Automatically Generate Survey Surfaces
Civil 3D from Autodesk is a fantastic program that I use on a daily basis, so you’ll see a lot of reference to it on this site. Since I’m responsible for implementation and training of this software as the primary design package in fifteen regional offices and 400+ employees, you’d think I’d know everything there is to know about it, right? Nope. One of the things I love about the CAD world is that there’s always something new to learn and if you don’t acknowledge that, then you’re a fool.
A few months back, I was doing some customization for my survey group when one of my better survey drafters pointed out a process they’d come up with for “automatically” building existing surfaces when they import their original survey point data from the field. I freely admit, I didn’t believe her at first but I’ve learned enough about my own stupidity over the years to never scoff at other people’s ideas until I’ve heard them out. She took me through what she wanted to do and my jaw hit the floor: it was completely automated and it worked like a charm. It’s now part of my standard survey prototype drawing and I’m going to show you how quick and simple it is to set it up for your own firm.
Step One: Description Keys
Anyone working in the survey field is familiar with Civil 3D Description Keys. They’re simple text strings that read your input data from the data collectors and tell Civil 3D how to display it on screen. For example, a point coded as TRD-12 by the field crew comes in with a deciduous tree symbol and is annotated as “Tree, Deciduous – 12 in.” Most firms already have a description key file set up and ready to go.
If you’re not working with one, you’re missing out on a truly powerful tool and you should look into it immediately. If you already have one set up, then you’re ready to move on.
Step Two: Point Groups
Point groups are another staple of the survey CAD world. They allow you to group similar points into a named group for quick access and reference. As an example, you could take all the points that have a description of: TC and assemble them into a group called “Top of Curb” for easily editing all your top of curb points at once. What we want to do for this process is create a point group called “Topo” that includes all the descriptors that you use for real world objects that would be included in your existing surface, such as top and bottom of curb, ground shots, road centerlines, top and bottom of walls, banks, etc.
In Civil 3D you can create this group using the raw descriptor keys and save it as part of your default survey template file (.DWT) even though there are no defined points in your file.
Ok, so we have our point group built from our description keys so that when we import our field data the points are automatically labeled, symbols inserted, put on the correct layers and assembled into our “Topo” group. How is that going to automatically generate a surface for us? By creating a pre-named surface that is defined from a single point group, that’s how. In your toolspace, create a new surface called “Surveyed Existing” and expand the definition tree so you can see the “Point Groups” option.
Right click on it and select ADD, then select the “Topo” point group and hit OK. Now save your template file and you’re done.
So you followed the steps above and now you’re wondering how this all actually works, right? Too easy! Start a new drawing from our “Survey Template.DWT” file and all the components we made above are already in place. Now, all you need to do is import your point file into the new drawing and your surface will be automatically created. How? Well, on import, the description keys place all points onto the right layers, etc.
so they appear correctly on your screen. At the same time, the Point Group filters are moving everything you chose into our “Topo” point group and the “Surveyed Existing” surface is instantly built from any points that are put into that group.
Because Civil 3D is a drawing based design package where all data is created inside the DWG file, instead of an external database as it was in the older Land Desktop Companion software you can put predefined setups like this into play. Also, the design elements in Civil 3D are all dynamic, meaning they automatically update as their component parts are updated, the entire process becomes automatic. In other words, when we add points to the drawing, the point group is updated and as soon as the point group is updated, the surface using that group as a component is also updated, instantly creating a surface for you. You can even set the display style, etc. you want for the surface so it displays correctly from the start.
To be fair, this surface isn’t fully complete.
You’ll still want to add breaklines, boundaries, etc. to fine tune it but this tip gets you about 90% complete without your drafters ever having to lift a finger. Now, that is automation that we can all get behind!
Civil 3D from Autodesk is a fantastic program that I use on a daily basis, so you’ll see a lot of reference to it on this site. Since I’m responsible for implementation and training of this software as the primary design package in fifteen regional offices and 400+ employees, you’d think I’d know everything there is to know about it, right? Nope. One of the things I love about the CAD world is that there’s always something new to learn and if you don’t acknowledge that, then you’re a fool.
A few months back, I was doing some customization for my survey group when one of my better survey drafters pointed out a process they’d come up with for “automatically” building existing surfaces when they import their original survey point data from the field. I freely admit, I didn’t believe her at first but I’ve learned enough about my own stupidity over the years to never scoff at other people’s ideas until I’ve heard them out. She took me through what she wanted to do and my jaw hit the floor: it was completely automated and it worked like a charm. It’s now part of my standard survey prototype drawing and I’m going to show you how quick and simple it is to set it up for your own firm.
Step One: Description Keys
Anyone working in the survey field is familiar with Civil 3D Description Keys. They’re simple text strings that read your input data from the data collectors and tell Civil 3D how to display it on screen. For example, a point coded as TRD-12 by the field crew comes in with a deciduous tree symbol and is annotated as “Tree, Deciduous – 12 in.” Most firms already have a description key file set up and ready to go.
If you’re not working with one, you’re missing out on a truly powerful tool and you should look into it immediately. If you already have one set up, then you’re ready to move on.
Step Two: Point Groups
Point groups are another staple of the survey CAD world. They allow you to group similar points into a named group for quick access and reference. As an example, you could take all the points that have a description of: TC and assemble them into a group called “Top of Curb” for easily editing all your top of curb points at once. What we want to do for this process is create a point group called “Topo” that includes all the descriptors that you use for real world objects that would be included in your existing surface, such as top and bottom of curb, ground shots, road centerlines, top and bottom of walls, banks, etc.
In Civil 3D you can create this group using the raw descriptor keys and save it as part of your default survey template file (.DWT) even though there are no defined points in your file.
Ok, so we have our point group built from our description keys so that when we import our field data the points are automatically labeled, symbols inserted, put on the correct layers and assembled into our “Topo” group. How is that going to automatically generate a surface for us? By creating a pre-named surface that is defined from a single point group, that’s how. In your toolspace, create a new surface called “Surveyed Existing” and expand the definition tree so you can see the “Point Groups” option.
Right click on it and select ADD, then select the “Topo” point group and hit OK. Now save your template file and you’re done.
So you followed the steps above and now you’re wondering how this all actually works, right? Too easy! Start a new drawing from our “Survey Template.DWT” file and all the components we made above are already in place. Now, all you need to do is import your point file into the new drawing and your surface will be automatically created. How? Well, on import, the description keys place all points onto the right layers, etc.
so they appear correctly on your screen. At the same time, the Point Group filters are moving everything you chose into our “Topo” point group and the “Surveyed Existing” surface is instantly built from any points that are put into that group.
Because Civil 3D is a drawing based design package where all data is created inside the DWG file, instead of an external database as it was in the older Land Desktop Companion software you can put predefined setups like this into play. Also, the design elements in Civil 3D are all dynamic, meaning they automatically update as their component parts are updated, the entire process becomes automatic. In other words, when we add points to the drawing, the point group is updated and as soon as the point group is updated, the surface using that group as a component is also updated, instantly creating a surface for you. You can even set the display style, etc. you want for the surface so it displays correctly from the start.
To be fair, this surface isn’t fully complete.
You’ll still want to add breaklines, boundaries, etc. to fine tune it but this tip gets you about 90% complete without your drafters ever having to lift a finger. Now, that is automation that we can all get behind!
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