AutoCAD Map 3D General Discussion

AutoCAD Map 3D General Discussion

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Contributor
Paul
Posts: 16
Registered: ‎11-22-2009
Message 1 of 17 (562 Views)

Overlay Analysis

562 Views, 16 Replies
02-27-2013 02:48 PM

Help

 

I am trying to perform an OVERLAY ANALYSIS between a flood polygon and parcel polygon. I want to highlight the parcels that intersect with the flood polygon. I select SOURCE as Parcels and OVERLAY as the Food Polygon. When I perform the operation I get a result SDF that shows that area of the parcel that is flood affected. Am I missing something... I need the whole of the parcel selected..

 

Paul

*Expert Elite*
Alfred.NESWADBA
Posts: 9,583
Registered: ‎06-29-2007
Message 2 of 17 (559 Views)

Re: Overlay Analysis

02-27-2013 03:03 PM in reply to: Paul

Hi,

 

you should not use "Intersect" as overlay type (you see it already on the icons in the dialog that not all geometry will be in the resulting GIS-dataset).

 

2013-02-27 23-59-47.png

 

Instead you could try "Union" (hoping to have translated my German words correct to the Map3D-English), well I do understand the word "Union" in another way, but at least verify the resulting icons in the preview:

 

2013-02-28 00-03-13.png

 

 

HTH, - alfred -

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Alfred NESWADBA
Ingenieur Studio HOLLAUS ... www.hollaus.at
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Contributor
Paul
Posts: 16
Registered: ‎11-22-2009
Message 3 of 17 (548 Views)

Re: Overlay Analysis

02-27-2013 03:48 PM in reply to: Alfred.NESWADBA

Union does not provide the desires result. All the Help funstions show that using INTERSECT will provide what I am looking for. even when hovering over the GIS OVERLAY icon, the video that plays is what I am looking for.

Mentor
Robert_Fritz
Posts: 175
Registered: ‎12-08-2011
Message 4 of 17 (515 Views)

Re: Overlay Analysis

02-27-2013 11:52 PM in reply to: Paul

Hi,

 

I'm not sure whether I do understand what you want to do or what exactly the issue is -  but to me it looks like you need something like a Spatial Query. What you are doing right now is spatial geoprocessing - and the information displayed in the dialog box you provided says "non-oberlapping areas are discarded". Isn't that excatly what happened?

 

The spatial query capabilities in Map are still poor. You can select feature based on a window a polygon but you cannot query features based on a second set of features.

 

QGIS does this quite well have look here at this tutorial - scroll down a bit for "Spatial Query". The parcel affected but flooding would be selected - I assume thats waht you want to get as well?

 

http://qgis.spatialthoughts.com/2011/12/tutorial-performing-spatial-queries-in.html

 

Rob

http://raumpatrouille3d.blogspot.ch/
*Expert Elite*
Alfred.NESWADBA
Posts: 9,583
Registered: ‎06-29-2007
Message 5 of 17 (513 Views)

Re: Overlay Analysis

02-28-2013 12:18 AM in reply to: Robert_Fritz

Hi,

 

>> You can select feature based on a window a polygon

>> but you cannot query features based on a second set of features

Excuse me for interupting, but you don't need any third party software and export and import and ... to do that!

 

Look to my video, there are some parcels, one buffer object for a power supply line.

I do just one additional rule in the display-style for the parcels to get the parcels colorized in another color that are touched from this buffer object. (sorry that it is in German, but the icons and commands are the same)

 

- alfred -

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Alfred NESWADBA
Ingenieur Studio HOLLAUS ... www.hollaus.at
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Mentor
Robert_Fritz
Posts: 175
Registered: ‎12-08-2011
Message 6 of 17 (512 Views)

Re: Overlay Analysis

02-28-2013 12:31 AM in reply to: Alfred.NESWADBA

Hi Alfred,

 

it is as I wrote - you can select features based on a polygon (=buffer) not based on  a set of features. With your approach you need to select the buffer manually and as further limitation you can select only one polygon/buffer at a time. That works well for simple use cases though.

 

Rob

 

 

http://raumpatrouille3d.blogspot.ch/
*Expert Elite*
Alfred.NESWADBA
Posts: 9,583
Registered: ‎06-29-2007
Message 7 of 17 (486 Views)

Re: Overlay Analysis

02-28-2013 06:58 AM in reply to: Robert_Fritz

Hi,

 

>> not based on  a set of features

Ok, so it's how terms are used and sorry, I am wrong because I misunderstood the meaning or "features" how you used it.

In that case I would do an overlay and have the attributes of both "sets of features" in a new "set of features" and that gives me the aibility to get the touched parcels selected. (hopefully I have now used the correct words :smileywink: )

 

- alfred -

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Alfred NESWADBA
Ingenieur Studio HOLLAUS ... www.hollaus.at
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Mentor
olivier.eckmann
Posts: 188
Registered: ‎02-14-2009
Message 8 of 17 (461 Views)

Re: Overlay Analysis

03-01-2013 08:23 AM in reply to: Alfred.NESWADBA

Hi,

 

if you use MAPFEATUREMERGE command you can merge all features from 1st layer into one single feature (multi-polygon) and then used method explained by alfred.

 

I've seen your video and I've a question. I've tried to modify the geometry of buffer after creating the rule, but new overlapped parcels are not colored. It seems that the rule use (store) the coordinates of buffer when it's selected, and not the ID of feature. So overlay is not updated (dynamic) when geometry of buffer is modified. Is it right?

 

Olivier

*Expert Elite*
Alfred.NESWADBA
Posts: 9,583
Registered: ‎06-29-2007
Message 9 of 17 (458 Views)

Re: Overlay Analysis

03-01-2013 08:37 AM in reply to: olivier.eckmann

Hi,

 

>> It seems that the rule use (store) the coordinates of buffer when it's selected, and not the ID of feature

Sorry and sadly, yes you are right, it's just a snapshot from the vertex-coordinates of the polygon.

But if you need to do that more than once you have the aibility of the Map-Workflow to automate this overlaying.

 

- alfred -

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Alfred NESWADBA
Ingenieur Studio HOLLAUS ... www.hollaus.at
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Valued Mentor
engrtech
Posts: 765
Registered: ‎05-05-2008
Message 10 of 17 (242 Views)

Re: Overlay Analysis

04-29-2013 11:06 AM in reply to: Paul

Paul wrote:

Help

 

I am trying to perform an OVERLAY ANALYSIS between a flood polygon and parcel polygon. I want to highlight the parcels that intersect with the flood polygon. I select SOURCE as Parcels and OVERLAY as the Food Polygon. When I perform the operation I get a result SDF that shows that area of the parcel that is flood affected. Am I missing something... I need the whole of the parcel selected..

 

Paul


I am trying to do the same thing. I have a SDF of buildings and a SDF of the flood zones. I want to get all of the buildings that are in a flood zone. When I do the feature overlay, I did Intersect because that's what the help files show would be what I want. However, the result is the buildings (source), but clipped to the boundary of the flood zone (overlay boundary). You can see what happened below in purple. I just want the buildings that intersect the flood zone, but not clipped. The result seems more like what the type Clip should be, not Intersect. intersection_overlay.png

 

I tried using Union, but it's basically the same thing. It splits the building along the flood zone line and creates two polygons instead of just returning the building's polygon. 

 

How can I get just the buildings that are completely within and intersect the flood zone without the building being clipped?

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