Accuracy Issues With GetParamAtPoint in Surface Evaluator

[Anonymous]

Hi all,

I am having accuracy issues when dealing with Surface Evaluator's GetParamAtPoint method. As a test, I generated parameter values across a surface, Iocated their global coordinates, and then used GetParamAtPoint with default inital guesses to recalculate the parameter values.

For the attached surface, I considered an extruded spline. The extrusion surface has massive variations in accuracy in the periodic direction, and was only accurate for a small range close to one of the sides, with the majority of the errors in the order of 50% of the paramter range. The return SolutionNature always returns ints instead of enums as 0 (assumingly Could not determine solution) strategy. The accuracy does not significantly improve when initialising the guessParams in the middle of the range.

Any ideas on how to improve the accuracy of this function? Or, does anybody know the method it uses to calculate it?

Kind Regards,

Aaron