TL Clothoid
Win64, EnglishGeneral Usage Instructions
Utilize the curve creation commands to compute and draw standalone Clothoid spirals in AutoCAD. Once a Clothoid is computed an additional set of commands is available to query/manipulate the curve. All Clothoid parameters are retained in memory and can be reused for subsequent invocation of any Clothoid commands.
Use the Points setting to control the number of vertices of the generated polyline as well as how the distance between those points is computed:
* positive number of +n means a point will be computed every n units along the curve
* negative number n will be rounded to the nearest integer and will be interpreted by the app as the total number of points along the entire curve. The distance between individual points will be autocomputed. Note that total points cannot be more than 1000.
Use the Error setting to control the max allowed error in the point position. This number should be more than zero and less than or equal to one. Note that adjusting this number does not effect the internal computation. It only establishes an acceptable threshold which if exceeded causes the point to be rejected and not used in the Clothoid polyline
You can use the UCS command in AutoCAD to align the coordinate system to your alignment segment. The Clothoid app respects the active UCS and the polylines generated will have the proper orientation
Refer to the individual command descriptions for more information on each available command
Commands
Ribbon/Toolbar Icon  Command  Command Description 


TLClothoidLengthParameterA 
Computes a Clothoid defined by a <Length> and <Parameter A> parameters, draws the curve as a polyline in Autocad. The number of polyline vertices is controlled by the Points setting. The accuracy of each computed point is controlled by the MaxError setting 

TLClothoidLengthRadius 
Computes a Clothoid defined by a <Length> and <Radius> parameters, draws the curve as a polyline in Autocad. The number of polyline vertices is controlled by the Points setting. The accuracy of each computed point is controlled by the MaxError setting 

TLClothoidLengthTangent 
Computes a Clothoid defined by a <Length> and <Tangent> (0<tangent<=Pi) parameters, draws the curve as a polyline in Autocad. The number of polyline vertices is controlled by the Points setting. The accuracy of each computed point is controlled by the MaxError setting 

TLClothoidRadiusParameterA 
Computes a Clothoid defined by a <Radius> and <Parameter A> parameters, draws the curve as a polyline in Autocad. The number of polyline vertices is controlled by the Points setting. The accuracy of each computed point is controlled by the MaxError setting 

TLClothoidRadiusTangent 
Computes a Clothoid defined by a <Radius> and <Tangent> (0<tangent<=Pi) parameters, draws the curve as a polyline in Autocad. The number of polyline vertices is controlled by the Points setting. The accuracy of each computed point is controlled by the MaxError setting 

TLClothoidTangentParameterA 
Computes a Clothoid defined by a <Tangent> (0<tangent<=Pi) and <Parameter A> parameters, draws the curve as a polyline in Autocad. The number of polyline vertices is controlled by the Points setting. The accuracy of each computed point is controlled by the MaxError setting 

TLClothoidRedrawLast 
Redraws the last computed Clothoid curve. Allows for changes in base point position, UCS, Points and MaxError settings 

TLClothoidDrawSegment 
Draws a polyline of the last computed Clothoid from a custom range of start/end stations. Allows for changes in base point position, UCS, Points and MaxError settings 

TLClothoidSolveSegmentalParamete 
Allows the user to pick two arcs or circles on the screen and computes a <Parameter A> value, such that a single segmental Clothoid can be drawn to smoothly transition from one radius to the other from the given geometry. Once the A value is computed issue the TLClothoidRadiusParameterA command and specify the smaller radius and the computed A value. Then follow up with the TLClothoidLocateRadius command to visualize the bigger radius. Finally use the Autocad align command and point to the two pairs of center points to position the spiral 

TLClothoidLocateStation 
Draws a point along a computed Clothoid curve at a user specified station/length. Station value can be positive or negative 

TLClothoidLocateRadius 
Visualizes the radius/station of a computed Clothoid curve having a user specified Radius value. Radius value can be positive or negative 

TLClothoidLocateTangent 
Draws a point and a line, visualizing the Clothoid tangent/station for a user specified Tangent value. Tangent value must be within 0 and Pi values. Both positive and negative cases are drawn. 

TLClothoidActivate 
Activates the TL Clothoid App with the Autodesk App Store. An 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) and uninstall as you would any other application from your system.
Additional Information
Euler spiral Wiki page:
https://en.wikipedia.org/wiki/Euler_spiral
Known Issues
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 

2022.1.20.1 
Initial release 