topic Re: Convert 3D points to 3D lines (underground well data) in 3D Questions

Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Mon, 25 May 2015 20:37:08 GMT

I am trying to convert the measured 3D points data into 3D lines. The data is underground vertical well data. When I am converting from points to line the conversion process is failing to capture the Z values and the lines are being drawn on the surface horizontally. I can understand the issue but I am not sure how to solve it. Any suggestions would be helpful.

Thank you.

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Mon, 25 May 2015 23:19:48 GMT

If the standard tool is not working, you could always use some Python code to create the 3D lines. The thread below shows a snippet to convert a 2D polygon into a 3D polygon (and later into a PolylineZM). Re: M for a XYZ polyline

I guess the code can be adjusted to read a 3D point featureclass and create 3D lines.

If you are willing to share some sample data I can adjust the code.

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Mon, 25 May 2015 23:49:39 GMT

Howdy Bakker,

Thank you for your direction. I will first try to develop the python code based on your link. If I am unable to solve the issue, I am willing to share a sample dataset with you. Is there any way I can send the dataset directly ?

Thank you once again.

Raghuveer

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Tue, 26 May 2015 02:59:09 GMT

If your data is classified, and you can't share it, then don't share it. No problem. It will help in order to determine if there is a field that identifies which points below to which line, the order of the points and if other attributes should be considered (also if the geometry is 3D or the Z is stored as attribute).

In case you need further assistance please specify those details and the version of ArcGIS you have installed.

If you run into problems while coding, you can post back what you have done so far and me and/or other users can provide help in fixing the code.

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Tue, 26 May 2015 13:45:01 GMT

The data is collected at various depths vertically and we have Z value attribute and other attributes as well.

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Tue, 26 May 2015 15:22:51 GMT

I am using ArcGIS 10.3

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Sat, 11 Dec 2021 21:38:28 GMT

The code below seems to be working...

def main():
    import arcpy
    import os

    arcpy.env.overwriteOutput = True

    fc_pnt = r"D:\Xander\GeoNet\3Dpoints_3Dlines\gdb\test.gdb\points3D_v02"
    fc_z = r"D:\Xander\GeoNet\3Dpoints_3Dlines\gdb\test.gdb\polylineZ"

    fld_lineid = "LineID"
    fld_order = "Elevation"

    # create a new fc Z enabled, but no M values
    fc_ws, fc_name = os.path.split(fc_z)
    arcpy.CreateFeatureclass_management(fc_ws, fc_name, "POLYLINE", fc_pnt, "DISABLED", "ENABLED", fc_pnt)

    # write the geometries to the new fc
    sr = arcpy.Describe(fc_pnt).spatialReference
    # flds_in = ("SHAPE@", fld_lineid, fld_order)
    fld_shp_in = arcpy.Describe(fc_pnt).shapeFieldName
    sort_flds = "{0} A; {1} A".format(fld_lineid, fld_order)
    flds_in = "{0}; {1}; {2}".format(fld_shp_in, fld_lineid, fld_order)
    flds_out = ("SHAPE@", fld_lineid)

    lineid = "NotSet"
    lst_poly_z = []
    with arcpy.da.InsertCursor(fc_z, flds_out) as curs_out:
        curs = arcpy.SearchCursor(fc_pnt, fields=flds_in, sort_fields=sort_flds)
        for row in curs:
            pnt = row.getValue(fld_shp_in)
            prev_lineid = lineid
            lineid = row.getValue(fld_lineid)
            if prev_lineid == lineid:
                # add point to line
                lst_poly_z.append(pnt.firstPoint)
            else:
                # write previous line and start new one
                if len(lst_poly_z) > 1:
                    polyline_z = arcpy.Polyline(arcpy.Array(lst_poly_z), sr, True, False)
                    row_out = [polyline_z, prev_lineid]
                    curs_out.insertRow(tuple(row_out))
                lst_poly_z = []
                lst_poly_z.append(pnt.firstPoint)

        # write last polyline
        if len(lst_poly_z) > 1:
            polyline_z = arcpy.Polyline(arcpy.Array(lst_poly_z), sr, True, False)
            row_out = [polyline_z, lineid]
            curs_out.insertRow(tuple(row_out))
        del curs, row

if __name__ == '__main__':
    main()

line 7 and 8 hold the paths to input 3D points and output 3D lines
line 10 holds the name of the input field that identifies the lines (for each unique value in this field points will be combined into a single line)
line 11 holds the name of the input field that provides the order of the points when creating the line (I used the same Z value)

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Tue, 26 May 2015 19:07:56 GMT

Bakker,

Finally I got permission to share some sample dataset

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Tue, 26 May 2015 22:34:39 GMT

Hi Naga Raghuveer Modala ,

I will have a look at it and come back to you as soon as possible. If I have any questions I will post them here.

BTW, my first name is Xander. You can call me Xander.

Kind regards, Xander

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Tue, 26 May 2015 22:44:35 GMT

Some assumptions and questions:

api_wellno, contains the id that distinguishes each line (in this case there are two lines)
bh_long, longitude in decimal degrees WGS 1984
bh_lat, latitude in decimal degrees WGS 1984
Z, Z value of point (although there is a measdpth too) in what unit is this? cms?
what is the field that indicates the order of the points to connect them to a line?

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Tue, 26 May 2015 22:50:29 GMT

Xander,

you are correct, there are two wells
bh_long and bh_lat represents the longitude and latitude in decimal degress.
Z values are the neg values of measdpth
The field that indicates the order is also the measdpth. Measurements were made at various depths, so the order will be the top most depth to the deepest depth.
The units are in feet.

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Sat, 11 Dec 2021 21:38:31 GMT

This is the code that you could use to convert the csv into a 3D polyline:

def main():
    import csv
    import arcpy

    # input csv
    csv_path = r"C:\Forum\3Dpnts_3Dlines\SampleData_well.csv"
    fld_x = 'bh_long'
    fld_y = 'bh_lat'
    fld_z = 'Z'
    fld_order = 'measdpth'
    fld_lineid = 'api_wellno'

    # settings
    sr = arcpy.SpatialReference(4326) # WGS_1984
    arcpy.env.overwriteOutput = True
    feetinmeter = 0.3048

    # output featureclass (could also point to fc in fgdb)
    fc = r"C:\Forum\3Dpnts_3Dlines\shp\test01.shp"

    lineids = []
    dct = {}
    # read csv
    with open(csv_path, 'rb') as f:
        reader = csv.reader(f)
        cnt = 0
        for row in reader:
            cnt += 1
            if cnt == 1:
                # header
                header = row
            else:
                # read fields from data
                lineid = row[header.index(fld_lineid)]
                x = float(row[header.index(fld_x)])
                y = float(row[header.index(fld_y)])
                z = float(row[header.index(fld_z)]) * feetinmeter

                # create point object with XYZ
                pnt = arcpy.Point(x, y, z)

                # read order and create string to sort on (lineid + order)
                order = row[header.index(fld_order)]
                srt =  "{0}_{1}".format("%04d" % (int(lineid),),
                      "{0}".format(round(float(order), 1)).zfill(8))

                # create nested dictionary with points per line
                if lineid in dct:
                    dct[lineid][srt] = pnt
                else:
                    dct[lineid] = {}
                    dct[lineid][srt] = pnt

    # create polylines
    lst_polylines = []
    for lineid, dct2 in dct.items():
        lst_pnt = []
        for srt, pnt in sorted(dct2.items()):
            lst_pnt.append(pnt)
        polyline = arcpy.Polyline(arcpy.Array(lst_pnt), sr, True, False)
        lst_polylines.append(polyline)

    # write polylines to output featureclass
    arcpy.CopyFeatures_management(lst_polylines, fc)

if __name__ == '__main__':
    main()

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Wed, 27 May 2015 14:32:19 GMT

Xander,

Thank you very much. The code is working great. I just made minor changes to the code. I removed the conversion factor to fit to my requirements. The output is decent and satisfactory to most extent. when the line curvature exists the points and the line doesnt align properly though.

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Sat, 11 Dec 2021 21:38:34 GMT

A small explanation of what is going on, on line 44 and 45:

srt =  "{0}_{1}".format("%04d" % (int(lineid),), 
       "{0}".format(round(float(order), 1)).zfill(8))

It creates a string combining the lineid (e.g. 102) and the order (e.g. 5482.0) into a string that will be used as key for the dictionary. The dictionary is sorted on key (see line 58) and the string "srt" will have a value like: "0102_005482.0". This allows to sort on line and per line on order.

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Thu, 28 May 2015 14:05:18 GMT

I am trying understand this code. When i apply the same code with slight modifications to different set of data. It isn't working correctly. The new data has a lineID of 14 characters and the order varying from 3 to 5 characters.

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Sat, 11 Dec 2021 21:38:37 GMT

if the lineid is always 14 characters, or if it is not numerical you could simply do this:

srt =  "{0}_{1}".format(lineid, 
      "{0}".format(round(float(order), 1)).zfill(8))

It is probably not important in which order the lines are processed. What is important is the order of the points per line being processed.

Re: Convert 3D points to 3D lines (underground well data)

Naga_RaghuveerModala — Thu, 28 May 2015 15:23:03 GMT

Xander,

Whoop! Its not the code I had problem with. its the format of my CSV columns. After fixing that issue everything looks great. Thank you very much Xander for all your help.

Re: Convert 3D points to 3D lines (underground well data)

XanderBakker — Thu, 28 May 2015 19:09:47 GMT

Glad it works now. The fields are hard coded...