A curve parameter is a numeric value that defines a location along the curve, ranging from the start of the curve being crv.domainMin to the end of the curve being crv.domainMax.
You can generate a cartesian x,y,z point value at a curve parameter by using crv.evaluatePoint( t ), or other information at that position with crv.evaluateTangent( t ), crv.evaluateCurvature( t ) or crv.evaluateDerivatives( t ).
