirclePoints, out nearestLinePoints, plane, center, radius, mouseDownCenterRay.Origin, mouseDownCenterRay.Direction, Math3D.RayCastReturn.ClosestToRay))
{
mouseDownCenterPoint = nearestCirclePoints[0];
}
}
}
if (mouseDownCenterPoint == null || mouseDownClickPoint == null || currentClickPoint == null)
{
clickDistanceSquared = 0d;
return currentClickPoint; // it doesn't matter if this one is null or not, the offset can't be determined, so just return the raw click value
}
// Get the offset
Vector3D mouseDownClickLine = mouseDownClickPoint.Value - center;
Vector3D mouseDownCenterLine = mouseDownCenterPoint.Value - center;
Quaternion offset = Math3D.GetRotation(mouseDownClickLine, mouseDownCenterLine);
// Convert to local, and rotate by offset
Vector3D currentClickLine = currentClickPoint.Value - center;
currentClickLine = new RotateTransform3D(new QuaternionRotation3D(offset)).Transform(currentClickLine);
// Now convert back to world coords
return center + currentClickLine;
}
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
//
// Processes a ray-triangle intersection to see if it's a valid hit. Unnecessary faces
// have already been culled by the ray-triange intersection routines.
//
// Shares some code with ValidateLineHit
//
private void ValidateRayHit(
RayHitTestParameters rayParams,
ref Point3D origin,
ref Vector3D direction,
double hitTime,
int i0,
int i1,
int i2,
ref Point barycentric
)
{
if (hitTime > 0)
{
Matrix3D worldTransformMatrix = rayParams.HasWorldTransformMatrix ? rayParams.WorldTransformMatrix : Matrix3D.Identity;
Point3D pointHit = origin + hitTime * direction;
Point3D worldPointHit = pointHit;
worldTransformMatrix.MultiplyPoint(ref worldPointHit);
// If we have a HitTestProjectionMatrix than this hit test originated
// at a Viewport3DVisual.
if (rayParams.HasHitTestProjectionMatrix)
{
// To test if we are in front of the far clipping plane what we
// do conceptually is project our hit point in world space into
// homogenous space and verify that it is on the correct side of
// the Z=1 plane.
//
// To save some cycles we only bother computing Z and W of the
// projected point and use a simple Z/W > 1 test to see if we
// are past the far plane.
//
// NOTE: HitTestProjectionMatrix is not just the camera matrices.
// It has an additional translation to move the ray to the
// origin. This extra translation does not effect this test.
Matrix3D m = rayParams.HitTestProjectionMatrix;
// We directly substitute 1 for p.W below:
double pz = worldPointHit.X * m.M13 + worldPointHit.Y * m.M23 + worldPointHit.Z * m.M33 + m.OffsetZ;
double pw = worldPointHit.X * m.M14 + worldPointHit.Y * m.M24 + worldPointHit.Z * m.M34 + m.M44;
// Early exit if pz/pw > 1. The negated logic is to reject NaNs.
if (!(pz / pw <= 1))
{
return;
}
Debug.Assert(!double.IsInfinity(pz / pw) && !double.IsNaN(pz / pw),
"Expected near/far tests to cull -Inf/+Inf and NaN.");
}
double dist = (worldPointHit - rayParams.Origin).Length;
Debug.Assert(dist > 0, "Distance is negative: " + dist);
if (rayParams.HasModelTransformMatrix)
{
rayParams.ModelTransformMatrix.MultiplyPoint(ref pointHit);
}
rayParams.ReportResult(this, pointHit, dist, i0, i1, i2, barycentric);
}
}
private static Point3D? CastRay_Sphere(Point3D center, double radius, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
// Get points on the sphere
Point3D[] nearestSpherePoints, nearestLinePoints;
Math3D.GetClosestPoints_Sphere_Line(out nearestSpherePoints, out nearestLinePoints, center, radius, currentClickRay.Origin, currentClickRay.Direction, Math3D.RayCastReturn.ClosestToRay);
Point3D currentClickPoint = nearestSpherePoints[0];
//TODO: The rest of this method is flawed, it should be fixed (I don't think it's as simplistic as I'm making it - or there is just a flaw in the math)
// Actually, I think the flaw is taking it to world coords, rotating, and putting back?
return currentClickPoint;
//Math3D.GetClosestPointsBetweenLineSphere(out nearestSpherePoints, out nearestLinePoints, center, radius, mouseDownClickRay.Origin, mouseDownClickRay.Direction, Math3D.RayCastReturn.ClosestToRay);
//Point3D mouseDownClickPoint = nearestSpherePoints[0];
//Math3D.GetClosestPointsBetweenLineSphere(out nearestSpherePoints, out nearestLinePoints, center, radius, mouseDownCenterRay.Origin, mouseDownCenterRay.Direction, Math3D.RayCastReturn.ClosestToRay);
//Point3D mouseDownCenterPoint = nearestSpherePoints[0];
//// Get the offset from mouse down click to center
//Vector3D mouseDownClickLine = mouseDownClickPoint - center;
//Vector3D mouseDownCenterLine = mouseDownCenterPoint - center;
//Quaternion offset = Math3D.GetRotation(mouseDownClickLine, mouseDownCenterLine);
//// Convert to local coords, rotate
//Vector3D currentClickLine = currentClickPoint - center;
//currentClickLine = new RotateTransform3D(new QuaternionRotation3D(offset)).Transform(currentClickLine);
//// Now convert back to world coords
//return center + currentClickLine;
}
internal override RayHitTestParameters RayFromViewportPoint(Point p, Size viewSize, Rect3D boundingRect, out double distanceAdjustment)
{
// The camera may be animating. Take a snapshot of the current value
// and get the property values we need. (Window OS #992662)
Point3D position = Position;
Vector3D lookDirection = LookDirection;
Vector3D upDirection = UpDirection;
double zn = NearPlaneDistance;
double zf = FarPlaneDistance;
double width = Width;
//
// Compute rayParameters
//
// Find the point on the projection plane in post-projective space where
// the viewport maps to a 2x2 square from (-1,1)-(1,-1).
Point np = M3DUtil.GetNormalizedPoint(p, viewSize);
double aspectRatio = M3DUtil.GetAspectRatio(viewSize);
double w = width;
double h = w / aspectRatio;
// Direction is always perpendicular to the viewing surface.
Vector3D direction = new Vector3D(0, 0, -1);
// Apply the inverse of the view matrix to our ray.
Matrix3D viewMatrix = CreateViewMatrix(Transform, ref position, ref lookDirection, ref upDirection);
Matrix3D invView = viewMatrix;
invView.Invert();
// We construct our ray such that the origin resides on the near
// plane. If our near plane is too far from our the bounding box
// of our scene then the results will be inaccurate. (e.g.,
// OrthographicCameras permit negative near planes, so the near
// plane could be at -Inf.)
//
// However, it is permissable to move the near plane nearer to
// the scene bounds without changing what the ray intersects.
// If the near plane is sufficiently far from the scene bounds
// we make this adjustment below to increase precision.
Rect3D transformedBoundingBox =
M3DUtil.ComputeTransformedAxisAlignedBoundingBox(
ref boundingRect,
ref viewMatrix);
// DANGER: The NearPlaneDistance property is specified as a
// distance from the camera position along the
// LookDirection with (Near < Far).
//
// However, when we transform our scene bounds so that
// the camera is aligned with the negative Z-axis the
// relationship inverts (Near > Far) as illustrated
// below:
//
// NearPlane Y FarPlane
// | ^ |
// | | |
// | | (rect.Z + rect.SizeZ) |
// | | o____ |
// | | | | |
// | | | | |
// | | ____o |
// | | (rect.Z) |
// | Camera -> |
// +Z <----------+----------------------------> -Z
// | 0 |
//
// It is surprising, but its the "far" side of the
// transformed scene bounds that determines the near
// plane distance.
double zn2 = -AddEpsilon(transformedBoundingBox.Z + transformedBoundingBox.SizeZ);
if (zn2 > zn)
{
//
// Our near plane is far from our children. Construct a new
// near plane that's closer. Note that this will modify our
// distance computations, so we have to be sure to adjust our
// distances appropriately.
//
distanceAdjustment = zn2 - zn;
zn = zn2;
}
else
{
//
// Our near plane is either close to or in front of our
// children, so let's keep it -- no distance adjustment needed.
//
distanceAdjustment = 0.0;
}
// Our origin is the point normalized to the front of our viewing volume.
// To find our origin's x/y we just need to scale the normalize point by our
// width/height. In camera space we are looking down the negative Z axis
// so we just set Z to be -zn which puts us on the projection plane
// (Windows OS #1005064).
Point3D origin = new Point3D(np.X * (w / 2), np.Y * (h / 2), -zn);
invView.MultiplyPoint(ref origin);
invView.MultiplyVector(ref direction);
RayHitTestParameters rayParameters = new RayHitTestParameters(origin, direction);
//
// Compute HitTestProjectionMatrix
//
Matrix3D projectionMatrix = GetProjectionMatrix(aspectRatio, zn, zf);
// The projectionMatrix takes camera-space 3D points into normalized clip
// space.
// The viewportMatrix will take normalized clip space into
// viewport coordinates, with an additional 2D translation
// to put the ray at the origin.
Matrix3D viewportMatrix = new Matrix3D();
viewportMatrix.TranslatePrepend(new Vector3D(-p.X, viewSize.Height - p.Y, 0));
viewportMatrix.ScalePrepend(new Vector3D(viewSize.Width / 2, -viewSize.Height / 2, 1));
viewportMatrix.TranslatePrepend(new Vector3D(1, 1, 0));
// `First world-to-camera, then camera's projection, then normalized clip space to viewport.
rayParameters.HitTestProjectionMatrix =
viewMatrix *
projectionMatrix *
viewportMatrix;
return(rayParameters);
}
internal HitTestResultBehavior RayHitTest(
HitTestFilterCallback filterCallback,
RayHitTestParameters rayParams)
{
if (DoesRayHitSubgraphBounds(rayParams))
{
//
// Determine if there is a special filter behavior defined for this
// Visual.
//
HitTestFilterBehavior behavior = HitTestFilterBehavior.Continue;
if (filterCallback != null)
{
behavior = filterCallback(this);
if (HTFBInterpreter.SkipSubgraph(behavior)) return HitTestResultBehavior.Continue;
if (HTFBInterpreter.Stop(behavior)) return HitTestResultBehavior.Stop;
}
//
// Hit test against the children.
//
if (HTFBInterpreter.IncludeChildren(behavior))
{
HitTestResultBehavior result = HitTestChildren(filterCallback, rayParams);
if (result == HitTestResultBehavior.Stop) return HitTestResultBehavior.Stop;
}
//
// Hit test against the content of this Visual.
//
if (HTFBInterpreter.DoHitTest(behavior))
{
RayHitTestInternal(filterCallback, rayParams);
}
}
return HitTestResultBehavior.Continue;
}
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
#region Public Properties
internal override void RayHitTestCore(RayHitTestParameters rayParams)
{
// Lights are considered to be part of the model graph, but they
// have no geometry and therefore can not be hit tested.
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
internal bool DoesRayHitSubgraphBounds(RayHitTestParameters rayParams)
{
Point3D origin;
Vector3D direction;
rayParams.GetLocalLine(out origin, out direction);
Rect3D bboxSubgraph = VisualDescendantBounds;
return LineUtil.ComputeLineBoxIntersection(ref origin, ref direction, ref bboxSubgraph, rayParams.IsRay);
}
private static Point3D? CastRay_LinesCircles(IEnumerable<RayHitTestParameters> lines, IEnumerable<CircleDefinition> circles, RayHitTestParameters ray)
{
Point3D? retVal = null;
double distance = double.MaxValue;
if (lines != null)
{
// Cast onto each line, and return the point that's closest to the ray's origin
foreach (RayHitTestParameters line in lines)
{
Point3D? point1, point2;
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, line.Origin, line.Direction, ray.Origin, ray.Direction))
{
double localDistance = (point2.Value - point1.Value).LengthSquared;
if (retVal == null || localDistance < distance)
{
retVal = point1.Value;
distance = localDistance;
}
}
}
}
if (circles != null)
{
// Cast onto each circle, and return the point that's closest to the ray's origin
foreach (CircleDefinition circle in circles)
{
Point3D[] points1, points2;
if (Math3D.GetClosestPoints_Circle_Line(out points1, out points2, circle.Plane, circle.Center, circle.Radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay))
{
double localDistance = (points2[0] - points1[0]).LengthSquared;
if (retVal == null || localDistance < distance)
{
retVal = points1[0];
distance = localDistance;
}
}
}
}
return retVal;
}
internal HitTestResultBehavior HitTestChildren(
HitTestFilterCallback filterCallback,
RayHitTestParameters rayParams)
{
return HitTestChildren(filterCallback, rayParams, this);
}
public void GetShape_Line(out RayHitTestParameters line)
{
if (_shape != ShapeType.Line)
{
throw new InvalidOperationException("This class isn't set up for a line: " + _shape.ToString());
}
line = new RayHitTestParameters(_point, _direction);
}
internal void RayHitTestInternal(
HitTestFilterCallback filterCallback,
RayHitTestParameters rayParams)
{
Model3D model = _visual3DModel;
if (model != null)
{
// If our Model3D hit test intersects anything we should return "this" Visual3D
// as the HitTestResult.VisualHit.
rayParams.CurrentVisual = this;
model.RayHitTest(rayParams);
}
}
private static Point3D? CastRay_LinesCircles(IEnumerable<RayHitTestParameters> lines, IEnumerable<CircleDefinition> circles, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
Point3D? retVal = null;
double distance = double.MaxValue;
if (lines != null)
{
// Cast onto each line, and return the point that's closest to the ray's origin
foreach (RayHitTestParameters line in lines)
{
double localDistance;
Point3D? localPoint = CastRay_Line(out localDistance, line.Origin, line.Direction, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
if (localPoint != null)
{
if (retVal == null || localDistance < distance)
{
retVal = localPoint.Value;
distance = localDistance;
}
}
}
}
if (circles != null)
{
// Cast onto each circle, and return the point that's closest to the ray's origin
foreach (CircleDefinition circle in circles)
{
double localDistance;
Point3D? localPoint = CastRay_Circle(out localDistance, circle.Plane, circle.Center, circle.Radius, mouseDownClickRay, mouseDownCenterRay, currentClickRay);
if (localPoint != null)
{
if (retVal == null || localDistance < distance)
{
retVal = localPoint.Value;
distance = localDistance;
}
}
}
}
return retVal;
}
internal abstract void RayHitTestCore(RayHitTestParameters rayParams, FaceType hitTestableFaces);
public void GetShape_Cylinder(out RayHitTestParameters axis, out double radius)
{
if (_shape != ShapeType.Cylinder)
{
throw new InvalidOperationException("This class isn't set up for a cylinder: " + _shape.ToString());
}
axis = new RayHitTestParameters(_point, _direction);
radius = _radius;
}
//
// Hits the ray against the mesh
//
internal override void RayHitTestCore(
RayHitTestParameters rayParams,
FaceType hitTestableFaces)
{
Debug.Assert(hitTestableFaces != FaceType.None,
"Caller should make sure we're trying to hit something");
Point3DCollection positions = Positions;
if (positions == null)
{
return;
}
Point3D origin;
Vector3D direction;
rayParams.GetLocalLine(out origin, out direction);
Int32Collection indices = TriangleIndices;
// In the line case, we want to hit test all faces because we don't
// have a direction. This may differ from what faces we want to
// accept.
FaceType facesToHit;
if (rayParams.IsRay)
{
facesToHit = hitTestableFaces;
}
else
{
facesToHit = FaceType.Front | FaceType.Back;
}
//
// This code duplication is unfortunate but necessary. Breaking it down into methods
// further significantly impacts performance. About 5% improvement could be made
// by unrolling this code below even more.
//
// If futher perf investigation is done with this code, be sure to test NGEN assemblies only
// as JIT produces different, faster code than NGEN.
//
if (indices == null || indices.Count == 0)
{
FrugalStructList<Point3D> ps = positions._collection;
int count = ps.Count - (ps.Count % 3);
for (int i = count - 1; i >= 2; i -= 3)
{
int i0 = i - 2;
int i1 = i - 1;
int i2 = i;
Point3D v0 = ps[i0];
Point3D v1 = ps[i1];
Point3D v2 = ps[i2];
double hitTime;
Point barycentric;
// The line hit test is equivalent to a double sided
// triangle hit because it doesn't cull triangles based
// on winding
if (LineUtil.ComputeLineTriangleIntersection(
facesToHit,
ref origin,
ref direction,
ref v0,
ref v1,
ref v2,
out barycentric,
out hitTime
)
)
{
if (rayParams.IsRay)
{
ValidateRayHit(
rayParams,
ref origin,
ref direction,
hitTime,
i0,
i1,
i2,
ref barycentric
);
}
else
{
ValidateLineHit(
rayParams,
hitTestableFaces,
i0,
i1,
i2,
ref v0,
ref v1,
ref v2,
ref barycentric
);
}
}
}
}
else // indexed mesh
{
FrugalStructList<Point3D> ps = positions._collection;
FrugalStructList<int> idcs = indices._collection;
int count = idcs.Count;
int limit = ps.Count;
for (int i = 2; i < count; i += 3)
{
int i0 = idcs[i - 2];
int i1 = idcs[i - 1];
int i2 = idcs[i];
// Quit if we encounter an index out of range.
// This is okay because the triangles we ignore are not rendered.
// (see: CMilMeshGeometry3DDuce::Realize)
if ((0 > i0 || i0 >= limit) ||
(0 > i1 || i1 >= limit) ||
(0 > i2 || i2 >= limit))
{
break;
}
Point3D v0 = ps[i0];
Point3D v1 = ps[i1];
Point3D v2 = ps[i2];
double hitTime;
Point barycentric;
if (LineUtil.ComputeLineTriangleIntersection(
facesToHit,
ref origin,
ref direction,
ref v0,
ref v1,
ref v2,
out barycentric,
out hitTime
)
)
{
if (rayParams.IsRay)
{
ValidateRayHit(
rayParams,
ref origin,
ref direction,
hitTime,
i0,
i1,
i2,
ref barycentric
);
}
else
{
ValidateLineHit(
rayParams,
hitTestableFaces,
i0,
i1,
i2,
ref v0,
ref v1,
ref v2,
ref barycentric
);
}
}
}
}
}
public void SetShape_Line(RayHitTestParameters line)
{
_shape = ShapeType.Line;
_point = line.Origin;
_direction = line.Direction;
}
//
// Processes a ray-line intersection to see if it's a valid hit.
//
// Shares some code with ValidateRayHit
//
private void ValidateLineHit(
RayHitTestParameters rayParams,
FaceType facesToHit,
int i0,
int i1,
int i2,
ref Point3D v0,
ref Point3D v1,
ref Point3D v2,
ref Point barycentric
)
{
Matrix3D worldTransformMatrix = rayParams.HasWorldTransformMatrix ? rayParams.WorldTransformMatrix : Matrix3D.Identity;
// OK, we have an intersection with the LINE but that could be wrong on three
// accounts:
// 1. We could have hit the line on the wrong side of the ray's origin.
// 2. We may need to cull the intersection if it's beyond the far clipping
// plane (only if the hit test originated from a Viewport3DVisual.)
// 3. We could have hit a back-facing triangle
// We will transform the hit point back into world space to check these
// things & compute the correct distance from the origin to the hit point.
// Hit point in model space
Point3D pointHit = M3DUtil.Interpolate(ref v0, ref v1, ref v2, ref barycentric);
Point3D worldPointHit = pointHit;
worldTransformMatrix.MultiplyPoint(ref worldPointHit);
// Vector from origin to hit point
Vector3D hitVector = worldPointHit - rayParams.Origin;
Vector3D originalDirection = rayParams.Direction;
double rayDistanceUnnormalized = Vector3D.DotProduct(originalDirection, hitVector);
if (rayDistanceUnnormalized > 0)
{
// If we have a HitTestProjectionMatrix than this hit test originated
// at a Viewport3DVisual.
if (rayParams.HasHitTestProjectionMatrix)
{
// To test if we are in front of the far clipping plane what we
// do conceptually is project our hit point in world space into
// homogenous space and verify that it is on the correct side of
// the Z=1 plane.
//
// To save some cycles we only bother computing Z and W of the
// projected point and use a simple Z/W > 1 test to see if we
// are past the far plane.
//
// NOTE: HitTestProjectionMatrix is not just the camera matrices.
// It has an additional translation to move the ray to the
// origin. This extra translation does not effect this test.
Matrix3D m = rayParams.HitTestProjectionMatrix;
// We directly substitute 1 for p.W below:
double pz = worldPointHit.X * m.M13 + worldPointHit.Y * m.M23 + worldPointHit.Z * m.M33 + m.OffsetZ;
double pw = worldPointHit.X * m.M14 + worldPointHit.Y * m.M24 + worldPointHit.Z * m.M34 + m.M44;
// Early exit if pz/pw > 1. The negated logic is to reject NaNs.
if (!(pz / pw <= 1))
{
return;
}
Debug.Assert(!double.IsInfinity(pz / pw) && !double.IsNaN(pz / pw),
"Expected near/far tests to cull -Inf/+Inf and NaN.");
}
Point3D a = v0, b = v1, c = v2;
worldTransformMatrix.MultiplyPoint(ref a);
worldTransformMatrix.MultiplyPoint(ref b);
worldTransformMatrix.MultiplyPoint(ref c);
Vector3D normal = Vector3D.CrossProduct(b - a, c - a);
double cullSign = -Vector3D.DotProduct(normal, hitVector);
double det = worldTransformMatrix.Determinant;
bool frontFace = (cullSign > 0) == (det >= 0);
if (((facesToHit & FaceType.Front) == FaceType.Front && frontFace) || ((facesToHit & FaceType.Back) == FaceType.Back && !frontFace))
{
double dist = hitVector.Length;
if (rayParams.HasModelTransformMatrix)
{
rayParams.ModelTransformMatrix.MultiplyPoint(ref pointHit);
}
rayParams.ReportResult(this, pointHit, dist, i0, i1, i2, barycentric);
}
}
}
public void SetShape_Cylinder(RayHitTestParameters axis, double radius)
{
_shape = ShapeType.Cylinder;
_point = axis.Origin;
_direction = axis.Direction;
_radius = radius;
}