public static Vector3 BuoyancyForce(float densityOfWater, TriangleInfo triangle)
{
Vector3 buoyancyForce = densityOfWater * Physics.gravity.y * -1 * triangle.height * triangle.area * triangle.normal;
// The vertical component of the hydrostatic forces don't cancel out but the horizontal do
buoyancyForce.x = 0f;
buoyancyForce.z = 0f;
return(buoyancyForce);
}
public static Vector3 PressureDragForce(TriangleInfo triangle, float referenceVelocity, float pdCoefficient1, float pdCoefficient2, float pdFallOffPower, float sdCoefficient1, float sdCoefficient2, float sdFallOffPower)
{
float speed = triangle.velocity.magnitude / referenceVelocity;
float cosine = triangle.cosine;
if (cosine > 0)
{
return(-1 * (pdCoefficient1 * speed + pdCoefficient2 * speed * speed) * triangle.area * Mathf.Pow(cosine, pdFallOffPower) * triangle.normal);
}
else
{
return((sdCoefficient1 * speed + sdCoefficient2 * speed * speed) * triangle.area * Mathf.Pow(-cosine, sdFallOffPower) * triangle.normal);
}
}
private float CuttingAlgorithmHorizontal(VertexInfo top, VertexInfo mid, VertexInfo bottom, int triangleIndex)
{
if (top.height - mid.height < epsilon)
{
int triangleType = (mid.height - bottom.height < epsilon) ? 2 : 1;
TriangleInfo triangle;
if ((top.clockwiseOrder + 1) % 3 == mid.clockwiseOrder)
{
triangle = new TriangleInfo(top, mid, bottom, triangleType, Rigidbody3d, timeStamp);
}
else
{
triangle = new TriangleInfo(mid, top, bottom, triangleType, Rigidbody3d, timeStamp);
}
TriangleBufferIndices.Add(triangleIndex);
SubmergedTriangles.Add(triangle);
return(triangle.area);
}
else if (mid.height - bottom.height < epsilon)
{
TriangleInfo triangle;
if ((top.clockwiseOrder + 1) % 3 == mid.clockwiseOrder)
{
triangle = new TriangleInfo(top, mid, bottom, 0, Rigidbody3d, timeStamp);
}
else
{
triangle = new TriangleInfo(top, bottom, mid, 0, Rigidbody3d, timeStamp);
}
TriangleBufferIndices.Add(triangleIndex);
SubmergedTriangles.Add(triangle);
return(triangle.area);
}
float tPointCutTB = (mid.height - bottom.height) / (top.height - bottom.height);
Vector3 pointCutTB = bottom.globalVertex + (top.globalVertex - bottom.globalVertex) * tPointCutTB;
VertexInfo cutTB = new VertexInfo
{
clockwiseOrder = -1, // no more use
globalVertex = pointCutTB,
height = WaterPatch.instance.DistanceToWater(pointCutTB, timeStamp),
};
TriangleInfo upside, downside;
if ((top.clockwiseOrder + 1) % 3 == mid.clockwiseOrder)
{
// downLeft: bottom, downRight: mid
upside = new TriangleInfo(top, mid, cutTB, 0, Rigidbody3d, timeStamp);
downside = new TriangleInfo(cutTB, mid, bottom, 1, Rigidbody3d, timeStamp);
}
else
{
// downLeft: mid, downRight: bottom
upside = new TriangleInfo(top, cutTB, mid, 0, Rigidbody3d, timeStamp);
downside = new TriangleInfo(mid, cutTB, bottom, 1, Rigidbody3d, timeStamp);
}
TriangleBufferIndices.Add(triangleIndex);
TriangleBufferIndices.Add(triangleIndex);
SubmergedTriangles.Add(upside);
SubmergedTriangles.Add(downside);
return(upside.area + downside.area);
}
public static Vector3 ViscousWaterResistance(float densityOfWater, float viscosityCoefficient, TriangleInfo triangle)
{
Vector3 velocity = triangle.velocity;
Vector3 normal = triangle.normal;
Vector3 tangentialVelocity = velocity - Vector3.Dot(velocity, normal) * normal;
tangentialVelocity *= -1;
tangentialVelocity.Normalize();
return(0.5f * densityOfWater * viscosityCoefficient * triangle.area * velocity.magnitude * velocity.magnitude * tangentialVelocity);
}
public static Vector3 SlammingForce(TriangleBuffer previousBuffer, TriangleBuffer currentBuffer, TriangleInfo triangle, float maxAcceleration, float rampUpPower, float totalMass, float totalArea)
{
if (triangle.cosine < 0f)
{
return(Vector3.zero);
}
Vector3 currentDeltaVolume = currentBuffer.submergedArea * currentBuffer.velocity;
Vector3 previousDeltaVolume = previousBuffer.submergedArea * previousBuffer.velocity;
Vector3 acceleration = (currentDeltaVolume - previousDeltaVolume) / (currentBuffer.originalArea * Time.fixedDeltaTime);
Vector3 stoppingForce = totalMass * triangle.velocity * (2f * triangle.area / totalArea);
float realAcceleration = Mathf.Clamp01(acceleration.magnitude / maxAcceleration);
return(-1 * Mathf.Pow(realAcceleration, rampUpPower) * triangle.cosine * stoppingForce);
}
private void CalculateForce()
{
float zMin = float.MaxValue;
float zMax = float.MinValue;
for (int i = 0; i < triangleBuilder.SubmergedTriangles.Count; ++i)
{
TriangleInfo triangle = triangleBuilder.SubmergedTriangles[i];
if (triangle.center.z < zMin)
{
zMin = triangle.center.z;
}
if (triangle.center.z > zMax)
{
zMax = triangle.center.z;
}
}
float logRigidbodyVelocity = Mathf.Log10(Rigidbody3d.velocity.magnitude);
float travelLengthScaleFactor = Mathf.Log10(zMax - zMin) * 2;
for (int i = 0; i < triangleBuilder.SubmergedTriangles.Count; ++i)
{
TriangleInfo triangle = triangleBuilder.SubmergedTriangles[i];
if (triangle.height > 0f)
{
continue;
}
float lookUpKey = (triangle.center.z - zMin) / (zMax - zMin);
float logFluidTravelLength = curveLookUpTable.LookUp(lookUpKey) * travelLengthScaleFactor;
float viscosityCoefficient = WaterInteractionUtils.CalculateViscosityCoefficient(logRigidbodyVelocity, logFluidTravelLength, logViscosity);
int TriangleBufferIndex = triangleBuilder.TriangleBufferIndices[i];
Vector3 buoyancyForce = WaterInteractionUtils.BuoyancyForce(densityOfWater, triangle);
Vector3 viscousWaterResistance = WaterInteractionUtils.ViscousWaterResistance(densityOfWater, viscosityCoefficient, triangle);
Vector3 pressureDragForce = WaterInteractionUtils.PressureDragForce(triangle, referenceSpeed, pdCoefficient1, pdCoefficient2, pdFallOffPower, sdCoefficient1, sdCoefficient2, sdFallOffPower);
Vector3 slammingForce = WaterInteractionUtils.SlammingForce(triangleBuilder.PreviousBuffers[TriangleBufferIndex], triangleBuilder.CurrentBuffers[TriangleBufferIndex], triangle, maxAcceleration, smRampUpPower, Rigidbody3d.mass, TotalArea);
Vector3 netForce = Vector3.zero;
if (debugBuoyancyForce)
{
netForce += buoyancyForce;
}
if (debugViscousWaterResistance)
{
netForce += viscousWaterResistance;
}
if (debugPressureDrag)
{
netForce += pressureDragForce;
}
if (debugSlammingForce)
{
netForce += slammingForce;
}
Rigidbody3d.AddForceAtPosition(netForce, triangle.center);
// Debug.DrawRay(triangle.center, slammingForce, Color.white);
// Debug.DrawRay(triangle.center, triangle.normal, Color.white);
// Debug.DrawRay(triangle.center, buoyancyForce, Color.blue);
// Debug.DrawRay(triangle.center, viscousWaterResistance, Color.green);
}
}
