/// <summary>
/// Returns true if a collider's bounds is within the camera FOV.
/// Utilizes a cache to test if this collider has been seen before and returns current frame's calculated result.
/// </summary>
/// <param name="myCollider">The collider to test</param>
public static bool IsInFOVConeCached(this Camera cam,
Collider myCollider)
{
// if the collider's size is zero, it is not visible. Return false.
if (myCollider.bounds.size == Vector3.zero || myCollider.transform.localScale == Vector3.zero)
{
return(false);
}
Tuple <Collider, Camera> cameraColliderPair = new Tuple <Collider, Camera>(myCollider, cam);
bool result = false;
if (inFOVConeLastCalculatedFrame != Time.frameCount)
{
inFOVConeColliderCache.Clear();
inFOVConeLastCalculatedFrame = Time.frameCount;
}
else if (inFOVConeColliderCache.TryGetValue(cameraColliderPair, out result))
{
return(result);
}
inFOVConeBoundsCornerPoints.Clear();
BoundsExtensions.GetColliderBoundsPoints(myCollider, inFOVConeBoundsCornerPoints, 0);
float xMin = float.MaxValue, yMin = float.MaxValue, zMin = float.MaxValue;
float xMax = float.MinValue, yMax = float.MinValue, zMax = float.MinValue;
for (int i = 0; i < inFOVConeBoundsCornerPoints.Count; i++)
{
var corner = inFOVConeBoundsCornerPoints[i];
if (cam.IsInFOVCone(corner, 0))
{
inFOVConeColliderCache.Add(cameraColliderPair, true);
return(true);
}
xMin = Mathf.Min(xMin, corner.x);
yMin = Mathf.Min(yMin, corner.y);
zMin = Mathf.Min(zMin, corner.z);
xMax = Mathf.Max(xMax, corner.x);
yMax = Mathf.Max(yMax, corner.y);
zMax = Mathf.Max(zMax, corner.z);
}
var cameraPos = cam.transform.position;
result = xMin <= cameraPos.x && cameraPos.x <= xMax &&
yMin <= cameraPos.y && cameraPos.y <= yMax &&
zMin <= cameraPos.z && cameraPos.z <= zMax;
inFOVConeColliderCache.Add(cameraColliderPair, result);
return(result);
}
/// <summary>
/// Returns true if a collider's bounds is within the camera FOV.
/// Utilizes a cache to test if this collider has been seen before and returns current frame's calculated result.
/// NOTE: This is a 'loose' FOV check -- it can return true in cases when the collider is actually not in the FOV
/// because it does an axis-aligned check when testing for large colliders. So, if the axis aligned bounds are in the bounds of the camera, it will return true.
/// </summary>
/// <param name="myCollider">The collider to test</param>
public static bool IsInFOVCached(this Camera cam, Collider myCollider)
{
// if the collider's size is zero, it is not visible. Return false.
if (myCollider.bounds.size == Vector3.zero || myCollider.transform.localScale == Vector3.zero)
{
return(false);
}
Tuple <Collider, Camera> cameraColliderPair = new Tuple <Collider, Camera>(myCollider, cam);
bool result = false;
if (inFOVLastCalculatedFrame != Time.frameCount)
{
inFOVColliderCache.Clear();
inFOVLastCalculatedFrame = Time.frameCount;
}
else if (inFOVColliderCache.TryGetValue(cameraColliderPair, out result))
{
return(result);
}
inFOVBoundsCornerPoints.Clear();
BoundsExtensions.GetColliderBoundsPoints(myCollider, inFOVBoundsCornerPoints, 0);
float xMin = float.MaxValue, yMin = float.MaxValue, zMin = float.MaxValue;
float xMax = float.MinValue, yMax = float.MinValue, zMax = float.MinValue;
for (int i = 0; i < inFOVBoundsCornerPoints.Count; i++)
{
var corner = inFOVBoundsCornerPoints[i];
Vector3 screenPoint = cam.WorldToViewportPoint(corner);
bool isInFOV = screenPoint.z >= 0 && screenPoint.z <= cam.farClipPlane &&
screenPoint.x >= 0 && screenPoint.x <= 1 &&
screenPoint.y >= 0 && screenPoint.y <= 1;
if (isInFOV)
{
inFOVColliderCache.Add(cameraColliderPair, true);
return(true);
}
// if the point is behind the camera, the x and y viewport positions are negated
var zViewport = screenPoint.z;
var xViewport = zViewport >= 0 ? screenPoint.x : -screenPoint.x;
var yViewport = zViewport >= 0 ? screenPoint.y : -screenPoint.y;
xMin = Mathf.Min(xMin, xViewport);
yMin = Mathf.Min(yMin, yViewport);
zMin = Mathf.Min(zMin, zViewport);
xMax = Mathf.Max(xMax, xViewport);
yMax = Mathf.Max(yMax, yViewport);
zMax = Mathf.Max(zMax, zViewport);
}
// Check that collider is visible even if all corners are not visible
// such as when having a large collider
result =
zMax > 0 && // Front of collider is in front of the camera.
zMin < cam.farClipPlane && // Back of collider is not too far away.
xMin < 1 && // Left edge is not too far to the right.
xMax > 0 && // Right edge is not too far to the left.
yMin < 1 && // Bottom edge is not too high.
yMax > 0; // Top edge is not too low.
inFOVColliderCache.Add(cameraColliderPair, result);
return(result);
}
