Function evaluate_surface 

pub fn evaluate_surface<P: Blend>(
    ku: &KnotVector,
    kv: &KnotVector,
    grid: &ControlGrid<P>,
    u: f64,
    v: f64,
    tol: Tolerances,
) -> OgeomResult<P>

Evaluate a tensor-product B-spline surface at (u, v).

Sums the (p+1) x (q+1) non-zero basis products over the control window. Only that window contributes (the basis has local support), so cost depends on the degrees, not on the size of the surface.

Errors

OgeomError::Dimension on a shape mismatch, and OgeomError::Domain if a parameter is outside its knot vector’s domain.