public Parametrisation FindNearest(
IParametricSurface surface,
Point3D referencePoint
)
{
Parametrisation closestParametrisation = new Parametrisation();
var closestDistance = double.MaxValue;
for (var u = 0; u < SamplesU; ++u)
{
for (var v = 0; v < SamplesV; ++v)
{
var paramU = u / (SamplesU - 1.0);
var paramV = v / (SamplesV - 1.0);
var location = surface.Evaluate(paramU, paramV);
var distance = (referencePoint - location).Length;
if (closestDistance > distance)
{
closestDistance = distance;
closestParametrisation = new Parametrisation(
paramU,
paramV
);
}
}
}
return(closestParametrisation);
}
public static Point3D Evaluate(
this IParametricSurface surface,
Parametrisation parametrisation
)
{
return(surface.Evaluate(
parametrisation.U,
parametrisation.V
));
}
public void DrawDerivative(
IParametricSurface surface,
double u,
double v,
DerivativeParameter parameter,
Color?color = null
)
{
var point = surface.Evaluate(u, v);
var derivative = surface.Derivative(u, v, parameter);
DrawVector(point, derivative, derivative.Length, color);
}
/// <summary>
/// Calculates F(u,v) = dot(P(u,v) - P, t) - d
/// </summary>
/// <param name="surface"></param>
/// <param name="parametrisation"></param>
/// <param name="previousPoint"></param>
/// <param name="tangentVector"></param>
/// <returns></returns>
private DenseVector EvaluatePlaneEquation(
IParametricSurface surface,
Parametrisation parametrisation,
Vector previousPoint,
Vector tangentVector
)
{
var surfacePosition =
((Vector3D)surface.Evaluate(parametrisation)).ToMathVector();
var position = surfacePosition - previousPoint;
var dot = position.DotProduct(tangentVector);
var tangentZeroEquationValue = dot - TrackingDistance;
var tantentPlaneEquationVector = DenseVector.OfArray(new[]
{
tangentZeroEquationValue,
tangentZeroEquationValue,
tangentZeroEquationValue
});
return(tantentPlaneEquationVector);
}
protected void ScanConstantParameter(
Func <int, double> uCoordGenerator,
Func <int, double> vCoordGenerator,
int samples)
{
for (var i = 0; i < samples; ++i)
{
var u = uCoordGenerator(i);
var v = vCoordGenerator(i);
if (_sampledSurface.Trimmer != null &&
!_sampledSurface.Trimmer.VerifyParametrisation(u, v))
{
_builder.FinishChain();
}
else
{
_builder.Connect(_sampledSurface.Evaluate(u, v));
}
}
_builder.FinishChain();
}