AutoCAD Map 3D General Discussion

AutoCAD Map 3D General Discussion

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Member
Piet22
Posts: 5
Registered: ‎05-14-2013
Message 1 of 10 (191 Views)

Manually redrawing 19th century raster maps

191 Views, 9 Replies
05-14-2013 12:41 AM

I am new to Map 3D. I have to redraw 19th century raster maps that cannot be vectorized automatically.

The borders of the parcels are heavily curved.

I insert the raster map and start to trace/draw on a new layer.

 

1. Now, if I want to draw a second parcel that has a common curvy border with a first parcel how do I best trace the common border? What I would like is that the vertices along the common border are all displayed so I could just click them rapidly to draw the common border of the second parcel. However I cannot find a way to display all vertices. Is there a solution for this?

 

2. For drawing a new parcel alongside multiple existing parcels, a beter/faster option would be that I just click the vertices on junctions of the common border and the software would automatically trace the line between the junctions, create all vertices and snap them to the existing vertices on the common border of the existing parcel. Is there a solution for this?

 

Thanks,

Piet

*Expert Elite*
antoniovinci
Posts: 1,681
Registered: ‎06-03-2011
Message 2 of 10 (184 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 01:18 AM in reply to: Piet22

You don't need to draw the common border, since Autocad Map does it automatically.

When you end the raw vectorization:

  1. first perform a _MAPCLEAN procedure, with "Break crossing objects" and "Dissolve pseudo nodes" actions
  2. then _MAPTOPOCREATE a polygon topology
  3. finally _MAPCLPLINE to generate closed polylines for every parcel
Member
Piet22
Posts: 5
Registered: ‎05-14-2013
Message 3 of 10 (174 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 02:20 AM in reply to: antoniovinci

Many thanks, this could be a perfect solution!

 

Some new questions now if I may?

 

1.

"breaking crossing objects" breaks the common border away from parcel 1 and makes it a separate polyline.

"mapclpline" closes the parcels 1 and 2 along this separated polyline.

The separated polyline is not removed after that, so the common border has now 3 lines on top of each other.

Is this OK? Should I remove this separated polyline afterwards?

 

2.

Sometimes after reviewing the results some adjustments must be made to the position of some vertices.

If I click a vertex on the common border of parcel 1 and move it, the underlying vertex of parcel 2 does not move with it. All my Osnap options are on. How can I set Autocad to make all snapped vertices move together?

 

3.

What exactly is the difference between a node and a vertex? If I click a vertex/node and move it, Autocad calls it a vertex but "maptocreate" calls the same item a node?

 

Thanks again

 

Piet

 

 

 

 

 

*Expert Elite*
antoniovinci
Posts: 1,681
Registered: ‎06-03-2011
Message 4 of 10 (163 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 03:33 AM in reply to: Piet22

Answer #1

The command _MAPCLPLINE allows you to create the closed polys on a new layer, so you can easily freeze the layer containing the manually drawn border.


Answer #2

Use the _STRETCH command instead.


Answer #3

I think "node" means "centroid", but let's wait for an Autodesk specialist opinion...

Valued Mentor
parkr4st
Posts: 451
Registered: ‎03-24-2004
Message 5 of 10 (159 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 03:41 AM in reply to: Piet22

Peit

 

vertex

A location where edges or polyline segments meet.
 
node
A type of object snap that locates point objects, dimension definition points, and text origin points.
 
topology

A set of geometric relationships between drawing objects, including links, nodes, and centroids. Topology describes how lines, nodes, and polygons connect and relate to each other, and forms the basis for advanced GIS functions such as network tracing, spatial analysis, buffer analysis, overlay analysis, and dissolving a polygon topology.

 
In AD help, Contents tab learnAutoCAD Map 3D list is glossary.  You can check there for the definiton of terms
 
you can move multiple stacked vertex by selecting with a window over the vertex point. then all will move together
 
another option for what your doing is to have two dwg layers, draft and polygons.  draft on the draft layer , switch to the polygon layer and use Bpoly command to draw the polygons.  -boundary is now the command.  Bpoly still works from the command line and a search in help for Boundary will explain the process.
 
dave
Member
Piet22
Posts: 5
Registered: ‎05-14-2013
Message 6 of 10 (158 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 03:42 AM in reply to: antoniovinci

Hi,

 

Answer #1: OK

 

Answer # 2: I think I use "stretch". If I click the vertex, the command line shows "stretch" and the little menu near the arrow shows the options stretch vertex/ remove vertex/ add vertex. However, when I drag the vertex the underlying vertices do not move with the upper vertex. If I type "stretch" in the command line Autocad wants me to select objects; however I do not want to move objects, only vertices.

 

Answer #3: OK

 

Many thanks again!

 

Piet

Member
Piet22
Posts: 5
Registered: ‎05-14-2013
Message 7 of 10 (157 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 03:44 AM in reply to: Piet22

Thanks Dave, will experiment.

 

Piet

*Expert Elite*
antoniovinci
Posts: 1,681
Registered: ‎06-03-2011
Message 8 of 10 (149 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 04:00 AM in reply to: Piet22
The _STRETCH command requires a selection from right to left onto the stacked vertexes...
Member
Piet22
Posts: 5
Registered: ‎05-14-2013
Message 9 of 10 (137 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 07:10 AM in reply to: antoniovinci

Hello Antoniovinci and Dave,

 

Your methods both work well so my original problem is now almost solved.

Almost because I am not completely happy with the fact that each method leaves an unclosed polyline behind.

The solution of adding the results of the operation to a new layer works fine if you do the operation only once but I work on maps with more than 1000 parcels so I tend to work step by step. Every 50 parcels or so i would like to perform the operation and then the results of the previous steps are also left behind on the layer with the unclosed polylines. Is there a method to delete all unclosed polygons? I think this would make me completely happy.

 

Piet

*Expert Elite*
antoniovinci
Posts: 1,681
Registered: ‎06-03-2011
Message 10 of 10 (128 Views)

Re: Manually redrawing 19th century raster maps

05-14-2013 08:03 AM in reply to: Piet22

As said before, you should create the topology AFTER the complete manual vectorization.

Once the polygon topology is correctly generated, you get INSTANTLY all the closed polylines thru _MAPCLPLINE.

In other words: the tedious work is to draw the old scanned paper, while the clever finishing belongs to the powerful tools of Autocad Map.

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