private static List <ScanResultLOD> GetCenterPointList(
Transform transform,
GameObjectShape shape)
{
// Single ScanResultLOD for lowest LOD.
var result = ScanResultLOD.CreateList(1);
Matrix4x4 matrix = transform.worldToLocalMatrix;
bool flatten = shape.Flatten;
foreach (Volume vol in s_Volumes)
{
Vector3 localPoint = matrix.MultiplyPoint3x4(vol.Bounds.center);
if (flatten)
{
localPoint.y = 0;
}
result[0].LocalPoints.Add(localPoint);
}
return(result);
}
/// <summary>
/// Performs a scan over a set of colliders and returns
/// lists of enclosed points for different levels of detail.
/// </summary>
/// <param name="scene"><see cref="PhysicsScene"/> for raycasts and overlap checks</param>
/// <param name="transform"><see cref="DetectableGameObject"/> transform</param>
/// <param name="colliders">List of colliders</param>
/// <param name="shape"><see cref="GameObjectShape"/></param>
/// <param name="result">List of <see cref="ScanResultLOD"/> instances (output)</param>
/// <returns>The highest LOD for the given scan settings and object size</returns>
public static int Scan(
PhysicsScene scene,
Transform transform,
IList <Collider> colliders,
GameObjectShape shape,
out List <ScanResultLOD> result)
{
s_GlobalMaxLOD = 0;
CheckPhysicsBufferSize(colliders);
CreateVolumes(colliders, shape);
result = shape.ScanLOD > 0
? GetLODPointLists(scene, transform, shape)
: GetCenterPointList(transform, shape);
// GlobalMaxLOD corresponds to the result list's
// length unless the 'flatten' option is enabled:
// GlobalMaxLOD = result.Length - 1
//
// If the points are flattened for 2D, the result
// only contains a single point list, because dynamic
// LODs are unnecessary for 2D detection.
// However, GlobalMaxLOD still refers to the number
// of LODs that *would* be used given the current
// Scan LOD without flattening. The reason for this
// is that we need the max LOD value for showing
// the correct inspector settings, even if the scan
// result contains only one point list.
//
// GlobalMaxLOD is also used for clamping the
// Scan LOD setting, because we have a minimum
// length limit when splitting volumes into cells.
// Therefore it's not possible to apply high Scan
// LODs to small colliders/volumes.
return(s_GlobalMaxLOD);
}
private static List <ScanResultLOD> GetLODPointLists(
PhysicsScene scene,
Transform transform,
GameObjectShape shape)
{
SplitVolumesIntoCells(shape.ScanLOD);
int mask = 1 << transform.gameObject.layer;
bool flatten = shape.Flatten;
var result = ScanResultLOD.CreateList(flatten ? 1 : s_GlobalMaxLOD + 1);
foreach (Volume vol in s_Volumes)
{
ToggleActiveColliders(vol);
bool isConcave = vol.IsConcave;
Vector3 cellSize = vol.CellSize;
Vector3Int gridSize = vol.GridSize;
Vector3 offset = vol.Bounds.min + cellSize * 0.5f;
Vector3 boundsCenter = vol.Bounds.center;
float boundsMagnitude = vol.Bounds.size.magnitude;
int nx = gridSize.x - 1;
int ny = gridSize.y - 1;
int nz = gridSize.z - 1;
// Find cells occupied by colliders.
Clear(gridSize);
for (int x = 0; x <= nx; x++)
{
for (int y = 0; y <= ny; y++)
{
for (int z = 0; z <= nz; z++)
{
Vector3 worldPoint = Vector3.Scale(
new Vector3(x, y, z), cellSize) + offset;
bool isInside = isConcave
? IsInsideCollider(
scene, mask, worldPoint, vol.Bounds)
: IsInsideCollider(
scene, mask, worldPoint, vol.Colliders);
s_HollowGrid[x, y, z] = isInside;
s_FilledGrid[x, y, z] = isInside;
}
}
}
// Reduce cell count, hollow out filled grid.
for (int x = 1; x < nx; x++)
{
for (int y = 1; y < ny; y++)
{
for (int z = 1; z < nz; z++)
{
if (s_FilledGrid[x, y, z])
{
s_HollowGrid[x, y, z] &=
!(s_FilledGrid[x - 1, y, z]
& s_FilledGrid[x + 1, y, z]
& s_FilledGrid[x, y - 1, z]
& s_FilledGrid[x, y + 1, z]
& s_FilledGrid[x, y, z - 1]
& s_FilledGrid[x, y, z + 1]);
}
}
}
}
// Downsample cells for generating LODs
// and store points in corresponding groups.
int level = flatten ? 0 : vol.MaxLOD;
float yFlat = transform.position.y;
for (int x = 0; x <= nx; x++)
{
for (int y = 0; y <= ny; y++)
{
for (int z = 0; z <= nz; z++)
{
if (s_HollowGrid[x, y, z])
{
Cell cell = new Cell(level, x, y, z);
Vector3 worldPoint = cell.Scale(cellSize) + offset;
if (flatten)
{
cell.y = 0;
worldPoint.y = yFlat;
}
// Highest LOD.
AddPoint(cell, worldPoint);
for (int i = level; i > 0; i--)
{
cell = cell.Downsample();
AddPoint(cell, worldPoint);
}
}
}
}
}
// Write centroids to result.
Matrix4x4 matrix = transform.worldToLocalMatrix;
float projection = shape.Projection;
bool project = projection > 0;
foreach (var kvp in s_PointGroupsByCell)
{
// KeyValuePair, Key: Cell, Value: PointGroup.
int i = kvp.Key.level;
Vector3 worldPoint = kvp.Value.Centroid;
if (project && i > 0)
{
// Project outward from volume bounds center,
// unless lowest LOD or flattened points -> i == 0.
// NOTE Doesn't work well with compound or concave colliders.
Vector3 normal = (worldPoint - boundsCenter).normalized;
if (scene.Raycast(boundsCenter + normal * boundsMagnitude,
-normal, out RaycastHit hit, boundsMagnitude, mask))
{
worldPoint = Vector3.Lerp(worldPoint, hit.point, projection);
}
}
// World -> local.
result[i].LocalPoints.Add(matrix.MultiplyPoint3x4(worldPoint));
}
}
ToggleActiveColliders();
return(result);
}
private static void CreateVolumes(
IList <Collider> colliders,
GameObjectShape shape)
{
s_Volumes.Clear();
if (shape.Merge)
{
// Merge all.
var volume = new Volume()
{
Colliders = new List <Collider>(colliders)
};
foreach (var collider in colliders)
{
bool isConcave = collider is MeshCollider &&
!((MeshCollider)collider).convex;
volume.IsConcave = volume.IsConcave || isConcave;
volume.Bounds.Encapsulate(collider.bounds);
}
s_Volumes.Add(volume);
}
else
{
var byColliderType = new List <Volume>[]
{
new List <Volume>(), new List <Volume>()
};
foreach (var collider in colliders)
{
bool isConcave = collider is MeshCollider &&
!((MeshCollider)collider).convex;
byColliderType[isConcave ? 1 : 0].Add(new Volume()
{
Colliders = new List <Collider>()
{
collider
},
Bounds = collider.bounds,
IsConcave = isConcave
});
}
// Merge connected by type, don't mix convex and concave.
for (int i = 0; i < 2; i++)
{
var volumes = byColliderType[i];
for (int j = volumes.Count - 1; j > 0; j--)
{
for (int k = j - 1; k > -1; k--)
{
// NOTE Intersects check yields true for colliders
// located side by side, e.g. two box colliders of
// size 1x1x1, sitting at 0/0/0 and 1/1/1 respectively.
if (volumes[j].Bounds.Intersects(volumes[k].Bounds))
{
volumes[j].Bounds.Encapsulate(volumes[k].Bounds);
volumes[j].Colliders.AddRange(volumes[k].Colliders);
volumes.RemoveAt(k);
j--;
}
}
}
s_Volumes.AddRange(volumes);
}
}
}
