Orientate symbols based on angles between points?

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10-02-2014 04:31 AM
KeaganAllan
New Contributor III

Hi,

I have a question that I have been struggling with for a while.

I have a project where I need to place the same polygon (house footprint) at various locations within a property boundary.

The footprints are always the same, and are orientated differently.

I have the coordinates of the longest section of wall, and these have been captured the same way each time (i.e. The first point is always the entrance to the house).

I could manually draw in the house footprint each time, however I have a large number (thousands) to do.

I would like to programmatically (automatically) create these footprints, from the coordinates.

I have thought of two ways, but am struggling to find a decent starting point for each.

1) I create a polygon symbol (marker) and overlay that onto the map, orientated by the angle between the two points.

2) Create a polygon / polyline where each vertex is created in relation to the last and is based on the dimensions of the footprint.

(i.e.) From point 1, create the arc at 40 degrees for 6m, then create the next 90 degrees to that 4m away, then create the next 270 degrees from that...and so on to get the footprint drawn.

Is any of this possible?

If not, I will have to look at a CAD solution, which I would prefer not to.

Thanks,

K

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6 Replies
AnthonyGiles
Frequent Contributor

Keagan,

If you have an advanced license you can use the near table tool to work out the angles between your points that you can then use to rotate your symbol as per option one.

Because the tool calculates the distance, angle between every point to every other point, you will need a common field for your two points used to denote the front of one of your footprints to use after the near analysis has run. You can select those points where the common field is the same value.

hope that makes sense

regards

anthony

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KeaganAllan
New Contributor III

Hi Anthony,

I had considered this method. However since posting the query, I have been informed the PM wants to show the polylines / polygons in different colours - based on set criteria.

Which means "Near" method isnt really going to cut it.

Is there a way to predefine coordinates from a starting location?

Each polyline / polygon feature will look identical, just the orientation changes.

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AnthonyGiles
Frequent Contributor

Keagan,

i am a bit lost with what you have as your starting point, a couple of tools that may help are:

bearing distance to line management:

ArcGIS Help 10.1

or points to line:

ArcGIS Help 10.1

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KeaganAllan
New Contributor III

Hi Anthony,

I guess the best way to describe it would be:

1) I have 2 points, a starting point (a corner of a structure) and a corner point. These points provide a direction and length of the longest "Wall" of the structure.

2) Each structure is identical, only difference is the orientation. I was thinking of using a marker symbol (as you suggested) with the Near tool to symbolise the structure.

3) Problem has arisen that the PM wants to have the structure symbolised a certain way, depending on a criteria unique to each structure. So the marker symbol may not work.

4) I am looking for a functionality (akin to the old Logo programming language) where i can choose a starting point and "draw" the structure automatically.

Is this possible?

I am using vb.net.

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AnthonyGiles
Frequent Contributor

Is there a reason why you cannot use unique values to symbolise your markers in different colours:

ArcGIS Help 10.1

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KeaganAllan
New Contributor III

Ah, I think there is a mix-up in my explanation.

My plan was to generate a picture marker symbol, use that to symbolise the structures.

I have a few other issues with this method, but I havent ruled it out yet.

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