// http://www.geometrictools.com/Documentation/DistancePointLine.pdf
public static float DistanceToLine_3(SSRay ray, Vector3 point)
{
float t0 = Vector3.Dot(ray.dir, (point - ray.pos)) / Vector3.Dot(ray.dir, ray.dir);
float distance = (point - (ray.pos + (t0 * ray.dir))).Length;
return(distance);
}
public override bool Intersect(ref SSRay worldSpaceRay)
{
// transform the ray into object space
SSRay localRay = worldSpaceRay.Transformed(this.worldMat.Inverted());
float distanceToSphereOrigin = OpenTKHelper.DistanceToLine(localRay,Vector3.Zero);
bool result = distanceToSphereOrigin <= this.radius;
#if false
Console.WriteLine("_____________________________");
Console.WriteLine("sphere intersect test {0} vs radius {1}",distanceToSphereOrigin,radius);
Console.WriteLine("worldray {0}",worldSpaceRay);
Console.WriteLine("localray {0}",localRay);
Console.WriteLine("objectPos {0}",this.Pos);
if (result) {
Console.WriteLine(" ----> hit <-----");
Console.WriteLine("----------------------------");
} else {
Console.WriteLine(" miss");
Console.WriteLine("----------------------------");
}
#endif
return result;
}
public override bool PreciseIntersect(ref SSRay worldSpaceRay, ref float distanceAlongRay)
{
SSRay localRay = worldSpaceRay.Transformed (this.worldMat.Inverted ());
SSAbstractMesh mesh = this._mesh;
bool hit = false;
float localNearestContact = float.MaxValue;
if (mesh == null) {
return true; // no mesh to test
} else {
// precise meshIntersect
bool global_hit = mesh.traverseTriangles ((state, V1, V2, V3) => {
float contact;
if (OpenTKHelper.TriangleRayIntersectionTest (V1, V2, V3, localRay.pos, localRay.dir, out contact)) {
hit = true;
localNearestContact = Math.Min (localNearestContact, contact);
Console.WriteLine ("Triangle Hit @ {0} : Object {1}", contact, Name);
}
return false; // don't short circuit
});
if (hit) {
float worldSpaceContactDistance = -localNearestContact * this.Scale.LengthFast;
Console.WriteLine ("Nearest Triangle Hit @ {0} vs Sphere {1} : Object {2}", worldSpaceContactDistance, distanceAlongRay, Name);
distanceAlongRay = worldSpaceContactDistance;
}
return global_hit || hit;
}
}
public SSObject Intersect(ref SSRay worldSpaceRay)
{
SSObject nearestIntersection = null;
float nearestDistance = float.MinValue;
// distances get "smaller" as they move in camera direction for some reason (why?)
foreach (var obj in m_objects)
{
float distanceAlongRay;
if (obj.Intersect(ref worldSpaceRay, out distanceAlongRay))
{
// intersection must be in front of the camera ( < 0.0 )
if (distanceAlongRay < 0.0)
{
Console.WriteLine("intersect: [{0}] @distance: {1}", obj.Name, distanceAlongRay);
// then we want the nearest one (numerically biggest
if (distanceAlongRay > nearestDistance)
{
nearestDistance = distanceAlongRay;
nearestIntersection = obj;
}
}
}
}
return(nearestIntersection);
}
public SSObjectRay(SSRay ray) : base()
{
this.ray = ray;
this.Pos = ray.pos;
// the ray is in world-space, so we adjust our object pos, and then save the ray (so we have the world-space ray.dir)
// NOTE: technically the ray.pos is still the world-space pos...
}
public SSObjectRay(SSRay ray)
: base()
{
this.ray = ray;
this.Pos = ray.pos;
// the ray is in world-space, so we adjust our object pos, and then save the ray (so we have the world-space ray.dir)
// NOTE: technically the ray.pos is still the world-space pos...
}
public SSObjectRay(SSRay ray) : base()
{
this.ray = ray;
this.Pos = ray.pos;
this.renderState.alphaBlendingOn = false;
this.renderState.lighted = false;
// the ray is in world-space, so we adjust our object pos, and then save the ray (so we have the world-space ray.dir)
// NOTE: technically the ray.pos is still the world-space pos...
}
/// <summary>
/// Distance from a ray to a point at the closest spot. The ray is assumed to be infinite length.
/// </summary>
/// <param name="ray"></param>
/// <param name="point"></param>
/// <returns></returns>
public static float DistanceToLine(SSRay ray, Vector3 point)
{
// http://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line
Vector3 a = ray.pos;
Vector3 n = ray.dir;
Vector3 p = point;
return ((a-p) - Vector3.Dot((a-p),n) * n).Length;
}
public SSObjectRay(SSRay ray)
: base()
{
this.ray = ray;
this.Pos = ray.pos;
this.renderState.alphaBlendingOn = false;
this.renderState.lighted = false;
// the ray is in world-space, so we adjust our object pos, and then save the ray (so we have the world-space ray.dir)
// NOTE: technically the ray.pos is still the world-space pos...
}
/// <summary>
/// Distance from a ray to a point at the closest spot. The ray is assumed to be infinite length.
/// </summary>
/// <param name="ray"></param>
/// <param name="point"></param>
/// <returns></returns>
public static float DistanceToLine(SSRay ray, Vector3 point, out float distanceAlongRay)
{
// http://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line
Vector3 a = ray.pos;
Vector3 n = ray.dir;
Vector3 p = point;
var t = Vector3.Dot((a-p),n);
distanceAlongRay = -t;
return ((a-p) - t * n).Length;
}
/// <summary>
/// Distance from a ray to a point at the closest spot. The ray is assumed to be infinite length.
/// </summary>
/// <param name="ray"></param>
/// <param name="point"></param>
/// <returns></returns>
public static float DistanceToLine(SSRay ray, Vector3 point, out float distanceAlongRay)
{
// http://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line
Vector3 a = ray.pos;
Vector3 n = ray.dir;
Vector3 p = point;
distanceAlongRay = Vector3.Dot((a - p), n);
return(((a - p) - distanceAlongRay * n).Length);
}
// MouseToWorldRay
//
// This takes the view matricies, and a window-local mouse coordinate, and returns a ray in world space.
public static SSRay MouseToWorldRay(
Matrix4 projection,
Matrix4 view,
System.Drawing.Size viewport,
Vector2 mouse)
{
// these mouse.Z values are NOT scientific.
// Near plane needs to be < -1.5f or we have trouble selecting objects right in front of the camera. (why?)
Vector3 pos1 = UnProject(ref projection, view, viewport, new Vector3(mouse.X, mouse.Y, -1.5f)); // near
Vector3 pos2 = UnProject(ref projection, view, viewport, new Vector3(mouse.X, mouse.Y, 1.0f)); // far
return(SSRay.FromTwoPoints(pos1, pos2));
}
public virtual bool Intersect(ref SSRay worldSpaceRay, out float distanceAlongRay)
{
distanceAlongRay = 0.0f;
if (localBoundingSphereRadius > 0f)
{
var objBoundingSphere = worldBoundingSphere;
if (objBoundingSphere.IntersectsRay(ref worldSpaceRay, out distanceAlongRay))
{
return(PreciseIntersect(ref worldSpaceRay, ref distanceAlongRay));
}
}
distanceAlongRay = 0f;
return(false);
}
public override bool preciseIntersect(ref SSRay localRay, out float localRayContact)
{
localRayContact = float.PositiveInfinity;
foreach (var subset in geometrySubsets)
{
float contact;
if (subset.triangleMesh.preciseIntersect(ref localRay, out contact) &&
contact < localRayContact)
{
localRayContact = contact;
}
}
return(localRayContact < float.PositiveInfinity);
}
public virtual bool Intersect(ref SSRay worldSpaceRay, out float distanceAlongRay)
{
distanceAlongRay = 0.0f;
if (boundingSphere != null)
{
if (boundingSphere.Intersect(ref worldSpaceRay, out distanceAlongRay))
{
if (collisionShell != null)
{
return(collisionShell.Intersect(ref worldSpaceRay, out distanceAlongRay));
}
else
{
return(PreciseIntersect(ref worldSpaceRay, ref distanceAlongRay));
}
}
}
return(false);
}
// Ray to AABB (AxisAlignedBoundingBox)
// http://gamedev.stackexchange.com/questions/18436/most-efficient-aabb-vs-ray-collision-algorithms
public static bool intersectRayAABox2(SSRay ray, SSAABB box, ref float tnear, ref float tfar)
{
Vector3d T_1 = new Vector3d();
Vector3d T_2 = new Vector3d(); // vectors to hold the T-values for every direction
double t_near = double.MinValue; // maximums defined in float.h
double t_far = double.MaxValue;
for (int i = 0; i < 3; i++) //we test slabs in every direction
{
if (ray.dir[i] == 0) // ray parallel to planes in this direction
{
if ((ray.pos[i] < box.Min[i]) || (ray.pos[i] > box.Max[i]))
{
return(false); // parallel AND outside box : no intersection possible
}
}
else // ray not parallel to planes in this direction
{
T_1[i] = (box.Min[i] - ray.pos[i]) / ray.dir[i];
T_2[i] = (box.Max[i] - ray.pos[i]) / ray.dir[i];
if (T_1[i] > T_2[i]) // we want T_1 to hold values for intersection with near plane
{
var swp = T_2; // swap
T_1 = swp; T_2 = T_1;
}
if (T_1[i] > t_near)
{
t_near = T_1[i];
}
if (T_2[i] < t_far)
{
t_far = T_2[i];
}
if ((t_near > t_far) || (t_far < 0))
{
return(false);
}
}
}
tnear = (float)t_near; tfar = (float)t_far; // put return values in place
return(true); // if we made it here, there was an intersection - YAY
}
public override bool PreciseIntersect(ref SSRay worldSpaceRay, ref float distanceAlongWorldRay)
{
SSRay localRay = worldSpaceRay.Transformed (this.worldMat.Inverted ());
if (this.Mesh != null) {
float localNearestContact;
bool ret = this.Mesh.preciseIntersect(ref localRay, out localNearestContact);
if (ret) {
Vector3 localContactPt = localRay.pos + localNearestContact * localRay.dir;
Vector3 worldContactPt = Vector3.Transform(localContactPt, this.worldMat);
distanceAlongWorldRay = (worldContactPt - worldSpaceRay.pos).Length;
//Console.WriteLine ("Nearest Triangle Hit @ {0} vs Sphere {1} : Object {2}", worldSpaceContactDistance, distanceAlongRay, Name);
} else {
distanceAlongWorldRay = float.PositiveInfinity;
}
return ret;
} else {
distanceAlongWorldRay = float.PositiveInfinity;
return false;
}
}
} // fn
public static bool intersectRayAABox1(SSRay ray, SSAABB box, ref float tnear, ref float tfar)
{
// r.dir is unit direction vector of ray
Vector3 dirfrac = new Vector3();
float t;
dirfrac.X = 1.0f / ray.dir.X;
dirfrac.Y = 1.0f / ray.dir.Y;
dirfrac.Z = 1.0f / ray.dir.Z;
// lb is the corner of AABB with minimal coordinates - left bottom, rt is maximal corner
// r.org is origin of ray
float t1 = (box.Min.X - ray.pos.X) * dirfrac.X;
float t2 = (box.Max.X - ray.pos.X) * dirfrac.X;
float t3 = (box.Min.Y - ray.pos.Y) * dirfrac.Y;
float t4 = (box.Max.Y - ray.pos.Y) * dirfrac.Y;
float t5 = (box.Min.Z - ray.pos.Z) * dirfrac.Z;
float t6 = (box.Max.Z - ray.pos.Z) * dirfrac.Z;
float tmin = Math.Max(Math.Max(Math.Min(t1, t2), Math.Min(t3, t4)), Math.Min(t5, t6));
float tmax = Math.Min(Math.Min(Math.Max(t1, t2), Math.Max(t3, t4)), Math.Max(t5, t6));
// if tmax < 0, ray (line) is intersecting AABB, but whole AABB is behing us
if (tmax < 0)
{
t = tmax;
return(false);
}
// if tmin > tmax, ray doesn't intersect AABB
if (tmin > tmax)
{
t = tmax;
return(false);
}
t = tmin;
return(true);
}
/// <summary>
/// Whether the plane and a ray intersect and where
/// http://en.wikipedia.org/wiki/Line%E2%80%93plane_intersection
/// </summary>
public bool intersects(ref SSRay ray, out Vector3 intersectPt)
{
Vector3 n = this.normal;
var rayDirDotPlaneN = Vector3.Dot(ray.dir, n);
if (Math.Abs(rayDirDotPlaneN) < epsilon) {
// rayDirDotPlaneN == 0; ray and the plane are parallel
intersectPt = new Vector3 (float.NaN);
return false;
} else {
// plug parametric equation of a line into the plane normal equation
// solve (rayPos + rayDir * t - planeP0) dot planeN == 0
// rayDir dot planeN + (rayPos - planeP0) dot planeN == 0
Vector3 p0 = this.pickASurfacePoint();
float t = Vector3.Dot(p0 - ray.pos, n) / rayDirDotPlaneN;
if (t < -epsilon) {
// this means that the line-plane intersection is behind the ray origin (in the wrong
// direction). in the context of a ray this means no intersection
intersectPt = new Vector3 (float.NaN);
return false;
}
intersectPt = ray.pos + ray.dir * t;
return true;
}
}
public static float DistanceToLine_2(SSRay ray, Vector3 point)
{
return Vector3.Cross(ray.dir, point - ray.pos).Length;
}
public virtual bool PreciseIntersect(ref SSRay worldSpaceRay, ref float distanceAlongRay)
{
return(true);
}
public override bool preciseIntersect(ref SSRay localRay, out float localRayContact)
{
localRayContact = float.PositiveInfinity;
foreach (var subset in geometrySubsets) {
float contact;
if (subset.triangleMesh.preciseIntersect(ref localRay, out contact)
&& contact < localRayContact) {
localRayContact = contact;
}
}
return localRayContact < float.PositiveInfinity;
}
public virtual bool PreciseIntersect(ref SSRay worldSpaceRay, ref float distanceAlongRay)
{
return true;
}
// Ray to AABB (AxisAlignedBoundingBox)
// http://gamedev.stackexchange.com/questions/18436/most-efficient-aabb-vs-ray-collision-algorithms
public static bool intersectRayAABox2(SSRay ray, SSAABB box, ref float tnear, ref float tfar)
{
Vector3d T_1 = new Vector3d();
Vector3d T_2 = new Vector3d(); // vectors to hold the T-values for every direction
double t_near = double.MinValue; // maximums defined in float.h
double t_far = double.MaxValue;
for (int i = 0; i < 3; i++){ //we test slabs in every direction
if (ray.dir[i] == 0){ // ray parallel to planes in this direction
if ((ray.pos[i] < box.Min[i]) || (ray.pos[i] > box.Max[i])) {
return false; // parallel AND outside box : no intersection possible
}
} else { // ray not parallel to planes in this direction
T_1[i] = (box.Min[i] - ray.pos[i]) / ray.dir[i];
T_2[i] = (box.Max[i] - ray.pos[i]) / ray.dir[i];
if(T_1[i] > T_2[i]){ // we want T_1 to hold values for intersection with near plane
var swp = T_2; // swap
T_1 = swp; T_2 = T_1;
}
if (T_1[i] > t_near){
t_near = T_1[i];
}
if (T_2[i] < t_far){
t_far = T_2[i];
}
if( (t_near > t_far) || (t_far < 0) ){
return false;
}
}
}
tnear = (float)t_near; tfar = (float)t_far; // put return values in place
return true; // if we made it here, there was an intersection - YAY
}
public static bool intersectRayAABox1(SSRay ray, SSAABB box, ref float tnear, ref float tfar)
{
// r.dir is unit direction vector of ray
Vector3 dirfrac = new Vector3();
float t;
dirfrac.X = 1.0f / ray.dir.X;
dirfrac.Y = 1.0f / ray.dir.Y;
dirfrac.Z = 1.0f / ray.dir.Z;
// lb is the corner of AABB with minimal coordinates - left bottom, rt is maximal corner
// r.org is origin of ray
float t1 = (box.Min.X - ray.pos.X)*dirfrac.X;
float t2 = (box.Max.X - ray.pos.X)*dirfrac.X;
float t3 = (box.Min.Y - ray.pos.Y)*dirfrac.Y;
float t4 = (box.Max.Y - ray.pos.Y)*dirfrac.Y;
float t5 = (box.Min.Z - ray.pos.Z)*dirfrac.Z;
float t6 = (box.Max.Z - ray.pos.Z)*dirfrac.Z;
float tmin = Math.Max(Math.Max(Math.Min(t1, t2), Math.Min(t3, t4)), Math.Min(t5, t6));
float tmax = Math.Min(Math.Min(Math.Max(t1, t2), Math.Max(t3, t4)), Math.Max(t5, t6));
// if tmax < 0, ray (line) is intersecting AABB, but whole AABB is behing us
if (tmax < 0)
{
t = tmax;
return false;
}
// if tmin > tmax, ray doesn't intersect AABB
if (tmin > tmax)
{
t = tmax;
return false;
}
t = tmin;
return true;
}
public override bool PreciseIntersect(ref SSRay worldSpaceRay, ref float distanceAlongRay)
{
SSRay localRay = worldSpaceRay.Transformed(this.worldMat.Inverted());
SSAbstractMesh abstrMesh = this.mesh as SSAbstractMesh;
float nearestLocalRayContact = float.PositiveInfinity;
if (useBVHForIntersections)
{
if (_bvh == null)
{
_bvh = new SSInstanceBVH(this.instanceData);
for (int i = 0; i < instanceData.activeBlockLength; ++i)
{
if (instanceData.isValid(i))
{
_bvh.addObject(i);
}
}
}
List <ssBVHNode <int> > nodesHit = _bvh.traverseRay(localRay);
foreach (var node in nodesHit)
{
if (!node.IsLeaf)
{
continue;
}
foreach (int i in node.gobjects)
{
if (!instanceData.isValid(i))
{
continue;
}
float localContact;
if (_perInstanceIntersectionTest(abstrMesh, i, ref localRay, out localContact))
{
if (localContact < nearestLocalRayContact)
{
nearestLocalRayContact = localContact;
}
}
}
}
}
else
{
// no BVH is used
for (int i = 0; i < instanceData.activeBlockLength; ++i)
{
if (!instanceData.isValid(i))
{
continue;
}
float localContact;
if (_perInstanceIntersectionTest(abstrMesh, i, ref localRay, out localContact))
{
if (localContact < nearestLocalRayContact)
{
nearestLocalRayContact = localContact;
}
}
}
}
if (nearestLocalRayContact < float.PositiveInfinity)
{
Vector3 localContactPt = localRay.pos + nearestLocalRayContact * localRay.dir;
Vector3 worldContactPt = Vector3.Transform(localContactPt, this.worldMat);
distanceAlongRay = (worldContactPt - worldSpaceRay.pos).Length;
return(true);
}
else
{
distanceAlongRay = float.PositiveInfinity;
return(false);
}
}
public SSObject Intersect(ref SSRay worldSpaceRay)
{
SSObject nearestIntersection = null;
float nearestDistance = float.MinValue;
// distances get "smaller" as they move in camera direction for some reason (why?)
foreach (var obj in objects) {
float distanceAlongRay;
if (obj.Selectable && obj.Intersect(ref worldSpaceRay, out distanceAlongRay)) {
// intersection must be in front of the camera ( < 0.0 )
if (distanceAlongRay < 0.0) {
Console.WriteLine("intersect: [{0}] @distance: {1}", obj.Name, distanceAlongRay);
// then we want the nearest one (numerically biggest
if (distanceAlongRay > nearestDistance) {
nearestDistance = distanceAlongRay;
nearestIntersection = obj;
}
}
}
}
return nearestIntersection;
}
public virtual bool preciseIntersect(ref SSRay localRay, out float localRayContact)
{
localRayContact = 0f;
return(true);
}
// http://www.geometrictools.com/Documentation/DistancePointLine.pdf
public static float DistanceToLine_3(SSRay ray, Vector3 point)
{
float t0 = Vector3.Dot(ray.dir, ( point - ray.pos) ) / Vector3.Dot(ray.dir,ray.dir);
float distance = (point - (ray.pos + (t0 * ray.dir))).Length;
return distance;
}
public virtual bool Intersect(ref SSRay worldSpaceRay, out float distanceAlongRay)
{
distanceAlongRay = 0.0f;
if (localBoundingSphereRadius > 0f) {
var objBoundingSphere = worldBoundingSphere;
if (objBoundingSphere.IntersectsRay(ref worldSpaceRay, out distanceAlongRay)) {
return PreciseIntersect(ref worldSpaceRay, ref distanceAlongRay);
}
}
distanceAlongRay = 0f;
return false;
}
//---------------------
public override bool preciseIntersect(ref SSRay localRay, out float nearestLocalRayContact)
{
nearestLocalRayContact = float.PositiveInfinity;
if (useBVHForIntersections)
{
if (_bvh == null && _vbo != null && _ibo != null)
{
// rebuilding BVH
// TODO try updating instead of rebuilding?
_bvh = new SSIndexedMeshTrianglesBVH(_vbo, _ibo);
for (UInt16 triIdx = 0; triIdx < _ibo.numIndices / 3; ++triIdx)
{
_bvh.addObject(triIdx);
}
}
if (_bvh != null)
{
List <ssBVHNode <UInt16> > nodesHit = _bvh.traverseRay(localRay);
foreach (var node in nodesHit)
{
if (!node.IsLeaf)
{
continue;
}
foreach (UInt16 triIdx in node.gobjects)
{
Vector3 v0, v1, v2;
_readTriangleVertices(triIdx, out v0, out v1, out v2);
float contact;
if (OpenTKHelper.TriangleRayIntersectionTest(
ref v0, ref v1, ref v2, ref localRay.pos, ref localRay.dir, out contact))
{
if (contact < nearestLocalRayContact)
{
nearestLocalRayContact = contact;
}
}
}
}
}
}
else
{
_bvh = null;
// slow, tedious intersection test
int numTri = lastAssignedIndices.Length / 3;
for (UInt16 triIdx = 0; triIdx < numTri; ++triIdx)
{
Vector3 v0, v1, v2;
_readTriangleVertices(triIdx, out v0, out v1, out v2);
float contact;
if (OpenTKHelper.TriangleRayIntersectionTest(
ref v0, ref v1, ref v2, ref localRay.pos, ref localRay.dir, out contact))
{
if (contact < nearestLocalRayContact)
{
nearestLocalRayContact = contact;
}
}
}
}
return(nearestLocalRayContact < float.PositiveInfinity);
}
public SSObject Intersect(ref SSRay worldSpaceRay, out float nearestDistance)
{
SSObject nearestIntersection = null;
nearestDistance = float.PositiveInfinity;
// distances get "smaller" as they move in camera direction for some reason (why?)
foreach (var obj in objects) {
float distanceAlongRay;
DateTime start = DateTime.Now;
if (obj.selectable && obj.Intersect(ref worldSpaceRay, out distanceAlongRay)) {
// intersection must be in front of the camera ( < 0.0 )
if (distanceAlongRay > 0.0) {
Console.WriteLine("intersect: [{0}] @distance: {1} in {2}ms", obj.Name, distanceAlongRay, (DateTime.Now - start).TotalMilliseconds);
// then we want the nearest one (numerically biggest
if (distanceAlongRay < nearestDistance) {
nearestDistance = distanceAlongRay;
nearestIntersection = obj;
}
}
}
}
return nearestIntersection;
}
public static float DistanceToLine_2(SSRay ray, Vector3 point)
{
return(Vector3.Cross(ray.dir, point - ray.pos).Length);
}
public override bool PreciseIntersect(ref SSRay worldSpaceRay, ref float distanceAlongRay)
{
// for now, particle systems don't intersect with anything
// TODO: figure out how to do this.
return(false);
}