// Tests that the points of a manifold are all coplanar
static unsafe void CheckManifoldFlat(ref ConvexConvexManifoldQueries.Manifold manifold, float3 normal, string failureMessage)
{
float3 point0 = manifold[0].Position + normal * manifold[0].Distance;
float3 point1 = manifold[1].Position + normal * manifold[1].Distance;
for (int i = 2; i < manifold.NumContacts; i++)
{
// Try to calculate a plane from points 0, 1, iNormal
float3 point = manifold[i].Position + normal * manifold[i].Distance;
float3 cross = math.cross(point - point0, point - point1);
if (math.lengthsq(cross) > 1e-6f)
{
// Test that each point in the manifold is on the plane
float3 faceNormal = math.normalize(cross);
float dot = math.dot(point0, faceNormal);
for (int j = 2; j < manifold.NumContacts; j++)
{
float3 testPoint = manifold[j].Position + normal * manifold[j].Distance;
Assert.AreEqual(dot, math.dot(faceNormal, testPoint), tolerance, failureMessage + " contact " + j);
}
break;
}
}
}
public unsafe void ManifoldQueryTest()
{
const uint seed = 0x98765432;
Random rnd = new Random(seed);
int numWorlds = 1000;
uint dbgWorld = 0;
if (dbgWorld > 0)
{
numWorlds = 1;
}
for (int iWorld = 0; iWorld < numWorlds; iWorld++)
{
// Save state to repro this query without doing everything that came before it
if (dbgWorld > 0)
{
rnd.state = dbgWorld;
}
uint worldState = rnd.state;
Physics.PhysicsWorld world = TestUtils.GenerateRandomWorld(ref rnd, rnd.NextInt(1, 20), 3.0f);
// Manifold test
// TODO would be nice if we could change the world collision tolerance
for (int iBodyA = 0; iBodyA < world.NumBodies; iBodyA++)
{
for (int iBodyB = iBodyA + 1; iBodyB < world.NumBodies; iBodyB++)
{
Physics.RigidBody bodyA = world.Bodies[iBodyA];
Physics.RigidBody bodyB = world.Bodies[iBodyB];
if (bodyA.Collider->Type == ColliderType.Mesh && bodyB.Collider->Type == ColliderType.Mesh)
{
continue; // TODO - no mesh-mesh manifold support yet
}
// Build manifolds
BlockStream contacts = new BlockStream(1, 0, Allocator.Temp);
BlockStream.Writer contactWriter = contacts;
contactWriter.BeginForEachIndex(0);
ManifoldQueries.BodyBody(ref world, new BodyIndexPair {
BodyAIndex = iBodyA, BodyBIndex = iBodyB
}, 1.0f, ref contactWriter);
contactWriter.EndForEachIndex();
// Read each manifold
BlockStream.Reader contactReader = contacts;
contactReader.BeginForEachIndex(0);
int manifoldIndex = 0;
while (contactReader.RemainingItemCount > 0)
{
string failureMessage = iWorld + " (" + worldState + ") " + iBodyA + " vs " + iBodyB + " #" + manifoldIndex;
manifoldIndex++;
// Read the manifold header
ContactHeader header = contactReader.Read <ContactHeader>();
ConvexConvexManifoldQueries.Manifold manifold = new ConvexConvexManifoldQueries.Manifold();
manifold.NumContacts = header.NumContacts;
manifold.Normal = header.Normal;
// Get the leaf shapes
ChildCollider leafA, leafB;
{
Collider.GetLeafCollider(bodyA.Collider, bodyA.WorldFromBody, header.ColliderKeys.ColliderKeyA, out leafA);
Collider.GetLeafCollider(bodyB.Collider, bodyB.WorldFromBody, header.ColliderKeys.ColliderKeyB, out leafB);
}
// Read each contact point
int minIndex = 0;
for (int iContact = 0; iContact < header.NumContacts; iContact++)
{
// Read the contact and find the closest
ContactPoint contact = contactReader.Read <ContactPoint>();
manifold[iContact] = contact;
if (contact.Distance < manifold[minIndex].Distance)
{
minIndex = iContact;
}
// Check that the contact point is on or inside the shape
CheckPointOnSurface(ref leafA, contact.Position + manifold.Normal * contact.Distance, failureMessage + " contact " + iContact + " leaf A");
CheckPointOnSurface(ref leafB, contact.Position, failureMessage + " contact " + iContact + " leaf B");
}
// Check the closest point
{
ContactPoint closestPoint = manifold[minIndex];
RigidTransform aFromWorld = math.inverse(leafA.TransformFromChild);
DistanceQueries.Result result = new DistanceQueries.Result
{
PositionOnAinA = math.transform(aFromWorld, closestPoint.Position + manifold.Normal * closestPoint.Distance),
NormalInA = math.mul(aFromWorld.rot, manifold.Normal),
Distance = closestPoint.Distance
};
MTransform aFromB = new MTransform(math.mul(aFromWorld, leafB.TransformFromChild));
float referenceDistance = DistanceQueries.ConvexConvex(leafA.Collider, leafB.Collider, aFromB).Distance;
ValidateDistanceResult(result, ref ((ConvexCollider *)leafA.Collider)->ConvexHull, ref ((ConvexCollider *)leafB.Collider)->ConvexHull, aFromB, referenceDistance, failureMessage + " closest point");
}
// Check that the manifold is flat
CheckManifoldFlat(ref manifold, manifold.Normal, failureMessage + ": non-flat A");
CheckManifoldFlat(ref manifold, float3.zero, failureMessage + ": non-flat B");
}
contacts.Dispose();
}
}
world.Dispose(); // TODO leaking memory if the test fails
}
}
