Wednesday, August 08, 2018

Notes on Starting Out Programming

It's mainly about having a problem to solve and then taking the steps to accomplish the task. I am usually just taking the workflow that one would be doing in AutoCAD and automating it. Google and Bing are a great source to find code snippets that can be modified to suit the needs of the code.

Getting started for an Autodesk project is covered in this AKN:

Creating a bundle file to autoload in AutoCAD:

This book helps teach how to better organize code:

The source code for the free version of the SincPac is a great resource for Civil 3D coding:

Monday, July 09, 2018

Just a Random Thought

Why spend so much time renaming modeling? Seems a better use of time would be to create great tools that users would want to use. Why would I want to use products that need to win a Dundie type award to stand out?

Sunday, July 08, 2018

Curb Return Design - Plane Method

This is in response to @jwilkerson post from years ago, found in this post:

The referenced formula is here: ArchiveLink

Not sure what the error he was referencing. It looks like the G2 arrow shown in the image is going in the wrong direction. I think it should be going from PI1 to B direction for the flow of water. It looks like they corrected the error in the PI3 by having the formula reverse the G2 slope. Here is a link to an Excel spreadsheet and a link to a drawing showing a plane solution that checks the values via a model. Both the drawing and Excel spreadsheet should be checked for correctness. It is provided only as a reminder to myself, since I’ve created this Excel spreadsheet before and forgot where I put it. Hopefully Google will find it next time I’m looking for it.


Monday, February 26, 2018

Surveying Related Ideas

Often times we need to create rectangles to represent existing features that look like rectangles.  To save time surveyors will shoot two points and then in the office convert those two points into rectangles. With lisp we can automate the rectangle creation down to picking two clicked points.

  • This forum post has some lisp code that does just that. Here is a link to a text file with the code extracted in case the forum post goes down.
  • To run the lisp save it to a text file with the extension of .lsp
  • Type Appload at the command line.
  • If you want to run it once, select the file from the upper portion of the Appload dialog box.
  • If you want the lisp to load everytime AutoCAD is run, then add the lisp file to the Startup Suite.


A second desired workflow is to create a point at the intersection of two selected objects, the objects don’t have to intersect. The objects may be arc, line, polyline, lot line, or feature line.


To start open the Point Create Creation Tools.


Then under the second drop down choose the Object/Object option.


Then follow the prompts. This will create a point where the objects intersect. If you want to remove any of the prompts you can change the settings of the Point Creation command using the double down arrow on the right of the Create Points toolbar.

Friday, February 16, 2018

Average Cut and Fill

I have no idea what the Average Cut and Average Fill of a volume surface means or how it should be calculated. It sounds like a made up term from a planner so they can come up with a made up value to judge impacts for a project. Since I don’t have a good explanation of what the average cut or fill is here is one way to do it in Civil 3D.

  1. Create the volume surface.
  2. Go into the Volume Surfaces, Analysis Tab. Change the type to Elevation, the number of Ranges to 2 and then press the down arrow to apply the 2 elevation ranges. image
    1. Change the Ranges to 0 for the Maximum Elevation for the first range and 0 for the minimum elevation for the second line. image
    2. Then create a Surface Legend table for the Elevation Analysis. image
    3. Now take the Cut Area and divide it by the volume of cut and the Fill Area and divide it by the volume of fill. Then you should have average cut/fill numbers. You can find the volume numbers in the volumes dashboard or on the Statistics tab. You can even add the volumes to the table.

    Now I have no idea if this is correct. I did end up with an average number that has the correct units. I can think of numerous other more complicated methods to calculate these values.


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