Feature Coding Examples

The following are samples of how you may use the coding systems identified in the article, Code Table and Feature Plotting.

Example 1 - Using Line Features for Road Marking

If you wish to pick up the start and ends of dashed lines, use the Alternate Segments option in the Lines tab.  Another option here, is to use a dedicated line Style set up for road markings, as shown above.  The sizes given are real sizes in mm.  For example, the line style 1000x1000x250 gives a solid repeat line 1m long, 0.25m wide with a gap 1m.

Example 2 - Using Requested Symbols

In the example shown above, a gulley is placed at points 2 and 4, using 1Pt Requested and the comma code ,S.  The gulley takes the alignment from the feature and is directional.  If the line is reversed the gulley would appear on the bottom of the line.

Example 3 - Changing Codes Using N= or / (Import Only)

When you are picking up detail and wish to change a feature code without a duplicate point, the dimension N= can be used, as indicated below.  At Pnt# 4 a dimension N=GT is used to change the code to a gate.  At Pnt# 5 an N=HE is used to start a hedge.

In the dimension dialog you will find Code Separators / and \.  The N Dimension can be replaced by the / character and the M Dimension by the \ character, but ONLY when the Code Import Convention is set to either AiC (Dim Labels) or AiC (No Dim Labels), and ONLY when Importing files. This forms part of the code import. eg FE/GT.

Coding for Pnt# 4: FE/GT and Pnt# 5: GT/HE and no Dimensions are required.  ⁿ4ce will convert these into N= when importing codes.

Example 4 - Changing Codes Using M= or \ (Import Only)

The M= dimension is ideal for changing the next segment and then continue with the same code.  The example shown below is for a gate but it could easily be adapted for drop kerbs.  M=GT on point 4. The code for the string is still HE, so ordering will not affect the string.

Code Separators \ will work when importing data.  For example at Pnt#4: HE\GT.

Example 5 - Line Widening/Tapering

The dimension W= is used to control the width of lines features, like hedges and dual lines.  In the case of hedges, you need to set the Line attributes to Width Scaleable.  Also, note the option to offset the width half its width, so you can survey a hedge from one side instead of its centre.  Negative widths offset to the left and positive to the right in the direction of the line.

Only a limited number of lines are width scalable.  If you turn off the width scaling, the W= dimension will create twin lines.  A further attribute can taper variable widths, as shown below.  Additional options are available using the parallel offset dimension P= and setting different line styles using FPL= and FCL= for defining a centre line.

Example 6 - Line Formations

There are situations where survey detail can only be collected using tapped measurements, as access or line of sight is restricted.  Here we have another dimension called LF=.  The direction and length of the offset from a fixed baseline is governed by pairs of numbers.  The first number defines the direction as identified above.  Pairs of numbers are separated by spaces, commas, a slash or hash character.  For example LF=0,4.5,-2,1.5,2,2.5,2,1.5.  The underscore character identifies the direction.

Example 7 - Text Labels

Along with Height, Code and Number annotation, general Text can be added to a point by activating the Text tab in the code table, and/or using the T= dimension.  If the text item is in the display window as shown above, it will be displayed according to the alignment option.  The T= dimension, if present, will overwrite the contents of the Text window.  A special option called 3 Point Text, allows you to pick up road labels as shown above.  Also see below.

Example 8 - Road Markings

There are several options for plotting symbols, all identified in the Symbols tab from the code table under Type.  We’ve already seen how to plot different line styles, but here we will identify arrows.  The same of course would apply to text labels, stored as symbols.  Here is an example of a 3 point arrow symbol showing a split in the road.

Symbols need to be drawn in CAD, either in ⁿ4ce or imported from AutoCAD as a block.  If importing, then the symbols need to be exploded and reformed to generate the additional handles.  Please note the direction of the points as this will generate a mirrored symbol, if incorrectly sourced.

Example 9 - Centre Point Annotated Shapes

There are several ways of plotting Shapes used to display manholes and other regular objects like lampposts.  One of the options you may wish to consider is a 3Pt Rect Cnt, which allows you to locate and size a man hole with three points, using the first point for its level.

This could be used with Hide Second Points to remove all detail attached to the 2^nd and 3^rd points.  Alternatively, enable On First Point in Heights, Numbers or Codes.  In the example shown above, point numbers were plotted on each point and the height on the first point, with the 3Pt Rect Cnt.

Example 10 - Hash codes (#)

The examples shown above of adding an additional code to a point using the Dimensions N= and M=, can be further expanded using Hash (#) coding.  Like \ and / coding, this ONLY works on imports and involves using multiple codes assigned to a point, delimited with a # character.  For example, the code BB1#TB5#FE will provide additional links to the source point BB1, to TB5 and FE.  ⁿ4ce will generate additional observations or coordinates for the # codes.   The import conventions previously discussed for Dimensions and Comma Codes still apply. e.g. E_W_1.2#GT. (Where _ is a space character).  Here, a hedge with a width of 1.2m will be joined to a gate.  Auto Stringing also works with this option.

Example 11 - Appending Observations into a Model and Merging Models

There may be instances where you have created a Model and wish to update this with further survey detail.  This may arise from doing a survey piecemeal, creating and editing a Model as each day progresses, or returning to a site say a year later to do an update.  Whilst there is an option to create a Model by combining two others, it adds unnecessary Models to your Project.  A far better way is to copy the reduced observations and paste them into the model.  This is done from the RHS display window, not the Project tree, by right clicking over the Observations folder name and selecting Copy, then Pasting these into your Model.  All the coordinates in each setup for this folder will be copied over.  If a DTM is present from the original model with contours, you will have to delete the original and reform the DTM and contours.

If the new survey is a revision rather than an addition to the original survey, it would be better to use the Merge model option (Pro & Designer).  You will be required to form a separate model of the new survey with a DTM.  Then select the merge option from New models, cutting the new survey into the original.  This uses the DTM boundary from new model to cut into the original, removing both points and triangles.  This is ideal for keeping the original triangles and contours where no changes have been made.