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feat(picking): fix "intersect with triangle->intersected point" bug
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description
when ray->origin is in the model, sometimes the intersected point is the opposite point of the two intersected points!

reason

solution
RayUtils use another "checkIntersectTriangle" function based on three.js
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@yyc-git
yyc-git committed Jan 18, 2019
1 parent a2b0b3b commit d88ddb1
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Showing 2 changed files with 184 additions and 139 deletions.
321 changes: 183 additions & 138 deletions src/core/utils/engine/job/init/initPickingJob/RayUtils.re
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Original file line number Diff line number Diff line change
Expand Up @@ -213,76 +213,6 @@ let isIntersectSphere =
};
}; */

/* let checkIntersectTriangle =
(isBackfaceCulling, va, vb, vc, {origin, direction} as ray) => {
let edge1 = Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, vb, va);
let edge2 = Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, vc, va);
let normal = Wonderjs.Vector3Service.cross(edge1, edge2);
/* Solve Q + t*D = b1*E1 + b2*E2 (Q = kDiff, D = ray direction,
E1 = kEdge1, E2 = kEdge2, N = Cross(E1,E2)) by
|Dot(D,N)|*b1 = sign(Dot(D,N))*Dot(D,Cross(Q,E2))
|Dot(D,N)|*b2 = sign(Dot(D,N))*Dot(D,Cross(E1,Q))
|Dot(D,N)|*t = -sign(Dot(D,N))*Dot(Q,N) */

let ddn = Vector3Service.dot(direction, normal);
let sign = 0.;

let (isEndCheck, sign, ddn) =
if (ddn > 0.) {
isBackfaceCulling ? (Some(false), sign, ddn) : (None, 1., ddn);
} else if (ddn < 0.) {
(None, (-1.), -. ddn);
} else {
(Some(false), sign, ddn);
};

switch (isEndCheck) {
| Some(isIntersect) => None
| None =>
let diff =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, origin, va);

let edge2 = Wonderjs.Vector3Service.cross(diff, edge2);

let ddqxe2 =
sign
*. Vector3Service.dot(
direction,
/* Wonderjs.Vector3Service.cross(diff, edge2), */
edge2,
);

/* b1 < 0, no intersection */
if (ddqxe2 < 0.) {
None;
} else {
let dde1xq =
sign
*. Vector3Service.dot(
direction,
Wonderjs.Vector3Service.cross(edge1, diff),
);

/* b2 < 0, no intersection */
if (dde1xq < 0.) {
None;
} else if
/* b1+b2 > 1, no intersection */
(ddqxe2 +. dde1xq > ddn) {
None;
} else {
/* Line intersects triangle, check if ray does. */
let qdn = -. sign *. Vector3Service.dot(diff, normal);

qdn < 0. ? None : Some(_at(qdn /. ddn, ray));
};
};
};
}; */

let _checkIntersectTriangleForFrontAndNoneCull =
(
(det, edge1, edge2, pvec),
Expand Down Expand Up @@ -329,86 +259,201 @@ let _checkIntersectTriangleForFrontAndNoneCull =
let checkIntersectTriangle =
(
cullType: InitPickingJobType.cull,
v0,
v1,
v2,
{origin, direction}: InitPickingJobType.ray,
va,
vb,
vc,
({origin, direction}: InitPickingJobType.ray) as ray,
) =>
switch (cullType) {
| Both => None
| _ =>
| Front =>
let epsilon = 0.000001;

let edge1 =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, v1, v0);
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, vb, va);

let edge2 =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, v2, v0);
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, vc, va);

let pvec = Wonderjs.Vector3Service.cross(direction, edge2);

let det = Vector3Service.dot(edge1, pvec);

switch (cullType) {
| Back =>
det < epsilon ?
None :
{
let tvec =
Wonderjs.Vector3Service.sub(
Wonderjs.Vector3Type.Float,
origin,
v0,
);

let u = Vector3Service.dot(tvec, pvec);

u < 0. || u > det ?
None :
{
let qvec = Wonderjs.Vector3Service.cross(tvec, edge1);

let v = Vector3Service.dot(direction, qvec);

v < 0. || u +. v > det ?
None :
{
let t = Vector3Service.dot(edge2, qvec) /. det;

/* var t = dot(edge2, qvec) / det;
out[0] = origin[0] + t * direction[0];
out[1] = origin[1] + t * direction[1];
out[2] = origin[2] + t * direction[2];
return out; */
Some(
Wonderjs.Vector3Service.add(
Wonderjs.Vector3Type.Float,
origin,
Vector3Service.multiplyScalar(direction, t),
),
);
};
};
}
| Front =>
det > epsilon ?
None :
_checkIntersectTriangleForFrontAndNoneCull(
(det, edge1, edge2, pvec),
v0,
v1,
v2,
{origin, direction},
)
det > epsilon ?
None :
_checkIntersectTriangleForFrontAndNoneCull(
(det, edge1, edge2, pvec),
va,
vb,
vc,
{origin, direction}: InitPickingJobType.ray,
);
| _ =>
let edge1 =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, vb, va);

let edge2 =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, vc, va);

let normal = Wonderjs.Vector3Service.cross(edge1, edge2);

/*
//from http://www.geometrictools.com/GTEngine/Include/Mathematics/GteIntrRay3Triangle3.h
Solve Q + t*D = b1*E1 + b2*E2 (Q = kDiff, D = ray direction,
E1 = kEdge1, E2 = kEdge2, N = Cross(E1,E2)) by
|Dot(D,N)|*b1 = sign(Dot(D,N))*Dot(D,Cross(Q,E2))
|Dot(D,N)|*b2 = sign(Dot(D,N))*Dot(D,Cross(E1,Q))
|Dot(D,N)|*t = -sign(Dot(D,N))*Dot(Q,N) */

let ddn = Vector3Service.dot(direction, normal);
let sign = 0.;

let isBackfaceCulling =
switch (cullType) {
| Back => true
| None => false
};

let (isEndCheck, sign, ddn) =
if (ddn > 0.) {
isBackfaceCulling ? (Some(false), sign, ddn) : (None, 1., ddn);
} else if (ddn < 0.) {
(None, (-1.), -. ddn);
} else {
(Some(false), sign, ddn);
};

switch (isEndCheck) {
| Some(isIntersect) => None
| None =>
det > -. epsilon && det < epsilon ?
None :
_checkIntersectTriangleForFrontAndNoneCull(
(det, edge1, edge2, pvec),
v0,
v1,
v2,
{origin, direction},
)
let diff =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, origin, va);

let edge2 = Wonderjs.Vector3Service.cross(diff, edge2);

let ddqxe2 =
sign
*. Vector3Service.dot(
direction,
/* Wonderjs.Vector3Service.cross(diff, edge2), */
edge2,
);

/* b1 < 0, no intersection */
if (ddqxe2 < 0.) {
None;
} else {
let dde1xq =
sign
*. Vector3Service.dot(
direction,
Wonderjs.Vector3Service.cross(edge1, diff),
);

/* b2 < 0, no intersection */
if (dde1xq < 0.) {
None;
} else if
/* b1+b2 > 1, no intersection */
(ddqxe2 +. dde1xq > ddn) {
None;
} else {
/* Line intersects triangle, check if ray does. */
let qdn = -. sign *. Vector3Service.dot(diff, normal);

qdn < 0. ? None : Some(_at(qdn /. ddn, ray));
};
};
};
};
};

/*
need fix bug: when ray->origin is in the model, sometimes the intersected point is the opposite point of the two intersected points!
let checkIntersectTriangle =
(
cullType: InitPickingJobType.cull,
v0,
v1,
v2,
{origin, direction}: InitPickingJobType.ray,
) =>
switch (cullType) {
| Both => None
| _ =>
let epsilon = 0.000001;
let edge1 =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, v1, v0);
let edge2 =
Wonderjs.Vector3Service.sub(Wonderjs.Vector3Type.Float, v2, v0);
let pvec = Wonderjs.Vector3Service.cross(direction, edge2);
let det = Vector3Service.dot(edge1, pvec);
switch (cullType) {
| Back =>
det < epsilon ?
None :
{
let tvec =
Wonderjs.Vector3Service.sub(
Wonderjs.Vector3Type.Float,
origin,
v0,
);
let u = Vector3Service.dot(tvec, pvec);
u < 0. || u > det ?
None :
{
let qvec = Wonderjs.Vector3Service.cross(tvec, edge1);
let v = Vector3Service.dot(direction, qvec);
v < 0. || u +. v > det ?
None :
{
let t = Vector3Service.dot(edge2, qvec) /. det;
/* var t = dot(edge2, qvec) / det;
out[0] = origin[0] + t * direction[0];
out[1] = origin[1] + t * direction[1];
out[2] = origin[2] + t * direction[2];
return out; */
Some(
Wonderjs.Vector3Service.add(
Wonderjs.Vector3Type.Float,
origin,
Vector3Service.multiplyScalar(direction, t),
),
);
};
};
}
| Front =>
det > epsilon ?
None :
_checkIntersectTriangleForFrontAndNoneCull(
(det, edge1, edge2, pvec),
v0,
v1,
v2,
{origin, direction},
)
| None =>
det > -. epsilon && det < epsilon ?
None :
_checkIntersectTriangleForFrontAndNoneCull(
(det, edge1, edge2, pvec),
v0,
v1,
v2,
{origin, direction},
)
};
}; */
2 changes: 1 addition & 1 deletion test/integration/job/initPickingJob_test.re
View file
Original file line number Diff line number Diff line change
Expand Up @@ -613,7 +613,7 @@ let _ =
~viewHeight=200,
~offsetLeft=10,
~offsetTop=20,
~cameraPos=(0., 0., 0.),
~cameraPos=(0., 0., 2.),
~gameObjectPos=(0., 0., 0.),
~gameObjectEulerAngles=(0., 0., 0.),
~createGameObjectFunc=_createCube,
Expand Down

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