public static Vector3 GetTriangleCenter(VertexInfo vi1, VertexInfo vi2, VertexInfo vi3, int triangleType)
{
Vector3 v1 = vi1.globalVertex;
Vector3 v2 = vi2.globalVertex;
Vector3 v3 = vi3.globalVertex;
if (triangleType == 0)
{
// vi1 is upside vertex and vi2, vi3 are horizontal downside vertices
float z0 = vi1.height;
float h = vi2.height - vi1.height;
float tCenter = (4 * z0 + 3 * h) / (6 * z0 + 4 * h);
Vector3 v1ToMid = (v2 + v3) / 2f - v1;
return(v1 + v1ToMid * tCenter);
}
else if (triangleType == 1)
{
// vi1, vi2 are horizontal upside vertices and vi3 is downside vertex
float z0 = vi1.height;
float h = vi3.height - vi1.height;
float tCenter = (2 * z0 + h) / (6 * z0 + 2 * h);
Vector3 v3ToMid = (v1 + v2) / 2f - v3;
return(v3 + v3ToMid * tCenter);
}
else
{
return((v1 + v2 + v3) / 3f);
}
}
private float CuttingAlgorithmOneAbove(VertexInfo top, VertexInfo mid, VertexInfo bottom, int triangleIndex)
{
float submergedArea = 0f;
float tPointCutTB = -bottom.height / (top.height - bottom.height);
Vector3 pointCutTB = bottom.globalVertex + (top.globalVertex - bottom.globalVertex) * tPointCutTB;
VertexInfo cutTB = new VertexInfo
{
clockwiseOrder = -1,
globalVertex = pointCutTB,
height = WaterPatch.instance.DistanceToWater(pointCutTB, timeStamp),
};
float tPointCutTM = -mid.height / (top.height - mid.height);
Vector3 pointCutTM = mid.globalVertex + (top.globalVertex - mid.globalVertex) * tPointCutTM;
VertexInfo cutTM = new VertexInfo
{
clockwiseOrder = -1,
globalVertex = pointCutTM,
height = WaterPatch.instance.DistanceToWater(pointCutTM, timeStamp),
};
if ((top.clockwiseOrder + 1) % 3 == mid.clockwiseOrder)
{
// downLeft: bottom, downRight: mid
cutTB.clockwiseOrder = (mid.clockwiseOrder + 1) % 3;
cutTM.clockwiseOrder = (cutTB.clockwiseOrder + 1) % 3;
}
else
{
// downLeft: mid, downRight: bottom
cutTM.clockwiseOrder = (mid.clockwiseOrder + 1) % 3;
cutTB.clockwiseOrder = (cutTM.clockwiseOrder + 1) % 3;
}
VertexInfo[] sortingVertices = new VertexInfo[] { mid, cutTB, cutTM };
Array.Sort(sortingVertices);
submergedArea += CuttingAlgorithmHorizontal(sortingVertices[0], sortingVertices[1], sortingVertices[2], triangleIndex);
if ((top.clockwiseOrder + 1) % 3 == mid.clockwiseOrder)
{
// downLeft: bottom, downRight: mid
bottom.clockwiseOrder = (mid.clockwiseOrder + 1) % 3;
cutTB.clockwiseOrder = (bottom.clockwiseOrder + 1) % 3;
}
else
{
// downLeft: mid, downRight: bottom
cutTB.clockwiseOrder = (mid.clockwiseOrder + 1) % 3;
bottom.clockwiseOrder = (cutTB.clockwiseOrder + 1) % 3;
}
sortingVertices = new VertexInfo[] { mid, cutTB, bottom };
Array.Sort(sortingVertices);
submergedArea += CuttingAlgorithmHorizontal(sortingVertices[0], sortingVertices[1], sortingVertices[2], triangleIndex);
return(submergedArea);
}
private float CuttingAlgorithmTwoAbove(VertexInfo top, VertexInfo mid, VertexInfo bottom, int triangleIndex)
{
float tPointCutTB = -bottom.height / (top.height - bottom.height);
Vector3 pointCutTB = bottom.globalVertex + (top.globalVertex - bottom.globalVertex) * tPointCutTB;
VertexInfo cutTB = new VertexInfo
{
clockwiseOrder = -1,
globalVertex = pointCutTB,
height = WaterPatch.instance.DistanceToWater(pointCutTB, timeStamp),
};
float tPointCutMB = -bottom.height / (mid.height - bottom.height);
Vector3 PointCutMB = bottom.globalVertex + (mid.globalVertex - bottom.globalVertex) * tPointCutMB;
VertexInfo cutMB = new VertexInfo
{
clockwiseOrder = -1,
globalVertex = PointCutMB,
height = WaterPatch.instance.DistanceToWater(PointCutMB, timeStamp),
};
if ((top.clockwiseOrder + 1) % 3 == mid.clockwiseOrder)
{
// downLeft: bottom, downRight: mid
cutTB.clockwiseOrder = (bottom.clockwiseOrder + 1) % 3;
cutMB.clockwiseOrder = (cutTB.clockwiseOrder + 1) % 3;
}
else
{
// downLeft: mid, downRight: bottom
cutMB.clockwiseOrder = (bottom.clockwiseOrder + 1) % 3;
cutTB.clockwiseOrder = (cutMB.clockwiseOrder + 1) % 3;
}
if (cutTB.height > cutMB.height)
{
return(CuttingAlgorithmHorizontal(cutTB, cutMB, bottom, triangleIndex));
}
else
{
return(CuttingAlgorithmHorizontal(cutMB, cutTB, bottom, triangleIndex));
}
}
public TriangleInfo(VertexInfo vi1, VertexInfo vi2, VertexInfo vi3, int triangleType, Rigidbody rB, float timeStamp)
{
Vector3 v1 = vi1.globalVertex;
Vector3 v2 = vi2.globalVertex;
Vector3 v3 = vi3.globalVertex;
this.center = WaterInteractionUtils.GetTriangleCenter(vi1, vi2, vi3, triangleType);
// beause of simplification. center distance can be positive in submerged triangle
// if height is positive, don't add to force
this.height = WaterPatch.instance.DistanceToWater(this.center, timeStamp);
this.normal = Vector3.Cross(v2 - v1, v3 - v1).normalized;
this.velocity = WaterInteractionUtils.GetTriangleVelocity(this.center, rB);
if (this.velocity.magnitude < 0.0001f)
{
this.cosine = 0;
}
else
{
this.cosine = Vector3.Dot(this.velocity, this.normal) / this.velocity.magnitude;
}
this.area = WaterInteractionUtils.GetTriangleArea(v1, v2, v3);
}
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);
}