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Improved stability of sphere vs convex polyhedron except for one edge case

This commit is contained in:
Diren D Bharwani 2022-12-31 18:43:46 +08:00
parent 136b7e7bfc
commit 3a7336fe15
8 changed files with 304 additions and 250 deletions
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10
Assets/Scenes/PhysicsSandbox.shade
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@ -4,9 +4,9 @@
NumberOfChildren: 0
Components:
Transform Component:
Translate: {x: 2.58071685, y: 0.456140399, z: 0}
Rotate: {x: -0, y: 0, z: 0.469853699}
Scale: {x: 4.61071014, y: 0.999995053, z: 1}
Translate: {x: 2.72256827, y: 0.501797795, z: -0.0273017883}
Rotate: {x: -1.48352849, y: -4.78713309e-06, z: 0.469859391}
Scale: {x: 4.61070776, y: 0.99999392, z: 0.999996722}
IsActive: true
RigidBody Component:
Type: Static
@ -66,7 +66,7 @@
NumberOfChildren: 0
Components:
Transform Component:
Translate: {x: -1.98839664, y: 7.7662077, z: 0}
Translate: {x: -2.49145222, y: 6.17996597, z: 0.811235607}
Rotate: {x: -0, y: 0, z: -0}
Scale: {x: 1, y: 1, z: 1}
IsActive: true
@ -112,7 +112,7 @@
Components:
Transform Component:
Translate: {x: 0, y: 4.09544182, z: 0}
Rotate: {x: -0, y: 0, z: -0.437829614}
Rotate: {x: -0, y: 0, z: 0}
Scale: {x: 4.61071014, y: 0.999995887, z: 1}
IsActive: true
RigidBody Component:

6
SHADE_Engine/src/Physics/Collision/CollisionShapes/SHCollisionShapeLibrary.cpp
View File

@ -71,7 +71,7 @@ namespace SHADE
box->scale = createInfo.Scale;
// Set halfEdge data structure for the box
box->halfEdgeStructure = &boxHalfEdgeDS;
box->halfEdgeStructure = &boxHalfEdgeStructure;
return box;
}
@ -165,10 +165,10 @@ namespace SHADE
for (int j = 0; j < NUM_VERTICES_PER_FACE; ++j)
newFace.vertexIndices.emplace_back(FACE_VERTICES[i][j]);
boxHalfEdgeDS.AddFace(newFace);
boxHalfEdgeStructure.AddFace(newFace);
}
boxHalfEdgeDS.Build();
boxHalfEdgeStructure.Build();
}
} // namespace SHADE

6
SHADE_Engine/src/Physics/Collision/CollisionShapes/SHCollisionShapeLibrary.h
View File

@ -92,10 +92,10 @@ namespace SHADE
/* Data Members */
/*---------------------------------------------------------------------------------*/
SHHalfEdgeStructure boxHalfEdgeDS;
SHHalfEdgeStructure boxHalfEdgeStructure;
Spheres spheres;
Boxes boxes;
Spheres spheres;
Boxes boxes;
// TODO: Add capsules and hulls
/*---------------------------------------------------------------------------------*/

68
SHADE_Engine/src/Physics/Collision/CollisionShapes/SHHalfEdgeStructure.cpp
View File

@ -23,30 +23,6 @@ namespace SHADE
/* Constructors & Destructor Definitions */
/*-----------------------------------------------------------------------------------*/
SHHalfEdgeStructure::HalfEdge::HalfEdge() noexcept
: tailVertexIndex { -1 }
, headVertexIndex { -1 }
, edgeIndex { -1 }
, twinEdgeIndex { -1 }
, faceIndex { -1 }
{}
SHHalfEdgeStructure::HalfEdge::HalfEdge(const HalfEdge& rhs) noexcept
: tailVertexIndex { rhs.tailVertexIndex }
, headVertexIndex { rhs.headVertexIndex }
, edgeIndex { rhs.edgeIndex }
, twinEdgeIndex { rhs.twinEdgeIndex }
, faceIndex { rhs.faceIndex }
{}
SHHalfEdgeStructure::HalfEdge::HalfEdge(HalfEdge&& rhs) noexcept
: tailVertexIndex { rhs.tailVertexIndex }
, headVertexIndex { rhs.headVertexIndex }
, edgeIndex { rhs.edgeIndex }
, twinEdgeIndex { rhs.twinEdgeIndex }
, faceIndex { rhs.faceIndex }
{}
SHHalfEdgeStructure::Face::Face(const Face& rhs) noexcept
: normal { rhs.normal }
{
@ -63,31 +39,6 @@ namespace SHADE
/* Operator Overload Definitions */
/*-----------------------------------------------------------------------------------*/
SHHalfEdgeStructure::HalfEdge& SHHalfEdgeStructure::HalfEdge::operator=(const HalfEdge& rhs) noexcept
{
if (this == &rhs)
return *this;
tailVertexIndex = rhs.tailVertexIndex;
headVertexIndex = rhs.headVertexIndex;
edgeIndex = rhs.edgeIndex ;
twinEdgeIndex = rhs.twinEdgeIndex ;
faceIndex = rhs.faceIndex ;
return *this;
}
SHHalfEdgeStructure::HalfEdge& SHHalfEdgeStructure::HalfEdge::operator=(HalfEdge&& rhs) noexcept
{
tailVertexIndex = rhs.tailVertexIndex;
headVertexIndex = rhs.headVertexIndex;
edgeIndex = rhs.edgeIndex ;
twinEdgeIndex = rhs.twinEdgeIndex ;
faceIndex = rhs.faceIndex ;
return *this;
}
SHHalfEdgeStructure::Face& SHHalfEdgeStructure::Face::operator=(const Face& rhs) noexcept
{
if (this == &rhs)
@ -165,19 +116,19 @@ namespace SHADE
// For each face, build half edges
for (size_t i = 0; i < faces.size(); ++i)
{
const Face& FACE = faces[i];
Face& face = faces[i];
if (FACE.vertexIndices.empty())
if (face.vertexIndices.empty())
{
SHLOGV_CRITICAL("Unable to build convex polyhedron, no vertices have been added to face {}!", i)
return;
}
// Iterate through vertices and build half-edges
for (size_t j = 0; j < FACE.vertexIndices.size(); ++j)
for (size_t j = 0; j < face.vertexIndices.size(); ++j)
{
const int32_t TAIL = FACE.vertexIndices[j];
const int32_t HEAD = FACE.vertexIndices[(j + 1) % FACE.vertexIndices.size()];
const int32_t TAIL = face.vertexIndices[j].index;
const int32_t HEAD = face.vertexIndices[(j + 1) % face.vertexIndices.size()].index;
const uint64_t NEW_EDGE_ID = BUILD_UINT64_FROM_UINT32S(TAIL, HEAD);
const uint64_t TWIN_EDGE_ID = BUILD_UINT64_FROM_UINT32S(HEAD, TAIL);
@ -197,6 +148,9 @@ namespace SHADE
// Set edge index of the newly inserted edge as the size of the map - 1
// Since it is an unordered map, it will just be at the back
newHalfEdge.edgeIndex = static_cast<int32_t>(edgeMap.size()) - 1;
// Map vertex to this edge index
face.vertexIndices[j].edgeIndex = newHalfEdge.edgeIndex;
}
// Find twin edge if one exists
@ -217,6 +171,12 @@ namespace SHADE
// At this point, no duplicates should be in the map and all edges should be linked.
for (auto& halfEdge : edgeMap | std::views::values)
halfEdges.emplace_back(halfEdge);
// Sort based on edge indices
std::ranges::sort(halfEdges.begin(), halfEdges.end(), [](const HalfEdge& lhs, const HalfEdge& rhs)
{
return lhs.edgeIndex < rhs.edgeIndex;
});
}
} // namespace SHADE

53
SHADE_Engine/src/Physics/Collision/CollisionShapes/SHHalfEdgeStructure.h
View File

@ -32,6 +32,10 @@ namespace SHADE
/* Type Definitions */
/*---------------------------------------------------------------------------------*/
/**
* @brief
* Encapsulates the data half edge of a face on a polyhedron.
*/
struct HalfEdge
{
/*-------------------------------------------------------------------------------*/
@ -40,36 +44,35 @@ namespace SHADE
//Head and tail forms the edge.
//Head <----- Tail
int32_t tailVertexIndex;
int32_t tailVertexIndex = -1;
// Head is also tail of the next edge.
int32_t headVertexIndex;
int32_t headVertexIndex = -1;
int32_t edgeIndex;
int32_t edgeIndex = -1;
// Other half of the edge on a different face.
// Important for extrapolating face normals.
int32_t twinEdgeIndex;
int32_t twinEdgeIndex = -1;
// Adjacent face of this edge.
int32_t faceIndex;
/*-------------------------------------------------------------------------------*/
/* Constructors & Destructor */
/*-------------------------------------------------------------------------------*/
HalfEdge () noexcept;
HalfEdge (const HalfEdge& rhs) noexcept;
HalfEdge (HalfEdge&& rhs) noexcept;
~HalfEdge () noexcept = default;
/*-------------------------------------------------------------------------------*/
/* Operator Overloads */
/*-------------------------------------------------------------------------------*/
HalfEdge& operator= (const HalfEdge& rhs) noexcept;
HalfEdge& operator= (HalfEdge&& rhs) noexcept;
int32_t faceIndex = -1;
};
struct Vertex
{
public:
/*-------------------------------------------------------------------------------*/
/* Data Members */
/*-------------------------------------------------------------------------------*/
int32_t index = -1;
int32_t edgeIndex = -1; // the half-edge that this vertex is a tail of.
};
/**
* @brief
* Encapsulates the data of a face on a polyhedron.
*/
struct Face
{
public:
@ -77,10 +80,8 @@ namespace SHADE
/* Data Members */
/*-------------------------------------------------------------------------------*/
// TODO: Store face offset
SHVec3 normal;
std::vector<int32_t> vertexIndices; // Must be in CCW order
std::vector<Vertex> vertexIndices; // Must be in CCW order
/*-------------------------------------------------------------------------------*/
/* Constructors & Destructor */
@ -134,10 +135,6 @@ namespace SHADE
/* Data Members */
/*---------------------------------------------------------------------------------*/
float radius = 0.2f; // Default Radius is 2 cm
// Store the faces and half-edges
std::vector<Face> faces;
std::vector<HalfEdge> halfEdges;

16
SHADE_Engine/src/Physics/Collision/Narrowphase/SHCollision.h
View File

@ -67,10 +67,26 @@ namespace SHADE
[[nodiscard]] static bool ConvexVsConvex (SHManifold& manifold, const SHCollisionShape& A, const SHCollisionShape& B) noexcept;
private:
/*---------------------------------------------------------------------------------*/
/* Type Definitions */
/*---------------------------------------------------------------------------------*/
struct FaceQuery
{
bool colliding = false;
int32_t closestFace = -1;
float bestDistance = std::numeric_limits<float>::lowest();
};
/*---------------------------------------------------------------------------------*/
/* Member Functions */
/*---------------------------------------------------------------------------------*/
// Sphere VS Convex
static FaceQuery findClosestFace (const SHSphereCollisionShape& sphere, const SHConvexPolyhedronCollisionShape& polyhedron) noexcept;
static int32_t findClosestPoint (const SHSphereCollisionShape& sphere, const SHConvexPolyhedronCollisionShape& polyhedron, int32_t faceIndex) noexcept;
static bool isMinkowskiFace(const SHVec3& a, const SHVec3& b, const SHVec3& c, const SHVec3& d) noexcept;
// TODO: buildMinkowskiFace, queryEdgeDirection, distanceBetweenTwoEdges,

391
SHADE_Engine/src/Physics/Collision/Narrowphase/SHSphereVsConvex.cpp
View File

@ -19,16 +19,6 @@
#include "Physics/Collision/CollisionShapes/SHCollisionShape.h"
#include "Physics/Collision/CollisionShapes/SHBoxCollisionShape.h"
// When testing against convex polyhedrons, we do not care so much as whether it is a box
// or something else. We only need the vertices to build half edge structures for use
// with a gauss map. Regardless, we still cast it to the type just to get vertices
// since spheres and capsules do not implement the same method.
// I did consider having another base class that encapsulates methods that convex polyhedrons
// would implement, but for the sake of my sanity, I won't do that.
// TODO
namespace SHADE
{
/*-----------------------------------------------------------------------------------*/
@ -37,6 +27,21 @@ namespace SHADE
bool SHCollision::SphereVsConvex(const SHCollisionShape& A, const SHCollisionShape& B) noexcept
{
const SHSphereCollisionShape& SPHERE = dynamic_cast<const SHSphereCollisionShape&>(A);
const SHConvexPolyhedronCollisionShape& POLYHEDRON = dynamic_cast<const SHConvexPolyhedronCollisionShape&>(B);
const SHVec3 CENTER = SPHERE.GetCenter();
const float RADIUS = SPHERE.GetWorldRadius();
const SHHalfEdgeStructure* HALF_EDGE_STRUCTURE = POLYHEDRON.GetHalfEdgeStructure();
const FaceQuery FACE_QUERY = findClosestFace(SPHERE, POLYHEDRON);
if (!FACE_QUERY.colliding)
return false;
if (FACE_QUERY.bestDistance < SHMath::EPSILON)
return true;
return false;
}
@ -49,19 +54,197 @@ namespace SHADE
{
// Convert to underlying types
// For the convex, we only need the convex polyhedron shape since the get vertex is pure virtual.
const SHSphereCollisionShape& SPHERE = dynamic_cast<const SHSphereCollisionShape&>(A);
const SHConvexPolyhedronCollisionShape& CONVEX = dynamic_cast<const SHConvexPolyhedronCollisionShape&>(B);
const SHSphereCollisionShape& SPHERE = dynamic_cast<const SHSphereCollisionShape&>(A);
const SHConvexPolyhedronCollisionShape& POLYHEDRON = dynamic_cast<const SHConvexPolyhedronCollisionShape&>(B);
const SHVec3 CENTER = SPHERE.GetCenter();
const float RADIUS = SPHERE.GetWorldRadius();
const SHHalfEdgeStructure* HALF_EDGE_STRUCTURE = POLYHEDRON.GetHalfEdgeStructure();
const FaceQuery FACE_QUERY = findClosestFace(SPHERE, POLYHEDRON);
if (!FACE_QUERY.colliding)
return false;
uint32_t numContacts = 0;
const float PENETRATION = RADIUS - FACE_QUERY.bestDistance;
SHContact contact;
contact.featurePair.key = 0;
// Check if center is inside polyhedron (below the face)
if (FACE_QUERY.bestDistance < SHMath::EPSILON)
{
manifold.normal = -POLYHEDRON.GetNormal(FACE_QUERY.closestFace);
contact.penetration = PENETRATION;
contact.position = SPHERE.GetCenter();
manifold.contacts[numContacts++] = contact;
manifold.numContacts = numContacts;
return true;
}
// Find closest face of polygon to circle
const int32_t CLOSEST_POINT = findClosestPoint(SPHERE, POLYHEDRON, FACE_QUERY.closestFace);
int32_t closestFaceIndex = -1;
int32_t closestPointIndex = -1;
float bestDistance = std::numeric_limits<float>::lowest();
const SHHalfEdgeStructure::Face& FACE = POLYHEDRON.GetHalfEdgeStructure()->GetFace(FACE_QUERY.closestFace);
const SHHalfEdgeStructure* HALF_EDGE_STRUCTURE = CONVEX.GetHalfEdgeStructure();
const SHVec3& FACE_NORMAL = POLYHEDRON.GetNormal(FACE_QUERY.closestFace);
const int32_t NUM_VERTICES = static_cast<int32_t>(FACE.vertexIndices.size());
// Check against voronoi regions of the face to determine the type of the intersection test
// We have 3 voronoi regions to check: cp -> prev, cp -> next and cp -> center
// If none of these are true, the sphere is above the face but not separating
/*
* | 2
* _ _ _ _ _ _ | _ _ _
* / /
* | / regionD | / regionA
* |/ _ _ _ _ _|/ _ _ _
* 3/ regionB /1
* / / regionC
*
*/
const SHVec3 P1 = POLYHEDRON.GetVertex(FACE.vertexIndices[CLOSEST_POINT].index);
const SHVec3 P1_TO_CENTER = CENTER - P1;
// To be inside either region A or B, 2 conditions must be satisfied
// 1. Same side as tangent
// 2. Same side as adjacent normal
// Check in regions A
{
const int32_t P2_INDEX = (CLOSEST_POINT + 1) % NUM_VERTICES;
const SHVec3 P2 = POLYHEDRON.GetVertex(FACE.vertexIndices[P2_INDEX].index);
const SHVec3 TANGENT = SHVec3::Normalise(P2 - P1);
float projection = SHVec3::Dot(P1_TO_CENTER, TANGENT);
if (projection >= 0.0f)
{
// Find closest point
const SHVec3 CP = P1 + projection * TANGENT;
// Check 2nd condition
// Get adjacent normal from twin half edge
const int32_t EDGE_INDEX = FACE.vertexIndices[CLOSEST_POINT].edgeIndex;
const int32_t TWIN_EDGE = HALF_EDGE_STRUCTURE->GetHalfEdge(EDGE_INDEX).twinEdgeIndex;
const int32_t ADJ_FACE = HALF_EDGE_STRUCTURE->GetHalfEdge(TWIN_EDGE).faceIndex;
const SHVec3& ADJ_NORMAL = POLYHEDRON.GetNormal(ADJ_FACE);
projection = SHVec3::Dot(P1_TO_CENTER, ADJ_NORMAL);
if (projection >= 0.0f)
{
// Must be smaller than radius
if (projection >= RADIUS)
return false;
const SHVec3 CP_TO_CENTER = CENTER - CP;
manifold.normal = -SHVec3::Normalise(CP_TO_CENTER);
contact.penetration = RADIUS - SHVec3::Dot(CP_TO_CENTER, -manifold.normal);
contact.position = CP;
manifold.contacts[numContacts++] = contact;
manifold.numContacts = numContacts;
return true;
}
}
}
// Check in region B
{
const int32_t P3_INDEX = CLOSEST_POINT == 0 ? NUM_VERTICES - 1 : CLOSEST_POINT - 1;
const SHVec3 P3 = POLYHEDRON.GetVertex(FACE.vertexIndices[P3_INDEX].index);
const SHVec3 TANGENT = SHVec3::Normalise(P3 - P1);
float projection = SHVec3::Dot(P1_TO_CENTER, TANGENT);
if (projection >= 0.0f)
{
// Find closest point
const SHVec3 CP = P1 + projection * TANGENT;
// Check 2nd condition
// Get adjacent normal from twin half edge
const int32_t EDGE_INDEX = FACE.vertexIndices[P3_INDEX].edgeIndex;
const int32_t TWIN_EDGE = HALF_EDGE_STRUCTURE->GetHalfEdge(EDGE_INDEX).twinEdgeIndex;
const int32_t ADJ_FACE = HALF_EDGE_STRUCTURE->GetHalfEdge(TWIN_EDGE).faceIndex;
const SHVec3& ADJ_NORMAL = POLYHEDRON.GetNormal(ADJ_FACE);
projection = SHVec3::Dot(P1_TO_CENTER, ADJ_NORMAL);
if (projection >= 0.0f)
{
// Must be smaller than radius
if (projection >= RADIUS)
return false;
const SHVec3 CP_TO_CENTER = CENTER - CP;
manifold.normal = -SHVec3::Normalise(CP_TO_CENTER);
contact.penetration = RADIUS - SHVec3::Dot(CP_TO_CENTER, -manifold.normal);
contact.position = CP;
manifold.contacts[numContacts++] = contact;
manifold.numContacts = numContacts;
return true;
}
}
}
// Either region C or D. Take whichever depth is smaller
const float C_PENETRATION = RADIUS - P1_TO_CENTER.Length();
if (std::fabs(C_PENETRATION) < RADIUS && std::fabs(C_PENETRATION) < PENETRATION)
{
manifold.normal = -SHVec3::Normalise(P1_TO_CENTER);
contact.penetration = C_PENETRATION;
contact.position = P1;
}
else
{
manifold.normal = -FACE_NORMAL;
contact.penetration = PENETRATION;
contact.position = CENTER - FACE_NORMAL * RADIUS;
}
manifold.contacts[numContacts++] = contact;
manifold.numContacts = numContacts;
return true;
}
bool SHCollision::ConvexVsSphere(SHManifold& manifold, const SHCollisionShape& A, const SHCollisionShape& B) noexcept
{
return SphereVsConvex(manifold, B, A);
}
/*-----------------------------------------------------------------------------------*/
/* Private Member Functions Definitions */
/*-----------------------------------------------------------------------------------*/
SHCollision::FaceQuery SHCollision::findClosestFace(const SHSphereCollisionShape& sphere, const SHConvexPolyhedronCollisionShape& polyhedron) noexcept
{
FaceQuery faceQuery;
const SHVec3 CENTER = sphere.GetCenter();
const float RADIUS = sphere.GetWorldRadius();
const SHHalfEdgeStructure* HALF_EDGE_STRUCTURE = polyhedron.GetHalfEdgeStructure();
/*
* Test against each face.
@ -76,8 +259,8 @@ namespace SHADE
// Build plane equation
const SHVec3 POINT = CONVEX.GetVertex(FACE.vertexIndices[0]); // use the first vertex to build a plane
const SHVec3& NORMAL = CONVEX.GetNormal(i);
const SHVec3 POINT = polyhedron.GetVertex(FACE.vertexIndices[0].index); // use the first vertex to build a plane
const SHVec3& NORMAL = polyhedron.GetNormal(i);
const float D = -SHVec3::Dot(NORMAL, POINT);
// Find signed distance of center to plane
@ -87,153 +270,47 @@ namespace SHADE
// If face is facing away from center, signed dist is negative.
// Therefore signed distance is only positive when sphere is in front of the face.
if (SIGNED_DIST > RADIUS)
return false;
return faceQuery;
if (SIGNED_DIST > bestDistance)
if (SIGNED_DIST > faceQuery.bestDistance)
{
bestDistance = SIGNED_DIST;
closestFaceIndex = i;
faceQuery.bestDistance = SIGNED_DIST;
faceQuery.closestFace = i;
}
}
uint32_t numContacts = 0;
const float PENETRATION = RADIUS - bestDistance;
// Check if center is inside polyhedron (below the face)
if (bestDistance < SHMath::EPSILON)
{
manifold.normal = -CONVEX.GetNormal(closestFaceIndex);
SHContact newContact;
newContact.penetration = PENETRATION;
newContact.position = SPHERE.GetCenter();
newContact.featurePair.key = 0;
manifold.contacts[numContacts++] = newContact;
manifold.numContacts = numContacts;
return true;
}
// Check against voronoi regions of the face to determine the type of the intersection test
// We have 3 voronoi regions to check: cp -> prev, cp -> next and cp -> center
// If none of these are true, the sphere is above the face but not separating
/*
* | A
* _ _ _ _ _ _ | _ _ _
* / /
* | / | / regionA
* |/ _ _ _ _ _|/ _ _ _
* B/ regionB /C
* / / regionC
*/
const SHHalfEdgeStructure::Face& FACE = HALF_EDGE_STRUCTURE->GetFace(closestFaceIndex);
const SHVec3& NORMAL = CONVEX.GetNormal(closestFaceIndex);
const int32_t NUM_VERTICES_ON_FACE = static_cast<int32_t>(FACE.vertexIndices.size());
// Find closest point on face
closestPointIndex = 0;
float smallestDist = SHVec3::Dot(CENTER - CONVEX.GetVertex(FACE.vertexIndices[0]), NORMAL);
for (int32_t i = 1; i < NUM_VERTICES_ON_FACE; ++i)
{
const SHVec3 POINT = CONVEX.GetVertex(FACE.vertexIndices[i]);
const float PROJECTION = SHVec3::Dot(CENTER - POINT, NORMAL);
if (PROJECTION < smallestDist)
closestPointIndex = i;
}
const SHVec3 C = CONVEX.GetVertex(FACE.vertexIndices[closestPointIndex]);
const SHVec3 C_TO_CENTER = SPHERE.GetCenter() - C;
const int32_t INDEX_A = (closestPointIndex + 1) % NUM_VERTICES_ON_FACE;
const int32_t INDEX_B = closestPointIndex == 0 ? NUM_VERTICES_ON_FACE - 1 : closestPointIndex - 1;
const SHVec3 POINTS[2] =
{
CONVEX.GetVertex(FACE.vertexIndices[INDEX_A]) // A
, CONVEX.GetVertex(FACE.vertexIndices[INDEX_B]) // B
};
// To be inside either region A or B, 2 conditions must be satisfied
// 1. Same side as tangent
// 2. Same side as normal from edge to sphere
// Check in regions A & B
for (int i = 0; i < 2; ++i)
{
const SHVec3 TANGENT = SHVec3::Normalise(POINTS[i] - C);
float projection = SHVec3::Dot(C_TO_CENTER, TANGENT);
if (projection >= 0.0f)
{
// Check 2nd condition
// Find closest point
const SHVec3 CP = C + projection * TANGENT;
const SHVec3 CP_TO_CENTER = SHVec3::Normalise(C - CP);
projection = SHVec3::Dot(C_TO_CENTER, CP_TO_CENTER);
if (projection >= 0.0f)
{
// Sphere Within region
manifold.normal = -CP_TO_CENTER;
SHContact newContact;
newContact.penetration = RADIUS - projection;
newContact.position = CP;
newContact.featurePair.key = 0;
manifold.contacts[numContacts++] = newContact;
manifold.numContacts = numContacts;
return true;
}
}
}
// Check region C (closest point)
{
if (C_TO_CENTER.LengthSquared() < RADIUS * RADIUS)
{
manifold.normal = -SHVec3::Normalise(C_TO_CENTER);
SHContact newContact;
newContact.penetration = PENETRATION;
newContact.position = C;
newContact.featurePair.key = 0;
manifold.contacts[numContacts++] = newContact;
manifold.numContacts = numContacts;
return true;
}
}
// Region D
if (PENETRATION <= RADIUS)
{
manifold.normal = -NORMAL;
SHContact newContact;
newContact.penetration = PENETRATION;
newContact.position = SPHERE.GetCenter() - NORMAL * RADIUS;
newContact.featurePair.key = 0;
manifold.contacts[numContacts++] = newContact;
manifold.numContacts = numContacts;
return true;
}
return false;
faceQuery.colliding = true;
return faceQuery;
}
bool SHCollision::ConvexVsSphere(SHManifold& manifold, const SHCollisionShape& A, const SHCollisionShape& B) noexcept
int32_t SHCollision::findClosestPoint(const SHSphereCollisionShape& sphere, const SHConvexPolyhedronCollisionShape& polyhedron, int32_t faceIndex) noexcept
{
return SphereVsConvex(manifold, B, A);
// Find closest point on face
int32_t closestPointIndex = -1;
const SHVec3 CENTER = sphere.GetCenter();
const float RADIUS = sphere.GetWorldRadius();
const SHHalfEdgeStructure* HALF_EDGE_STRUCTURE = polyhedron.GetHalfEdgeStructure();
const SHHalfEdgeStructure::Face& FACE = HALF_EDGE_STRUCTURE->GetFace(faceIndex);
const int32_t NUM_VERITICES = static_cast<int32_t>(FACE.vertexIndices.size());
float smallestDist = std::numeric_limits<float>::max();
for (int32_t i = 0; i < NUM_VERITICES; ++i)
{
const SHVec3 POINT = polyhedron.GetVertex(FACE.vertexIndices[i].index);
const float DIST = SHVec3::DistanceSquared(CENTER, POINT);
if (DIST < smallestDist)
{
smallestDist = DIST;
closestPointIndex = i;
}
}
return closestPointIndex;
}
} // namespace SHADE

4
SHADE_Engine/src/Physics/Collision/SHPhysicsMaterial.h
View File

@ -19,6 +19,10 @@ namespace SHADE
/* Type Definitions */
/*-----------------------------------------------------------------------------------*/
/**
* @brief
* Encapsulates the data of a physics material for physics simulations.
*/
class SH_API SHPhysicsMaterial
{
public: