engine/dep/include/reactphysics3d/collision/shapes/TriangleShape.h

382 lines
17 KiB
C++

/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com *
* Copyright (c) 2010-2022 Daniel Chappuis *
*********************************************************************************
* *
* This software is provided 'as-is', without any express or implied warranty. *
* In no event will the authors be held liable for any damages arising from the *
* use of this software. *
* *
* Permission is granted to anyone to use this software for any purpose, *
* including commercial applications, and to alter it and redistribute it *
* freely, subject to the following restrictions: *
* *
* 1. The origin of this software must not be misrepresented; you must not claim *
* that you wrote the original software. If you use this software in a *
* product, an acknowledgment in the product documentation would be *
* appreciated but is not required. *
* *
* 2. Altered source versions must be plainly marked as such, and must not be *
* misrepresented as being the original software. *
* *
* 3. This notice may not be removed or altered from any source distribution. *
* *
********************************************************************************/
#ifndef REACTPHYSICS3D_TRIANGLE_SHAPE_H
#define REACTPHYSICS3D_TRIANGLE_SHAPE_H
// Libraries
#include <reactphysics3d/mathematics/mathematics.h>
#include <reactphysics3d/collision/shapes/ConvexPolyhedronShape.h>
/// ReactPhysics3D namespace
namespace reactphysics3d {
// Forward declarations
class PhysicsCommon;
/// Raycast test side for the triangle
enum class TriangleRaycastSide {
/// Raycast against front triangle
FRONT,
/// Raycast against back triangle
BACK,
/// Raycast against front and back triangle
FRONT_AND_BACK
};
// Class TriangleShape
/**
* This class represents a triangle collision shape that is centered
* at the origin and defined three points. A user cannot instanciate
* an object of this class. This class is for internal use only. Instances
* of this class are created when the user creates an HeightFieldShape and
* a ConcaveMeshShape
*/
class TriangleShape : public ConvexPolyhedronShape {
protected:
// -------------------- Attribute -------------------- //
/// Three points of the triangle
Vector3 mPoints[3];
/// Normal of the triangle
Vector3 mNormal;
/// Three vertices normals for smooth collision with triangle mesh
Vector3 mVerticesNormals[3];
/// Raycast test type for the triangle (front, back, front-back)
TriangleRaycastSide mRaycastTestType;
/// Reference to triangle half-edge structure
HalfEdgeStructure& mTriangleHalfEdgeStructure;
// -------------------- Methods -------------------- //
/// Return a local support point in a given direction without the object margin
virtual Vector3 getLocalSupportPointWithoutMargin(const Vector3& direction) const override;
/// Get a smooth contact normal for collision for a triangle of the mesh
Vector3 computeSmoothLocalContactNormalForTriangle(const Vector3& localContactPoint) const;
/// Return true if a point is inside the collider
virtual bool testPointInside(const Vector3& localPoint, Collider* collider) const override;
/// Raycast method with feedback information
virtual bool raycast(const Ray& ray, RaycastInfo& raycastInfo, Collider* collider, MemoryAllocator& allocator) const override;
/// Return the number of bytes used by the collision shape
virtual size_t getSizeInBytes() const override;
/// Generate the id of the shape (used for temporal coherence)
void generateId();
// -------------------- Methods -------------------- //
/// This method implements the technique described in Game Physics Pearl book
void computeSmoothMeshContact(Vector3 localContactPointTriangle, const Transform& triangleShapeToWorldTransform,
const Transform& worldToOtherShapeTransform, decimal penetrationDepth, bool isTriangleShape1,
Vector3& outNewLocalContactPointOtherShape, Vector3& outSmoothWorldContactTriangleNormal) const;
/// Constructor
TriangleShape(const Vector3* vertices, const Vector3* verticesNormals, uint32 shapeId, HalfEdgeStructure& triangleHalfEdgeStructure,
MemoryAllocator& allocator);
/// Constructor
TriangleShape(const Vector3* vertices, uint32 shapeId, HalfEdgeStructure& triangleHalfEdgeStructure, MemoryAllocator& allocator);
/// Destructor
virtual ~TriangleShape() override = default;
public:
// -------------------- Methods -------------------- //
/// Deleted copy-constructor
TriangleShape(const TriangleShape& shape) = delete;
/// Deleted assignment operator
TriangleShape& operator=(const TriangleShape& shape) = delete;
/// Return the local bounds of the shape in x, y and z directions.
virtual void getLocalBounds(Vector3& min, Vector3& max) const override;
/// Return the local inertia tensor of the collision shape
virtual Vector3 getLocalInertiaTensor(decimal mass) const override;
/// Update the AABB of a body using its collision shape
virtual void computeAABB(AABB& aabb, const Transform& transform) const override;
/// Return the raycast test type (front, back, front-back)
TriangleRaycastSide getRaycastTestType() const;
// Set the raycast test type (front, back, front-back)
void setRaycastTestType(TriangleRaycastSide testType);
/// Return the number of faces of the polyhedron
virtual uint32 getNbFaces() const override;
/// Return a given face of the polyhedron
virtual const HalfEdgeStructure::Face& getFace(uint32 faceIndex) const override;
/// Return the number of vertices of the polyhedron
virtual uint32 getNbVertices() const override;
/// Return a given vertex of the polyhedron
virtual const HalfEdgeStructure::Vertex& getVertex(uint32 vertexIndex) const override;
/// Return the position of a given vertex
virtual Vector3 getVertexPosition(uint32 vertexIndex) const override;
/// Return the normal vector of a given face of the polyhedron
virtual Vector3 getFaceNormal(uint32 faceIndex) const override;
/// Return the number of half-edges of the polyhedron
virtual uint32 getNbHalfEdges() const override;
/// Return a given half-edge of the polyhedron
virtual const HalfEdgeStructure::Edge& getHalfEdge(uint32 edgeIndex) const override;
/// Return the centroid of the polyhedron
virtual Vector3 getCentroid() const override;
/// Compute and return the volume of the collision shape
virtual decimal getVolume() const override;
/// This method compute the smooth mesh contact with a triangle in case one of the two collision shapes is a triangle. The idea in this case is to use a smooth vertex normal of the triangle mesh
static void computeSmoothTriangleMeshContact(const CollisionShape* shape1, const CollisionShape* shape2,
Vector3& localContactPointShape1, Vector3& localContactPointShape2,
const Transform& shape1ToWorld, const Transform& shape2ToWorld,
decimal penetrationDepth, Vector3& outSmoothVertexNormal);
/// Return the string representation of the shape
virtual std::string to_string() const override;
// ---------- Friendship ---------- //
friend class ConcaveMeshRaycastCallback;
friend class TriangleOverlapCallback;
friend class MiddlePhaseTriangleCallback;
friend class HeightFieldShape;
friend class CollisionDetectionSystem;
};
// Return the number of bytes used by the collision shape
RP3D_FORCE_INLINE size_t TriangleShape::getSizeInBytes() const {
return sizeof(TriangleShape);
}
// Return a local support point in a given direction without the object margin
RP3D_FORCE_INLINE Vector3 TriangleShape::getLocalSupportPointWithoutMargin(const Vector3& direction) const {
Vector3 dotProducts(direction.dot(mPoints[0]), direction.dot(mPoints[1]), direction.dot(mPoints[2]));
return mPoints[dotProducts.getMaxAxis()];
}
// Return the local bounds of the shape in x, y and z directions.
// This method is used to compute the AABB of the box
/**
* @param min The minimum bounds of the shape in local-space coordinates
* @param max The maximum bounds of the shape in local-space coordinates
*/
RP3D_FORCE_INLINE void TriangleShape::getLocalBounds(Vector3& min, Vector3& max) const {
const Vector3 xAxis(mPoints[0].x, mPoints[1].x, mPoints[2].x);
const Vector3 yAxis(mPoints[0].y, mPoints[1].y, mPoints[2].y);
const Vector3 zAxis(mPoints[0].z, mPoints[1].z, mPoints[2].z);
min.setAllValues(xAxis.getMinValue(), yAxis.getMinValue(), zAxis.getMinValue());
max.setAllValues(xAxis.getMaxValue(), yAxis.getMaxValue(), zAxis.getMaxValue());
min -= Vector3(mMargin, mMargin, mMargin);
max += Vector3(mMargin, mMargin, mMargin);
}
// Return the local inertia tensor of the triangle shape
/**
* @param[out] tensor The 3x3 inertia tensor matrix of the shape in local-space
* coordinates
* @param mass Mass to use to compute the inertia tensor of the collision shape
*/
RP3D_FORCE_INLINE Vector3 TriangleShape::getLocalInertiaTensor(decimal /*mass*/) const {
return Vector3(0, 0, 0);
}
// Return true if a point is inside the collision shape
RP3D_FORCE_INLINE bool TriangleShape::testPointInside(const Vector3& /*localPoint*/, Collider* /*collider*/) const {
return false;
}
// Return the number of faces of the polyhedron
RP3D_FORCE_INLINE uint32 TriangleShape::getNbFaces() const {
return 2;
}
// Return the number of vertices of the polyhedron
RP3D_FORCE_INLINE uint32 TriangleShape::getNbVertices() const {
return 3;
}
// Return a given vertex of the polyhedron
RP3D_FORCE_INLINE const HalfEdgeStructure::Vertex& TriangleShape::getVertex(uint32 vertexIndex) const {
assert(vertexIndex < 3);
return mTriangleHalfEdgeStructure.getVertex(vertexIndex);
}
// Return the position of a given vertex
RP3D_FORCE_INLINE Vector3 TriangleShape::getVertexPosition(uint32 vertexIndex) const {
assert(vertexIndex < 3);
return mPoints[vertexIndex];
}
// Return the normal vector of a given face of the polyhedron
RP3D_FORCE_INLINE Vector3 TriangleShape::getFaceNormal(uint32 faceIndex) const {
assert(faceIndex < 2);
assert(mNormal.length() > decimal(0.0));
return faceIndex == 0 ? mNormal : -mNormal;
}
// Return the centroid of the box
RP3D_FORCE_INLINE Vector3 TriangleShape::getCentroid() const {
return (mPoints[0] + mPoints[1] + mPoints[2]) / decimal(3.0);
}
// Return the number of half-edges of the polyhedron
RP3D_FORCE_INLINE uint32 TriangleShape::getNbHalfEdges() const {
return 6;
}
// Return the raycast test type (front, back, front-back)
RP3D_FORCE_INLINE TriangleRaycastSide TriangleShape::getRaycastTestType() const {
return mRaycastTestType;
}
// Set the raycast test type (front, back, front-back)
/**
* @param testType Raycast test type for the triangle (front, back, front-back)
*/
RP3D_FORCE_INLINE void TriangleShape::setRaycastTestType(TriangleRaycastSide testType) {
mRaycastTestType = testType;
}
// Return the string representation of the shape
RP3D_FORCE_INLINE std::string TriangleShape::to_string() const {
return "TriangleShape{v1=" + mPoints[0].to_string() + ", v2=" + mPoints[1].to_string() + "," +
"v3=" + mPoints[2].to_string() + "}";
}
// Compute and return the volume of the collision shape
RP3D_FORCE_INLINE decimal TriangleShape::getVolume() const {
return decimal(0.0);
}
// Get a smooth contact normal for collision for a triangle of the mesh
/// This is used to avoid the internal edges issue that occurs when a shape is colliding with
/// several triangles of a concave mesh. If the shape collide with an edge of the triangle for instance,
/// the computed contact normal from this triangle edge is not necessarily in the direction of the surface
/// normal of the mesh at this point. The idea to solve this problem is to use the real (smooth) surface
/// normal of the mesh at this point as the contact normal. This technique is described in the chapter 5
/// of the Game Physics Pearl book by Gino van der Bergen and Dirk Gregorius. The vertices normals of the
/// mesh are either provided by the user or precomputed if the user did not provide them. Note that we only
/// use the interpolated normal if the contact point is on an edge of the triangle. If the contact is in the
/// middle of the triangle, we return the true triangle normal.
RP3D_FORCE_INLINE Vector3 TriangleShape::computeSmoothLocalContactNormalForTriangle(const Vector3& localContactPoint) const {
assert(mNormal.length() > decimal(0.0));
// Compute the barycentric coordinates of the point in the triangle
decimal u, v, w;
computeBarycentricCoordinatesInTriangle(mPoints[0], mPoints[1], mPoints[2], localContactPoint, u, v, w);
// If the contact is in the middle of the triangle face (not on the edges)
if (u > MACHINE_EPSILON && v > MACHINE_EPSILON && w > MACHINE_EPSILON) {
// We return the true triangle face normal (not the interpolated one)
return mNormal;
}
// We compute the contact normal as the barycentric interpolation of the three vertices normals
const Vector3 interpolatedNormal = u * mVerticesNormals[0] + v * mVerticesNormals[1] + w * mVerticesNormals[2];
// If the interpolated normal is degenerated
if (interpolatedNormal.lengthSquare() < MACHINE_EPSILON) {
// Return the original normal
return mNormal;
}
return interpolatedNormal.getUnit();
}
// This method compute the smooth mesh contact with a triangle in case one of the two collision
// shapes is a triangle. The idea in this case is to use a smooth vertex normal of the triangle mesh
// at the contact point instead of the triangle normal to avoid the internal edge collision issue.
// This method will return the new smooth world contact
// normal of the triangle and the the local contact point on the other shape.
RP3D_FORCE_INLINE void TriangleShape::computeSmoothTriangleMeshContact(const CollisionShape* shape1, const CollisionShape* shape2,
Vector3& localContactPointShape1, Vector3& localContactPointShape2,
const Transform& shape1ToWorld, const Transform& shape2ToWorld,
decimal penetrationDepth, Vector3& outSmoothVertexNormal) {
assert(shape1->getName() != CollisionShapeName::TRIANGLE || shape2->getName() != CollisionShapeName::TRIANGLE);
// If one the shape is a triangle
bool isShape1Triangle = shape1->getName() == CollisionShapeName::TRIANGLE;
if (isShape1Triangle || shape2->getName() == CollisionShapeName::TRIANGLE) {
const TriangleShape* triangleShape = isShape1Triangle ? static_cast<const TriangleShape*>(shape1):
static_cast<const TriangleShape*>(shape2);
// Compute the smooth triangle mesh contact normal and recompute the local contact point on the other shape
triangleShape->computeSmoothMeshContact(isShape1Triangle ? localContactPointShape1 : localContactPointShape2,
isShape1Triangle ? shape1ToWorld : shape2ToWorld,
isShape1Triangle ? shape2ToWorld.getInverse() : shape1ToWorld.getInverse(),
penetrationDepth, isShape1Triangle,
isShape1Triangle ? localContactPointShape2 : localContactPointShape1,
outSmoothVertexNormal);
}
}
// Return a given face of the polyhedron
RP3D_FORCE_INLINE const HalfEdgeStructure::Face& TriangleShape::getFace(uint32 faceIndex) const {
assert(faceIndex < 2);
return mTriangleHalfEdgeStructure.getFace(faceIndex);
}
// Return a given half-edge of the polyhedron
RP3D_FORCE_INLINE const HalfEdgeStructure::Edge& TriangleShape::getHalfEdge(uint32 edgeIndex) const {
assert(edgeIndex < getNbHalfEdges());
return mTriangleHalfEdgeStructure.getHalfEdge(edgeIndex);
}
}
#endif