public BreslavTextureTransition Update(Camera cam, Transform parentObjectTransform)
{
var baseWeights = ComputeWeightsOfPoints(_samples, cam, parentObjectTransform);
var that = this;
var weights = Enumerable.Range(0, _samples.Count).Select(i =>
{
var oldW = that._lastFrameInfo.Weights[i];
var newW = baseWeights[i];
if (oldW > 0 && newW > 0) // we only consider points that are visible in this and previous frames
{
return(newW);
}
else
{
return(0);
}
}).ToList();
var anyNotZero = weights.Any(c => c > 0);
//Debug.Log(anyNotZero + );
var screenPosOfPoints = _samples.Select(c => cam.WorldToViewportPoint(parentObjectTransform.localToWorldMatrix.MultiplyPoint(c.Position))).Select(c => new Vector2(c.x, c.y)).ToList();
if (!anyNotZero)
{
_lastFrameInfo.Weights = baseWeights;
_lastFrameInfo.SamplePointsScreenPositions = screenPosOfPoints;
return(_lastTransition);
}
var currentCentertoid = screenPosOfPoints.Select((c, i) => c * weights[i]).Aggregate((a, b) => a + b) / weights.Sum();
var currentDeltaPositions = screenPosOfPoints.Select(c => c - currentCentertoid).ToList();
var previousCentertoid = _lastFrameInfo.SamplePointsScreenPositions.Select((c, i) => c * weights[i]).Aggregate((a, b) => a + b) / weights.Sum();
var previousDeltaPositions = _lastFrameInfo.SamplePointsScreenPositions.Select(c => c - previousCentertoid).ToList();
Vector2 z;
float zScaleMultiplier = 0;
if (_configuration.ZComputingMode == BreslavZComputingMode.PaperMode)
{
var left = Enumerable.Range(0, _samples.Count).Select(i =>
new Vector2(
Vector2.Dot(weights[i] * previousDeltaPositions[i], currentDeltaPositions[i]),
VectorUtils.CrossProduct(weights[i] * previousDeltaPositions[i], currentDeltaPositions[i])
)).Aggregate((a, b) => a + b);
var right = Enumerable.Range(0, _samples.Count).Select(i => weights[i] * Math.Pow(previousDeltaPositions[i].magnitude, 2))
.Aggregate((a, b) => a + b);
var _z = left / (float)right;
var s = (1 / _z.magnitude) * Math.Sqrt(
Enumerable.Range(0, _samples.Count).Select(i => weights[i] * Math.Pow(previousDeltaPositions[i].magnitude, 2))
.Aggregate((a, b) => a + b) /
Enumerable.Range(0, _samples.Count).Select(i => weights[i] * Math.Pow(currentDeltaPositions[i].magnitude, 2))
.Aggregate((a, b) => a + b)
);
if (!_configuration.DoRotation)
{
_z = new Vector2(_z[0], 0);
}
zScaleMultiplier = _z.magnitude;
_z *= (float)s;
z = _z;
}
else
{
double so = 0;
double sn = 0;
Vector2 _z = new Vector2(0, 0);
for (int i = 0; i < _samples.Count; i++)
{
if (weights[i] > 0)
{
var m_o = previousDeltaPositions[i];
var m_n = currentDeltaPositions[i];
float m_w = weights[i];
_z += new Vector2((float)Cm2(m_o, m_n), (float)Det(m_o, m_n)) * m_w;
so += m_o.sqrMagnitude * m_w;
sn += m_n.sqrMagnitude * m_w;
}
}
if (_configuration.DoSymmetricScalling)
{
_z = _z.normalized * Mathf.Sqrt((float)(sn / so));
}
else
{
_z /= ((float)so);
}
zScaleMultiplier = _z.magnitude;
z = _z;
if (!_configuration.DoRotation)
{
z = new Vector2(z[0], 0);
}
double EPSILON = 0.00000000001;
if (Math.Abs(so) <= EPSILON || Math.Abs(sn) <= EPSILON || _z.magnitude <= EPSILON)
{
_lastFrameInfo = new BreslavFrameInfo()
{
O = _lastFrameInfo.O,
U = _lastFrameInfo.U,
V = _lastFrameInfo.V,
SamplePointsScreenPositions = screenPosOfPoints,
Weights = baseWeights,
LodInfo = _lastFrameInfo.LodInfo
};
return(_lastTransition);
}
}
var lodInfo = _lastFrameInfo.LodInfo.Clone();
lodInfo.Scale *= zScaleMultiplier;
// interpolation parameter between 2 LOD scales
float st = 0;
var o = currentCentertoid + ComplexMultiplication(_lastFrameInfo.O - previousCentertoid, z);
var u = ComplexMultiplication(_lastFrameInfo.U, z);
var v = ComplexMultiplication(_lastFrameInfo.V, z);
if (_configuration.UseLod)
{
float locScale = lodInfo.Scale;
Preconditions.Assert(locScale > 0, $"LocScale <= 0: {locScale}");
while (locScale >= 2) //Ensuring s is [1,2)
{
locScale /= 2;
}
while (locScale < 1)
{
locScale *= 2;
}
if (locScale < _configuration.Lod_St0)
{
st = 0;
}
else if (locScale > _configuration.Lod_St1)
{
st = 1;
}
else
{
st = (locScale - _configuration.Lod_St0) / (_configuration.Lod_St1 - _configuration.Lod_St0);
}
u = u.normalized * locScale;
v = v.normalized * locScale;
}
_lastFrameInfo = new BreslavFrameInfo()
{
O = o,
U = u,
V = v,
SamplePointsScreenPositions = screenPosOfPoints,
Weights = baseWeights,
LodInfo = lodInfo
};
return(new BreslavTextureTransition()
{
V = v,
O = o,
St = st,
U = u,
LodScale = lodInfo.Scale
});
}