Implement raycasting for capsule shape

This commit is contained in:
Daniel Chappuis 2014-09-20 17:00:32 +02:00
parent 78193d9b03
commit 25c11c6d6a
3 changed files with 322 additions and 22 deletions

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@ -25,6 +25,7 @@
// Libraries
#include "CapsuleShape.h"
#include "collision/ProxyShape.h"
#include "configuration.h"
#include <cassert>
@ -145,18 +146,279 @@ bool CapsuleShape::testPointInside(const Vector3& localPoint, ProxyShape* proxyS
// Raycast method
bool CapsuleShape::raycast(const Ray& ray, ProxyShape* proxyShape) const {
// TODO : Normalize the ray direction
// Transform the ray direction and origin in local-space coordinates
const Transform localToWorldTransform = proxyShape->getLocalToWorldTransform();
const Transform worldToLocalTransform = localToWorldTransform.getInverse();
Vector3 origin = worldToLocalTransform * ray.origin;
Vector3 n = worldToLocalTransform.getOrientation() * ray.direction.getUnit();
// TODO : Implement this method
const decimal epsilon = decimal(0.00001);
Vector3 p(decimal(0), -mHalfHeight, decimal(0));
Vector3 q(decimal(0), mHalfHeight, decimal(0));
Vector3 d = q - p;
Vector3 m = origin - p;
decimal t;
decimal mDotD = m.dot(d);
decimal nDotD = n.dot(d);
decimal dDotD = d.dot(d);
decimal mDotN = m.dot(n);
decimal a = dDotD - nDotD * nDotD;
decimal k = m.dot(m) - mRadius * mRadius;
decimal c = dDotD * k - mDotD * mDotD;
// If the ray is parallel to the cylinder axis
if (std::abs(a) < epsilon) {
// If the origin is outside the surface of the cylinder, we return no hit
if (c > decimal(0.0)) return false;
// Here we know that the segment intersect an endcap of the cylinder
// If the ray intersects with the "p" endcap of the capsule
if (mDotD < decimal(0.0)) {
// Check intersection with the sphere "p" endcap of the capsule
return raycastWithSphereEndCap(origin, n, p);
}
else if (mDotD > dDotD) { // If the ray intersects with the "q" endcap of the cylinder
// Check intersection with the sphere "q" endcap of the capsule
return raycastWithSphereEndCap(origin, n, q);
}
else { // If the origin is inside the cylinder, we return no hit
return false;
}
}
decimal b = dDotD * mDotN - nDotD * mDotD;
decimal discriminant = b * b - a * c;
// If the discriminant is negative, no real roots and therfore, no hit
if (discriminant < decimal(0.0)) return false;
// Compute the smallest root (first intersection along the ray)
decimal t0 = t = (-b - std::sqrt(discriminant)) / a;
// If the intersection is outside the cylinder on "p" endcap side
decimal value = mDotD + t * nDotD;
if (value < decimal(0.0)) {
// Check intersection with the sphere "p" endcap of the capsule
return raycastWithSphereEndCap(origin, n, p);
}
else if (value > dDotD) { // If the intersection is outside the cylinder on the "q" side
// Check intersection with the sphere "q" endcap of the capsule
return raycastWithSphereEndCap(origin, n, q);
}
// If the intersection is behind the origin of the ray, we return no hit
return (t0 >= decimal(0.0));
}
// Raycast method with feedback information
bool CapsuleShape::raycast(const Ray& ray, RaycastInfo& raycastInfo, ProxyShape* proxyShape,
decimal distance) const {
// TODO : Normalize the ray direction
// Transform the ray direction and origin in local-space coordinates
const Transform localToWorldTransform = proxyShape->getLocalToWorldTransform();
const Transform worldToLocalTransform = localToWorldTransform.getInverse();
Vector3 origin = worldToLocalTransform * ray.origin;
Vector3 n = worldToLocalTransform.getOrientation() * ray.direction.getUnit();
const decimal epsilon = decimal(0.00001);
Vector3 p(decimal(0), -mHalfHeight, decimal(0));
Vector3 q(decimal(0), mHalfHeight, decimal(0));
Vector3 d = q - p;
Vector3 m = origin - p;
decimal t;
decimal mDotD = m.dot(d);
decimal nDotD = n.dot(d);
decimal dDotD = d.dot(d);
decimal mDotN = m.dot(n);
decimal a = dDotD - nDotD * nDotD;
decimal k = m.dot(m) - mRadius * mRadius;
decimal c = dDotD * k - mDotD * mDotD;
// If the ray is parallel to the capsule axis
if (std::abs(a) < epsilon) {
// If the origin is outside the surface of the capusle's cylinder, we return no hit
if (c > decimal(0.0)) return false;
// Here we know that the segment intersect an endcap of the capsule
// If the ray intersects with the "p" endcap of the capsule
if (mDotD < decimal(0.0)) {
// Check intersection between the ray and the "p" sphere endcap of the capsule
Vector3 hitLocalPoint;
decimal hitDistance;
if (raycastWithSphereEndCap(origin, n, p, distance, hitLocalPoint, hitDistance)) {
raycastInfo.body = proxyShape->getBody();
raycastInfo.proxyShape = proxyShape;
raycastInfo.distance = hitDistance;
raycastInfo.worldPoint = localToWorldTransform * hitLocalPoint;
Vector3 normalDirection = (hitLocalPoint - p).getUnit();
raycastInfo.worldNormal = localToWorldTransform.getOrientation() * normalDirection;
return true;
}
// TODO : Implement this method
return false;
}
else if (mDotD > dDotD) { // If the ray intersects with the "q" endcap of the cylinder
// Check intersection between the ray and the "q" sphere endcap of the capsule
Vector3 hitLocalPoint;
decimal hitDistance;
if (raycastWithSphereEndCap(origin, n, q, distance, hitLocalPoint, hitDistance)) {
raycastInfo.body = proxyShape->getBody();
raycastInfo.proxyShape = proxyShape;
raycastInfo.distance = hitDistance;
raycastInfo.worldPoint = localToWorldTransform * hitLocalPoint;
Vector3 normalDirection = (hitLocalPoint - q).getUnit();
raycastInfo.worldNormal = localToWorldTransform.getOrientation() * normalDirection;
return true;
}
return false;
}
else { // If the origin is inside the cylinder, we return no hit
return false;
}
}
decimal b = dDotD * mDotN - nDotD * mDotD;
decimal discriminant = b * b - a * c;
// If the discriminant is negative, no real roots and therfore, no hit
if (discriminant < decimal(0.0)) return false;
// Compute the smallest root (first intersection along the ray)
decimal t0 = t = (-b - std::sqrt(discriminant)) / a;
// If the intersection is outside the finite cylinder of the capsule on "p" endcap side
decimal value = mDotD + t * nDotD;
if (value < decimal(0.0)) {
// Check intersection between the ray and the "p" sphere endcap of the capsule
Vector3 hitLocalPoint;
decimal hitDistance;
if (raycastWithSphereEndCap(origin, n, p, distance, hitLocalPoint, hitDistance)) {
raycastInfo.body = proxyShape->getBody();
raycastInfo.proxyShape = proxyShape;
raycastInfo.distance = hitDistance;
raycastInfo.worldPoint = localToWorldTransform * hitLocalPoint;
Vector3 normalDirection = (hitLocalPoint - p).getUnit();
raycastInfo.worldNormal = localToWorldTransform.getOrientation() * normalDirection;
return true;
}
return false;
}
else if (value > dDotD) { // If the intersection is outside the finite cylinder on the "q" side
// Check intersection between the ray and the "q" sphere endcap of the capsule
Vector3 hitLocalPoint;
decimal hitDistance;
if (raycastWithSphereEndCap(origin, n, q, distance, hitLocalPoint, hitDistance)) {
raycastInfo.body = proxyShape->getBody();
raycastInfo.proxyShape = proxyShape;
raycastInfo.distance = hitDistance;
raycastInfo.worldPoint = localToWorldTransform * hitLocalPoint;
Vector3 normalDirection = (hitLocalPoint - q).getUnit();
raycastInfo.worldNormal = localToWorldTransform.getOrientation() * normalDirection;
return true;
}
return false;
}
t = t0;
// If the intersection is behind the origin of the ray or beyond the maximum
// raycasting distance, we return no hit
if (t < decimal(0.0) || t > distance) return false;
// Compute the hit information
Vector3 localHitPoint = origin + t * n;
raycastInfo.body = proxyShape->getBody();
raycastInfo.proxyShape = proxyShape;
raycastInfo.distance = t;
raycastInfo.worldPoint = localToWorldTransform * localHitPoint;
Vector3 v = localHitPoint - p;
Vector3 w = (v.dot(d) / d.lengthSquare()) * d;
Vector3 normalDirection = (localHitPoint - (p + w)).getUnit();
raycastInfo.worldNormal = localToWorldTransform.getOrientation() * normalDirection;
return true;
}
// Raycasting method between a ray one of the two spheres end cap of the capsule
bool CapsuleShape::raycastWithSphereEndCap(const Vector3& rayOrigin, const Vector3& rayDirection,
const Vector3& sphereCenter, decimal maxDistance,
Vector3& hitLocalPoint, decimal& hitDistance) const {
Vector3 m = rayOrigin - sphereCenter;
decimal c = m.dot(m) - mRadius * mRadius;
// If the origin of the ray is inside the sphere, we return no intersection
if (c < decimal(0.0)) return false;
decimal b = m.dot(rayDirection);
// If the origin of the ray is outside the sphere and the ray
// is pointing away from the sphere and there is no intersection
if (c >= decimal(0.0) && b > decimal(0.0)) return false;
// Compute the discriminant of the quadratic equation
decimal discriminant = b * b - c;
// If the discriminant is negative, there is no intersection
if (discriminant < decimal(0.0)) return false;
// Compute the solution "t" closest to the origin
decimal t = -b - std::sqrt(discriminant);
assert(t >= decimal(0.0));
// If the intersection distance is larger than the allowed distance, return no intersection
if (t > maxDistance) return false;
// Compute the hit point and distance
hitLocalPoint = rayOrigin + t * rayDirection;
hitDistance = t;
return true;
}
// Raycasting method between a ray one of the two spheres end cap of the capsule
/// This method returns true if there is an intersection and false otherwise but does not
/// compute the intersection point.
bool CapsuleShape::raycastWithSphereEndCap(const Vector3& rayOrigin, const Vector3& rayDirection,
const Vector3& sphereCenter) const {
Vector3 m = rayOrigin - sphereCenter;
decimal c = m.dot(m) - mRadius * mRadius;
// If the origin of the ray is inside the sphere, we return no intersection
if (c < decimal(0.0)) return false;
decimal b = m.dot(rayDirection);
// If the origin of the ray is outside the sphere and the ray
// is pointing away from the sphere and there is no intersection
if (c >= decimal(0.0) && b > decimal(0.0)) return false;
// Compute the discriminant of the quadratic equation
decimal discriminant = b * b - c;
// If the discriminant is negative, there is no intersection
return (discriminant >= decimal(0.0));
}

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@ -82,6 +82,15 @@ class CapsuleShape : public CollisionShape {
virtual bool raycast(const Ray& ray, RaycastInfo& raycastInfo, ProxyShape* proxyShape,
decimal distance = RAYCAST_INFINITY_DISTANCE) const;
/// Raycasting method between a ray one of the two spheres end cap of the capsule
bool raycastWithSphereEndCap(const Vector3& rayOrigin, const Vector3& rayDirection,
const Vector3& sphereCenter, decimal maxDistance,
Vector3& hitLocalPoint, decimal& hitDistance) const;
// Raycasting method between a ray one of the two spheres end cap of the capsule
bool raycastWithSphereEndCap(const Vector3& rayOrigin, const Vector3& rayDirection,
const Vector3& sphereCenter) const;
public :
// -------------------- Methods -------------------- //

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@ -506,41 +506,70 @@ class TestRaycast : public Test {
void testCapsule() {
// ----- Test feedback data ----- //
Vector3 origin = mLocalShapeToWorld * Vector3(0 , 10, 0);
Vector3 origin = mLocalShapeToWorld * Vector3(6 , 1, 0);
const Matrix3x3 mLocalToWorldMatrix = mLocalShapeToWorld.getOrientation().getMatrix();
Vector3 direction = mLocalToWorldMatrix * Vector3(0, -3, 0);
Vector3 direction = mLocalToWorldMatrix * Vector3(-2, 0, 0);
Ray ray(origin, direction);
Vector3 hitPoint = mLocalShapeToWorld * Vector3(0, 7, 0);
Vector3 hitPoint = mLocalShapeToWorld * Vector3(2, 1, 0);
Vector3 origin2 = mLocalShapeToWorld * Vector3(0 , 10, 0);
Vector3 direction2 = mLocalToWorldMatrix * Vector3(0, -3, 0);
Ray rayTop(origin2, direction2);
Vector3 hitPointTop = mLocalShapeToWorld * Vector3(0, decimal(4.5), 0);
Vector3 origin3 = mLocalShapeToWorld * Vector3(0 , -10, 0);
Vector3 direction3 = mLocalToWorldMatrix * Vector3(0, 3, 0);
Ray rayBottom(origin3, direction3);
Vector3 hitPointBottom = mLocalShapeToWorld * Vector3(0, decimal(-4.5), 0);
// CollisionWorld::raycast()
RaycastInfo raycastInfo;
test(mWorld->raycast(ray, raycastInfo));
test(raycastInfo.body == mCapsuleBody);
test(raycastInfo.proxyShape == mCapsuleShape);
test(approxEqual(raycastInfo.distance, 6));
test(approxEqual(raycastInfo.worldPoint.x, hitPoint.x));
test(approxEqual(raycastInfo.worldPoint.y, hitPoint.y));
test(approxEqual(raycastInfo.worldPoint.z, hitPoint.z));
test(approxEqual(raycastInfo.distance, 4, epsilon));
test(approxEqual(raycastInfo.worldPoint.x, hitPoint.x, epsilon));
test(approxEqual(raycastInfo.worldPoint.y, hitPoint.y, epsilon));
test(approxEqual(raycastInfo.worldPoint.z, hitPoint.z, epsilon));
// CollisionBody::raycast()
RaycastInfo raycastInfo2;
test(mCapsuleBody->raycast(ray, raycastInfo2));
test(raycastInfo2.body == mCapsuleBody);
test(raycastInfo2.proxyShape == mCapsuleShape);
test(approxEqual(raycastInfo2.distance, 6));
test(approxEqual(raycastInfo2.worldPoint.x, hitPoint.x));
test(approxEqual(raycastInfo2.worldPoint.y, hitPoint.y));
test(approxEqual(raycastInfo2.worldPoint.z, hitPoint.z));
test(approxEqual(raycastInfo2.distance, 4, epsilon));
test(approxEqual(raycastInfo2.worldPoint.x, hitPoint.x, epsilon));
test(approxEqual(raycastInfo2.worldPoint.y, hitPoint.y, epsilon));
test(approxEqual(raycastInfo2.worldPoint.z, hitPoint.z, epsilon));
// ProxyCollisionShape::raycast()
RaycastInfo raycastInfo3;
test(mCapsuleShape->raycast(ray, raycastInfo3));
test(raycastInfo3.body == mCapsuleBody);
test(raycastInfo3.proxyShape == mCapsuleShape);
test(approxEqual(raycastInfo3.distance, 6));
test(approxEqual(raycastInfo3.worldPoint.x, hitPoint.x));
test(approxEqual(raycastInfo3.worldPoint.y, hitPoint.y));
test(approxEqual(raycastInfo3.worldPoint.z, hitPoint.z));
test(approxEqual(raycastInfo3.distance, 4, epsilon));
test(approxEqual(raycastInfo3.worldPoint.x, hitPoint.x, epsilon));
test(approxEqual(raycastInfo3.worldPoint.y, hitPoint.y, epsilon));
test(approxEqual(raycastInfo3.worldPoint.z, hitPoint.z, epsilon));
RaycastInfo raycastInfo4;
test(mCapsuleShape->raycast(rayTop, raycastInfo4));
test(raycastInfo4.body == mCapsuleBody);
test(raycastInfo4.proxyShape == mCapsuleShape);
test(approxEqual(raycastInfo4.distance, decimal(5.5), epsilon));
test(approxEqual(raycastInfo4.worldPoint.x, hitPointTop.x, epsilon));
test(approxEqual(raycastInfo4.worldPoint.y, hitPointTop.y, epsilon));
test(approxEqual(raycastInfo4.worldPoint.z, hitPointTop.z, epsilon));
// ProxyCollisionShape::raycast()
RaycastInfo raycastInfo5;
test(mCapsuleShape->raycast(rayBottom, raycastInfo5));
test(raycastInfo5.body == mCapsuleBody);
test(raycastInfo5.proxyShape == mCapsuleShape);
test(approxEqual(raycastInfo5.distance, decimal(5.5), epsilon));
test(approxEqual(raycastInfo5.worldPoint.x, hitPointBottom.x, epsilon));
test(approxEqual(raycastInfo5.worldPoint.y, hitPointBottom.y, epsilon));
test(approxEqual(raycastInfo5.worldPoint.z, hitPointBottom.z, epsilon));
Ray ray1(mLocalShapeToWorld * Vector3(0, 0, 0), mLocalToWorldMatrix * Vector3(5, 7, -1));
Ray ray2(mLocalShapeToWorld * Vector3(5, 11, 7), mLocalToWorldMatrix * Vector3(4, 6, 7));
@ -552,7 +581,7 @@ class TestRaycast : public Test {
Ray ray8(mLocalShapeToWorld * Vector3(-4, 9, 0), mLocalToWorldMatrix * Vector3(1, 0, 0));
Ray ray9(mLocalShapeToWorld * Vector3(0, -9, -4), mLocalToWorldMatrix * Vector3(0, 5, 0));
Ray ray10(mLocalShapeToWorld * Vector3(-4, 0, -6), mLocalToWorldMatrix * Vector3(0, 0, 8));
Ray ray11(mLocalShapeToWorld * Vector3(4, 1, 2), mLocalToWorldMatrix * Vector3(-4, 0, 0));
Ray ray11(mLocalShapeToWorld * Vector3(4, 1, 1.5), mLocalToWorldMatrix * Vector3(-4, 0, 0));
Ray ray12(mLocalShapeToWorld * Vector3(1, 9, -1), mLocalToWorldMatrix * Vector3(0, -3, 0));
Ray ray13(mLocalShapeToWorld * Vector3(-1, 2, 3), mLocalToWorldMatrix * Vector3(0, 0, -8));
Ray ray14(mLocalShapeToWorld * Vector3(-3, 2, -2), mLocalToWorldMatrix * Vector3(4, 0, 0));