public static Cloth CreateQuad(ClothQuadDefinition def)
{
var resX = def.ResX;
var resY = def.ResY;
var pts = new ClothParticle[resX * resY];
for (var y = 0; y < resY; y++)
{
var fy = y / (float)(resY - 1);
var p0 = Vector3.Lerp(def.V00, def.V01, fy);
var p1 = Vector3.Lerp(def.V10, def.V11, fy);
for (var x = 0; x < resX; x++)
{
var fx = x / (float)(resX - 1);
var p = new ClothParticle {
Position = Vector3.Lerp(p0, p1, fx), Velocity = Vector3.Zero, Tension = Vector3.Zero, Uv = new Vector2(fx, fy)
};
pts[y * resX + x] = p;
}
}
#region Pin Particles
foreach (var pin in def.Pins)
{
pts[pin.Y * resX + pin.X].Pinned = true;
}
#endregion
#region Calculate Particle Masses from Area
var totalArea = 0f;
for (var y = 0; y < resY; y++)
{
for (var x = 0; x < resX; x++)
{
var idx = y * resX + x;
var pos = pts[idx].Position;
var normal = Vector3.One;
var area = 0f;
if (x < resX - 1 && y < resY - 1)
{
area += (normal = Vector3.Cross(pts[idx + 1].Position - pos, pts[idx + resX].Position - pos)).Length() / 2;
}
if (x < resX - 1 && y > 0)
{
area += (normal = Vector3.Cross(pts[idx + 1].Position - pos, pts[idx - resX].Position - pos)).Length() / 2;
}
if (x > 0 && y < resY - 1)
{
area += (normal = Vector3.Cross(pts[idx - 1].Position - pos, pts[idx + resX].Position - pos)).Length() / 2;
}
if (x > 0 && y > 0)
{
area += (normal = Vector3.Cross(pts[idx - 1].Position - pos, pts[idx - resX].Position - pos)).Length() / 2;
}
normal.Normalize();
pts[idx].Normal = normal;
pts[idx].Area = area;
pts[idx].InverseMass = def.Mass * area;
totalArea += area;
}
}
for (var i = 0; i < pts.Length; i++)
{
pts[i].InverseMass = 1 / (pts[i].InverseMass / totalArea);
}
#endregion
var springs = new List <ClothSpring>(resX * (resY - 1) + (resX - 1) * resY + (resX - 1) * (resY - 1) + (resX - 2) * (resY - 1) +
(resX - 1) * (resY - 2));
#region Create Springs
// + X
for (var y = 0; y < resY; y++)
{
for (var x = 0; x < resX - 1; x++)
{
var idx = y * resX + x;
springs.Add(new ClothSpring
{
P0 = idx,
P1 = idx + 1,
Stiffness = def.TensionStrength
});
}
}
// + Y
for (var y = 0; y < resY - 1; y++)
{
for (var x = 0; x < resX; x++)
{
var idx = y * resX + x;
springs.Add(new ClothSpring
{
P0 = idx,
P1 = idx + resX,
Stiffness = def.TensionStrength
});
}
}
// + X, +Y
if (def.ShearStrength > 0)
{
for (var y = 0; y < resY - 1; y++)
{
for (var x = 0; x < resX - 1; x++)
{
var idx = y * resX + x;
springs.Add(new ClothSpring
{
P0 = idx,
P1 = idx + resX + 1,
Stiffness = def.ShearStrength
});
}
}
}
if (def.StructuralStrength > 0)
{
// + 2X, +Y
for (var y = 0; y < resY - 1; y++)
{
for (var x = 0; x < resX - 2; x++)
{
var idx = y * resX + x;
springs.Add(new ClothSpring
{
P0 = idx,
P1 = idx + resX + 2,
Stiffness = def.StructuralStrength
});
}
}
// +X, +2Y
for (var y = 0; y < resY - 2; y++)
{
for (var x = 0; x < resX - 1; x++)
{
var idx = y * resX + x;
springs.Add(new ClothSpring
{
P0 = idx,
P1 = idx + resX * 2 + 1,
Stiffness = def.StructuralStrength
});
}
}
}
#endregion
#region Fill Spring Lengths
for (var i = 0; i < springs.Count; i++)
{
var s = springs[i];
var len = Vector3.Distance(pts[s.P0].Position, pts[s.P1].Position);
s.Length = len;
s.InvLength = 1 / len;
springs[i] = s;
}
#endregion
var quadStream = new int[4 * (resX - 1) * (resY - 1)];
#region Create Quad Stream
var quadOffset = 0;
for (var y = 0; y < resY - 1; y++)
{
for (var x = 0; x < resX - 1; x++)
{
var idx = y * resX + x;
quadStream[quadOffset++] = idx;
quadStream[quadOffset++] = idx + 1;
quadStream[quadOffset++] = idx + 1 + resX;
quadStream[quadOffset++] = idx + resX;
}
}
#endregion
var cloth = new Cloth(pts, springs.ToArray(), quadStream)
{
Damping = def.Damping
};
return(cloth);
}
public ClothSection(MyObjectBuilder_ClothSquaresComponentDefinition.ClothSquare sq)
{
Def = new ClothQuadDefinition(sq);
Bindings = sq.Pins.Where(x => !string.IsNullOrWhiteSpace(x.Bone)).Select(x => new Binding(x)).ToArray();
}
