TL Catenary 3D
Win32 and 64, EnglishGeneral Usage Instructions
Click on any of the app icons installed in the Addins tab (or run the commands directly by typing them in the command area in AutoCAD) and follow the onscreen prompts to select the input parameters and generate a catenary polyline. Old values of the various input parameters are retained and can be reused by accepting the defaults at the command prompt.
All input/output is relative to the current/active UCS and all units are in the current dwg linear units setting.
Please follow each command description for usage.
For the complete documentation refer to the offline Help file from the below location.
C:\ProgramData\Autodesk\ApplicationPlugins\Todor Latev TL Catenary 3D.bundle\Contents\Help.html
Commands
Ribbon/Toolbar Icon  Command  Command Description 


TLCatenaryA 
Generates a catenary curve using a base point and a parameter "a" specified by the user 

TLCatenaryA3d 
Launches the TLCatenaryA command in 3D mode. This mode changes the coordinate system internally so that the vector of gravity is aligned with the Z axis of the current/active UCS and the Catenary XY plane is aligned with the two control points. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system 

TLCatenaryLength 
Generates a catenary curve using a start and end points and a total length specified by the user 

TLCatenaryLength3d 
Launches the TLCatenaryLength command in 3D mode. This mode changes the coordinate system internally so that the vector of gravity is aligned with the Z axis of the current/active UCS and the Catenary XY plane is aligned with the two control points. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system 

TLCatenarySlope 
Generates a catenary curve using a start and end points and a slope at a location all specified by the user 

TLCatenarySlope3d 
Launches the TLCatenarySlope command in 3D mode. This mode changes the coordinate system internally so that the vector of gravity is aligned with the Z axis of the current/active UCS and the Catenary XY plane is aligned with the two control points. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system 

TLCatenarySag 
Generates a catenary curve using a start and end points and a sag specified by the user 

TLCatenarySag3d 
Launches the TLCatenarySag command in 3D mode. This mode changes the coordinate system internally so that the vector of gravity is aligned with the Z axis of the current/active UCS and the Catenary XY plane is aligned with the two control points. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system 

TLCatenaryBulge 
Generates a catenary curve using a start and end points and a bulge specified by the user 

TLCatenaryBulge3d 
Launches the TLCatenaryBulge command in 3D mode. This mode changes the coordinate system internally so that the vector of gravity is aligned with the Z axis of the current/active UCS and the Catenary XY plane is aligned with the two control points. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system 

TLCatenaryVerticalBulge 
Generates a catenary curve using a start and end points and a vertical bulge specified by the user 

TLCatenaryVerticalBulge3d 
Launches the TLCatenaryVerticalBulge command in 3D mode. This mode changes the coordinate system internally so that the vector of gravity is aligned with the Z axis of the current/active UCS and the Catenary XY plane is aligned with the two control points. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system 

TLCatenaryArea 
Generates a catenary curve using a start and end points and enclosed area specified by the user 

TLCatenaryArea3d 
Launches the TLCatenaryArea command in 3D mode. This mode changes the coordinate system internally so that the vector of gravity is aligned with the Z axis of the current/active UCS and the Catenary XY plane is aligned with the two control points. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system 

TLCatenaryPoints 
Generates a catenary curve trough three known points specified by the user 

TLCatenaryPoints3d 
Launches the TLCatenaryPoints command in 3D mode. This mode changes the coordinate system internally so that the resulting catenary lies in the 3d plane defined by the control points and the vector of gravity is aligned with the Z axis of the current/active UCS as close as possible. All coordinates are still transformed back to the current UCS, but the Catenary equation parameters are reported in the internal coordinate system. The catenary curve will pass through all 3 points but the direction of gravity may deviate from the Z direction depending on the configuration of the input points. The resulting curve is still sensitive to the orientation of the UCS and different UCS systems will result in different curves for the same set of control points 

TLCatenaryBestFit 
Generates a catenary curve by performing a least squares error function optimization on a set of input points. The Error function is defined as the sum of squares of the catenary residuals at every point in the set. In addition to the standard output a residuals list is generated for all input points along with the final value of the error function. 

TLCatenaryBestFit3d 
Launches the TLCatenaryBestFit command in 3D mode. In this mode the least squares optimization is computed in multiple stages. During the first stage a best fit 3d plane is derived off of the set of control points. This plane is then used to compute a catenary local coordinate system taking the UCS gravity vector into account. Finally a best fit least squares analysis is computed during the third stage. Note that the function minimization during the first stage is performed orthogonally to the plane whereas in the third stage the vertical distance (along the Y or Z vector) is minimized. As is the case with the CatenaryPoints3d command the resulting curve is still sensitive to the orientation of the UCS and different UCS systems will result in different curves for the same set of control points. 

TLCatenary3dActivate 
Activates the TL Catenary 3d App with the Autodesk App Store. Active internet connection is required. Once activated the app can be used offline. This command is not available in the ribbon and needs to be manually typed in at the AutoCAD command prompt 
Installation/Uninstallation
The installer that ran when you downloaded this app/plugin from Autodesk App Store will start installing the app/plugin. OR, simply doubleclick the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plugin. To uninstall this plugin, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system.
Once the installation is complete, start AutoCAD and log in with your Autodesk user id and password. Run the TLCatenaryActivate command to activate the app. Once activated the app can be used offline.
Additional Information
Known Issues
In certain special cases the catenary curve is undefined: for example when all three points lie on the same line or where vertical points exist etc. Additionally, certain input parameters may cause the catenary to shoot off to positive/negative infinity quite rapidly. In those extreme cases due to reasons such as limitations of the computer floatingpoint numbers range, numerical instability, roundoff errors etc the program might not be able to compute all catenary points. No polyline or incomplete polyline may be generated.
Contact
Author/Company Information
Support Information
For questions/comments/suggestions/bug reports etc please email to: Todor.Latev@gmail.com
Version History
Version Number  Version Description 

2023.6.3.1 
TLCatenaryBestFit & TLCatenaryBestFit3d commands updated to allow selection of multiple Autocad point objects 
2019.9.10.1 
Added 2024 support. 