Question about point groups for a newbie...

[brocksmith45]

Hello all. I have be learning Civl 3D by trial and error over the past month. I am a land surveyor and had used Carlson Survcad for several years. We had a pretty old version of Autocad, but I cant remember exactly which one(probably mid to late 90s version). Long story short, I have started working at a new company that uses Civil 3D 2012, and needless to say there is a lot for me to learn.

I have gradually re-learned basic autocad functions, but still struggling a bit with some of the Point Group features.

I recently performed a large boundary and topographic survey which resulted in thousands of shots in the field. For future boundary uses, I'm creating a drawing for each state plane zone that I work in so that all boundary data will be located conveniently in one drawing without all the clutter of the topo data.

In the past using Carlson I would simply copy the linework of the property boundary, and create a new coordinate file that only has the few points that are crucial to boundary work.

So my question is what is the best way to do this in Civil 3D? To recap, I want to select about 10 cogo points from a point group of thousands of irrelevant points that will never be used again, and place them in a new drawing.

Thanks for any help you can offer. 

[rkmcswain]

---

@brocksmith45 wrote:

......I want to select about 10 cogo points from a point group of thousands of irrelevant points that will never be used again, and place them in a new drawing.

---

Maybe I'm misunderstanding, but to specifically answer the question quoted above.... you can copy the 10 points to the clipboard, and switch to the second drawing and paste them in.

[Jay_B]

This can eassily be done by setting up a point group of your 10 points you wish to extract for a reimport into another file etc.

General Information on point groups for 2012 C3D can be found Here

Then go to the Modify Tab of Ribbon_Ground Data Panel_Points_Cogog Point Tools_Export Points_Check "Limit Points to Point Group" and populate rest of fields on "Export Points" dialog_OK.

You should now have an ascii exported of your 10 points.

[brocksmith45]

I thought about this but wondered if the point groups would be added to the drawing as well. The points span about 10 groups, with each group representing a different day of field work. The points I want to trim out are one or two points from each group. So would all those original point groups show up in the new drawing? Sorry if my wording is confusing.

And this is kind of a related question... If I have 10 different point groups, each being a days worth of field data imported from a txt file, what is the best way to combine all of them into one point group so they are easier to handle?

[brocksmith45]

And thanks Jay. I believe this will help

[Jay_B]

It takes a bit of time but I think you're possibly misunderstanding Point Groups.

Your daily surveys are considered an "Import Event" to Civil 3D and as you import these various survey files they too will appear in your Point Groups Listing. The _All Points Point Group has all the points included from all surveys.

I like to think of Point Groups as a means for "display" or "filtering" of points.

Some great uses for Point Groups would be:

1. "EG Surface Points" - This allows you to filter out the unwanted Survey Points not wanted in tin creation such as fire hydrants etc.

2. Topo Points - A Point Group can be created just to show the topo points.

3. Survey Points - Property Irons, Monuments etc.

4. Utilities - View only utility related points.

These are just a few examples of ways we use them.

I'd recommend reading up on Point Groups as they are very handy once you get the concept down.

Hope this helps.

[brocksmith45]

Thanks for all the tips.

[troma]

Remember that point groups are not mutually exclusive; a given cogo point can be included in one, two, three or five hundred groups, if so desired.  So you can carry on keeping point groups of each day's work if you find that useful, but also use other groups for the purposes Jay mentioned.