Inserting New Points

The Insert option from the Points Menu allows users to create new points in a variety of ways. When selected, the dialog box shown below is displayed.     

The Insertion Method group defines the calculation method for the plan position of the new points.  Each method requires users to indicate different reference data. 

The Height Calculation group defines the calculation method for the height of any new points. Some of these methods are not valid for all insertion methods.

The Parameters group displays the basic data for inserting new points. The 'Point Code' field displays the code that will be assigned to new points. The default values in the drop-down are the available code prefixes and underneath is a text string which displays the description of the current code prefix. The Start Point Number defines the point number of the first new point with subsequent point numbers being incremented. 

The Add Point Attributes tool allows additional details to be added to the points once they are generated. This link explains in more detail.

Prefix Created Points: This checkbox enables users to add a point number prefix of 'I' to each new point. This feature is used to distinguish the points added by users and the ones that were already present or imported into n4ce.

Plan Chainage becomes active when using the 'Distance along' option. It generates the necessary point at the given plan distance, rather than using the given two points to work on a slope distance instead.

As long as a DTM exists in the current Model, the height of the new point is not null and the point is inserted inside the extents of the current DTM. Then Insert into DTM will automatically include the point into the current DTM surface once it has been generated.

Auto Close Lines adds a, P to the first point of inserted points that use a code that draws a line feature.  This then closes the line feature automatically once it contains 3 or more points.

Continuous Insert will keep the current insert method going until users right-click and cancel.

Add to List check allows you to add all new points to the point list.

Fix Recently Used as Favourites allows users to set a list of Favourite codes to easily access them.

Clear - Load - Save are options used to manipulate the Recently Used/Favourites list. Clear removes all codes from the list. Load re-loads the saved list. Save creates a copy of the recently used list as Favourites.

Inserting the Point

When a point is inserted into the model, a new dialog window will appear allowing users to easily adjust/add dimensions and any extra information.

Code: The code entered at the previous stage.

Comma Codes: Any Comma Code that users would like to add to the new point e.g. C / T.

Remarks: Allows users to add extra details they want to store on the point.

Dimensions Field: This window is populated by the fields set up on the code. Users can then edit these values if necessary. The options below allow for different ways the dimensions can be inserted. Entered Values - Uses the values entered. Default Values - Uses the preset values set within the fields Tab within the code table. No Dimensions - Leaves the Entered Field blank. 

Calculating the Location of New Points

The Sketched method will insert points based on the current position of the mouse cursor. Each time users click on the left button of the mouse, a new point will be created. They can use the Lock Mode setting to ensure that points are placed in locations coincident with anything displayed in the backcloths, for instance, the ends of lines or corners of buildings. For this method, the Relative and Linear Interpolation height calculations are not available.

The Relative XY method allows users to insert a series of points relative to an existing reference point.  They will be asked to indicate the reference point and then use a dialog box to enter the offsets, as shown below. Each time they select the OK button, a new point will be created and the dialog box will be redisplayed using the previously entered offsets as the defaults. For this method, the Linear Interpolation height calculation is not available.

The New XY method allows users to create a series of new points by typing known coordinates. A dialog box, like that above, will be displayed allowing them to enter a series of new point coordinates. Each time the OK button is selected, a new point is created and the dialog box will be redisplayed with the previously entered coordinates being used as the default values. For this method, the Relative and Linear Interpolation height calculations are not available.

The Angle & Distance method allows users to create a series of points by entering an angle and a distance. Firstly, users will be asked to indicate two points which form a reference line. Users will then be asked to enter a series of angles and distances using a simple dialog box. The angle is the angle from the reference line to the new point and the angle convention is that clockwise from the reference line is positive. The angle should be entered in the angle units set in the current defaults. The distance is the plan distance between the new point and the first point of the reference line. The Relative height method will calculate heights based on the first reference point. The Linear Interpolation height method will calculate heights based on a linear interpolation of the entered distance along the reference line.

The Bearing & Distance method allows users to create a series of points by entering a bearing and a distance. Firstly, users will be asked to indicate a single reference point from which all calculations will take place. Then they will be asked to enter a series of bearings and distances using a simple dialog box.  The bearings should be entered in the angle units set in the current defaults. The distance is the plan distance of the new point from the reference point. The Relative height method will calculate heights based on the reference point.  For this method, the Linear Interpolation height method is not available.

The Distance Along method allows users to create a series of points that are at known distances along a reference line. Firstly, users will be asked to indicate the two points which form the reference line and then they will need to enter a series of distances using a simple dialog box.  The distances entered should be that from the first point on the indicated reference line. For this option, the Plan Chainage check box becomes visible but will only be enabled if the Linear Interpolation height method is set. If checked, the distance entered will be assumed to be the plan distance to the new point.  If it is not checked, the distance will be assumed to be the slope distance to the new point. The Relative height method will calculate heights based on the first point and the Linear Interpolation height method will interpolate along the indicated reference line.

The Points Along method allows users to add a fixed number of points between two reference points.   They will be asked to indicate the start and end of the reference line and then enter the number of points to be created using a simple dialog. Only the Linear Interpolation height method will be available for this insertion method.

The Chain & Offset method allows users to calculate the position of points that are a known distance along and a known perpendicular offset from a reference line. Firstly, users will be asked to indicate the two points which form the reference line followed by a series of chainage and offset pairs using a simple dialog box. The convention for the offset is that 'negative' is to the left of the reference line, as shown in the example, and 'positive' is below. For this option, the Plan Chainage check box becomes visible but will only be enabled if the Linear Interpolation height method is set. If checked, the distance entered will be assumed to be the plan distance to the new point. If it is not checked, the distance will be assumed to be the slope distance to the new point. The Relative height method will calculate heights based on the first point and the Linear Interpolation height method will interpolate along the indicated reference line.

The Tied Distances method allows users to calculate the position of points that are of a known distance from two reference points. Firstly, they will be asked to indicate the two reference points followed by a series of distance pairs using a simple dialog box. Checks are made to ensure that the entered distances are valid. They are valid if the sum of the two is more than the distance between the reference points and the difference between the two is less than the distance between the reference points. The convention on whether the calculated point is to the left or right of the reference line is based upon the sign of the distance from the first point. If this distance is negative, the point will be to the left, as shown in the example. If it is positive, it will be to the right. The Relative height method will calculate heights based on the first point and the Linear Interpolation height method will project the calculated point onto the reference line and linearly interpolate using the projected position.

The Perpendicular Offsets method allows users to insert points that are perpendicular to a reference line that changes after each new point is created. Firstly, they will be asked to indicate the two points which form the first reference line followed by a series of perpendicular offsets using a simple dialog box. In this way, users can generate a building outline from one side and the lengths of the other sides which have been measured using a tape.

In the example shown above, the first calculated point, 3, is calculated by using the indicated reference line points, 1 and 2. The second calculated point, 4, will then be calculated using the first reference point and the first calculated point, 2 and 3. The third calculated point, 5, will be calculated using the first and second calculated points, 3 and 4. The convention for the offset is that a negative offset will create the point to the left of the current reference line. Note that for the first calculated point, it is the first point on the reference line that is used. For the second and subsequent points, it is the second point on the reference line that is used.

The Bearing Intersection method allows users to calculate a point that is of known whole circle bearing from two reference points. Firstly, they will be asked to indicate the two reference points followed by a series of whole circle-bearing pairs using a simple dialog. The bearings should be entered in the angle units set in the current defaults. A check is then made to ensure that the lines created by the reference points and the entered bearings intersect. The example shown below shows an invalid pair of bearings, where they diverge, and a valid pair of bearings, where they converge. For this method, the Linear Interpolation height calculation is not available.

The Parallel Bearing & Dist option allows users to calculate a point that is a known distance from a reference point at a bearing that is defined by two further points. Firstly, they will be asked to indicate the reference point followed by the two points that define the bearing to use. They will then be asked to enter a series of distances from the reference point at which to create the new points using a simple dialog. In the example shown below, point 1 is the indicated reference point, points 2 and 3 define the required bearing and points 4 and 5 are the new points that have been created at a known distance from point 1. For this method, the Relative height method will use the reference point for its calculations whilst the Linear Interpolation height calculation is not available.

The Sphere Centre option allows users to calculate the point at the centre of a sphere defined by four other points. They will then be asked to indicate the four points in turn. The points must be 3D and, since the height of the new point is calculated in the algorithm, all height calculation methods are disabled.  This insert method is used for registering scanned data.

The Four Point Intersect method enables users to calculate the point at the intersection of two reference lines. Firstly, they will be asked to indicate the four points that make up the two lines. The first and second points will be assumed to be the first line whilst the third and fourth points will be assumed to be the second. For this method, the Relative and Linear Interpolation height calculations are not available.

Clipboard Wait is documented here.

Fit Circle Centre generates a new point by best fitting a circle by indicating 3 or more existing points and then placing the point at its centre. If the code used plots a 1pt circle or 1pt Diameter circle, then the attribute added to the point will draw the correct circle as a result.

The 3d Circle Centre option takes three existing points as input and inserts a new point. The three indicated points must be 3D and fit a 3D circle to it, ie in the plane defined by the 3 points. An attribute R3 is then added to the point which is the radius of the circle on the plane.

The Height of New Points

The Height Calculation group defines the method by which the height of any new points is calculated.  These are as follows.

Typed: For each new point, users will be asked to enter a value for the height. If no other data is required, a simple dialog box asking for the height will be displayed, if more information is required, users will be prompted to input values into the same dialog box.

Relative: Each new point height will require a relative height offset from the first reference point that is indicated.  Where possible, the value of the height offset will be asked for in a dialog box that is asking for other required data.  If no other data is required, a simple dialog box asking for the height offset will be displayed.

Null: The new point will not be given a height and will be assumed to be 2D.

Constant: The Constant Height field in the Parameters group will be enabled for this option. Each new point will be assigned this value in this field.

Linear Interpolation: The height will be calculated by linearly interpolating between two of the reference points.

Near Neighbour: As each point is created, users will be expected to indicate a series of points which are neighbours to the new point. A weighted distance algorithm is then used to calculate the required height. The further an indicated point is away from the new location, the less effect it has on the height.

Model Interpolation: The Reference DTM combo in the Parameters group will be enabled for this option. The coordinates of the new point will be used to interpolate a height from the selected DTM.

Above DTM: The Reference DTM combo in the Parameters group will be enabled for this option. A  height will be interpolated using the coordinates of the new point and users will then be asked to enter a height offset which is added to this. Where possible, the value of the height offset will be asked for in a dialog box that may also require more data. If no other data is required, a simple dialog box asking for the height offset will be displayed.

Constant Above DTM: The Reference DTM combo and the Constant Height field will both be enabled for this option.  The coordinates of the new point will be used to interpolate a height from the selected DTM and the value in the Constant Height field will be added to this.

Model Trend: The Reference DTM combo will be enabled for this option and will list all the DTMs that currently have DTM trends created within them. This DTM trend is then used to calculate the height.

Indicated Text: As each point is created, users will be asked to indicate a piece of text which is in the CAD backcloth containing the point height. The indicated text can have prefixes and suffixes to it and these will be removed. For example, if users indicate a piece of text with the string CL=86.456m, the value 86.456 will be assigned to the point. This method is only available with the Sketched insertion method.