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Helmert Transformation (also supporting C3D Objects)

Helmert Transformation (also supporting C3D Objects)

Civil 3D Users are asking to support a Helmert Transformation for several years. The 'ALIGN' command is quite similar, but only works on a pair of 2 points, while Helmert Transformation supports multiple pairs of points.

A good implementation of the software should also show the "delta's" between the pairs of points, to show points with the largest delta's so they can be excluded from the final calculation.

This forum post describes best the needs of surveyors: https://forums.autodesk.com/t5/civil-3d-forum/helmert-least-squares-best-fit-coordinate-transformati...

 

"Most surveying software has this in the form of a Helmert Transformation, which works out a scale and rotation based on point pairs i.e. common points on two coordinate sytems, using a least squares best fit."

 

"IMO, this functionality should be available as both part of the Survey Database translate tool, and as a separate tool in the Survey Analyze tab."

 

"I am arguing that this sort of transformation is basic (i.e. fundemental) to surveying, and should be an available transform in the Survey Database translate tool. I further argue that this sort of least-squares, best-fit tool should be available outside the survey database, as anytime you have real-world points and need to "best-fit" them to a model (or vice-versa), this sort of transform would be called for."

 

A third party add-in is providing this functionality, but seems to work only on plain AutoCAD objects and not on C3D Objects (Cogo Points, Alignments,...). https://apps.autodesk.com/CIV3D/en/Detail/Index?id=3236793333071302608&appLang=en&os=Win32_64

Lots of surveys result in Survey/CoGo Points, so it's crucial that those C3D objects are supported.

 

Since this is basic to suveying, this should be core functionality of Civil 3D supporting C3D objects as well, opposite to the above mentioned add-in.

2 Comments
matthew.badgerGLJM5
Community Visitor

Performing such a routine is definitely nothing new, nor is it something that is new to competing platforms. Carlson Survey named this routine "Deed Correlation," and it does a WONDERFUL job and costs much less than C3D. PC Survey has this functionality, and that platform can be purchased around $200. Triad Boundary Analysis, though a non-graphical UI, performs this routine and does an excellent job. Bentley's on the list as well. With C3D being a premium-priced product, please help those of us out who are C3D users and add this routine that your competitors already have and have had for several years.

 

I would personally prefer and think it logical for this routine to be housed under the Home->Draw->Best Fit POINTS.

 

This routine would help Land Surveyors and our workflow on many projects very much. Please, please, please add this to C3D! I am willing to help out with development of this routine, from an end-user's perspective...

pieter_haeck
Advocate

@TimYarris 
Any thoughts on this idea for the near future?

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