internal void CreateCollider(Entity rigidbodyEntity)
{
var colliderCount = RigidbodyToColliderMapping.CountValuesForKey(rigidbodyEntity);
if (colliderCount == 0)
{
return;
}
// Single collider doesn't require a compound collider.
if (colliderCount == 1)
{
var foundColliderBlob = RigidbodyToColliderMapping.TryGetFirstValue(rigidbodyEntity, out BlobAssetReference <Collider> colliderBlob, out NativeMultiHashMapIterator <Entity> ignore);
SafetyChecks.IsTrue(foundColliderBlob);
// Add the single collider to the rigidbody entity.
DstEntityManager.AddComponentData(rigidbodyEntity, new PhysicsColliderBlob {
Collider = colliderBlob
});
return;
}
// Multiple colliders required a compound collider.
var childrenArray = new NativeArray <PhysicsCompoundCollider.ColliderBlobInstance>(colliderCount, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var childIndex = 0;
foreach (var colliderBlob in RigidbodyToColliderMapping.GetValuesForKey(rigidbodyEntity))
{
childrenArray[childIndex++] = new PhysicsCompoundCollider.ColliderBlobInstance
{
Collider = colliderBlob,
// NOTE: Right now the relative pose of the collider with respect to the rigidbody is baked into the shape.
// Later, we'll want to remove that and only have its offset (if any) baked into it and use this transform instead.
CompoundFromChild = PhysicsTransform.Identity
};
}
// Create the compound collider.
DstEntityManager.AddComponentData(rigidbodyEntity, new PhysicsColliderBlob {
Collider = PhysicsCompoundCollider.Create(childrenArray)
});
// We've finished with the children blobs and array.
for (var i = 0; i < colliderCount; ++i)
{
childrenArray[i].Collider.Dispose();
}
childrenArray.Dispose();
}
public void MassProperties_BuiltFromChildren_MatchesExpected()
{
void TestCompoundBox(PhysicsTransform transform)
{
// Create a unit box
var boxCollider = PhysicsBoxCollider.Create(new BoxGeometry
{
Size = new float2(1f),
Center = transform.Translation,
Angle = 0f,
BevelRadius = 0.0f
});
// Create a compound of mini boxes, matching the volume of the single box
var miniBox = PhysicsBoxCollider.Create(new BoxGeometry
{
Size = new float2(0.5f),
Center = float2.zero,
Angle = 0f,
BevelRadius = 0.0f
});
const uint UserData = 0xDEADBEEF;
const int ChildrenCount = 4;
var childrenTransforms = new NativeArray <PhysicsTransform>(ChildrenCount, Allocator.Temp, NativeArrayOptions.UninitializedMemory)
{
[0] = new PhysicsTransform(new float2(-0.25f, -0.25f), float2x2.identity),
[1] = new PhysicsTransform(new float2(0.25f, -0.25f), float2x2.identity),
[2] = new PhysicsTransform(new float2(0.25f, 0.25f), float2x2.identity),
[3] = new PhysicsTransform(new float2(-0.25f, 0.25f), float2x2.identity),
};
var children = new NativeArray <PhysicsCompoundCollider.ColliderBlobInstance>(ChildrenCount, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
for (var i = 0; i < ChildrenCount; ++i)
{
children[i] = new PhysicsCompoundCollider.ColliderBlobInstance
{
Collider = miniBox,
CompoundFromChild = PhysicsMath.mul(transform, childrenTransforms[i])
};
}
var colliderBlob = PhysicsCompoundCollider.Create(children, UserData);
childrenTransforms.Dispose();
children.Dispose();
ref var collider = ref colliderBlob.GetColliderRef <PhysicsCompoundCollider>();
Assert.AreEqual(ColliderType.Compound, collider.ColliderType);
Assert.AreEqual(CollisionType.Composite, collider.CollisionType);
Assert.AreEqual(UserData, collider.UserData);
var boxMassProperties = boxCollider.Value.MassProperties;
var compoundMassProperties = colliderBlob.Value.MassProperties;
Assert.AreEqual(boxMassProperties.Area, compoundMassProperties.Area, 1e-3f, "Area incorrect.");
Assert.AreEqual(boxMassProperties.AngularExpansionFactor, compoundMassProperties.AngularExpansionFactor, 1e-3f, "AngularExpansionFactor incorrect.");
PhysicsAssert.AreEqual(boxMassProperties.MassDistribution.LocalCenterOfMass, compoundMassProperties.MassDistribution.LocalCenterOfMass, 1e-3f, "LocalCenterOfMass incorrect.");
Assert.AreEqual(boxMassProperties.MassDistribution.InverseInertia, compoundMassProperties.MassDistribution.InverseInertia, 1e-3f, "InverseInertia incorrect.");
boxCollider.Dispose();
colliderBlob.Dispose();
}