Moving Points

The Move options allow you to change the co-ordinates of points in the model.  When you move a point, this will also affect the DTM, if that point is used, and the DTM triangles will be adjusted accordingly.

Some of the options follow the current pick mode.  In these cases, you will be asked to either indicate a point to move, a rectangle surrounding the points to move or confirm that you wish to perform a move operation on the points on the Select List.

Dragging Points

The Coords Drag option allows you to move selected points using the mouse cursor and follows the current pick mode.  If the element pick mode is set, you will be asked to indicate the new position of the point.  If either of the other pick modes is set, you will be asked to indicate start and finish positions for the move.  The delta values between these two positions define the offsets through which the selected points will be moved.  Note that the start and finish positions do not need to be points but the current lock mode will be obeyed.

Moving Points by Distance in a Direction

The Coords Distance option allows you to move points in a certain direction by a given distance and follows the current pick mode.  You will first be asked to indicate two locations that define the direction of the move.  These do not need to be points but the current lock mode will be obeyed.  You will then be asked to enter the distance through which points are to be moved and then to indicate the points.  The default value for the distance is the plan distance between the two positions used to define the move direction.

Relative Move of Points

The Coords Relative option allows you to move selected points by defining values for co-ordinate offsets and follows the current pick mode.   After the points have been indicated, a dialog will be displayed asking you to enter the co-ordinate offsets.  The display will be updated to reflect changes to any features and the relative offsets are remembered for any subsequent use of this option

Note that if some of the points you have chosen to move do not have a height, the height offset has no effect and the point will remain 2D.

Moving Points to New Co-ordinates

The Coords New option allows you to move a single point to a new location.  You will be asked to indicate the point to move.  A dialog box will then be displayed allowing you to enter the new co-ordinates.  The initial values displayed in the dialog box will be the current co-ordinates of the point.  If you wish to set the point to have no height, clear the entry in the dHeight field.  The display will be updated to reflect any changes to the feature which uses the point.

Changing the Heights of Points

The Heights options allow you to change the heights of indicated points and all but one of these options follows the pick mode.

Raise - This option allows you to raise or lower the heights of the selected points.  You will be asked to enter the height offset through which the selected points are to be raised.  To lower the points, enter a negative offset.  The entered offset will be remembered for any subsequent use of this option.

Project - This options allows you to change the heights of the selected points by projection onto another line feature.  You will be asked to indicate a line feature, that must be 3-dimensional, and then the points to be projected.

To Null - This option allows you to remove the height assigned to the selected points, in effect making them 2D.  You should note that if you have formed a DTM for the current model, this option will be disabled.

To Height - This option allows you to change the heights of the selected points to a common value.  You will be asked to enter the height you wish to assign to the points.  The entered height will be remembered for any subsequent use of this option.

To DTM - This option allows you to change the heights of the selected points so that they sit on a DTM and will be described below.

From Text - This option allows you to change the height of a point to that which is contained within a piece of CAD text which is either in the dedicated CAD backcloth or a CAD model that is in the backcloth.  This option ignores the current pick mode.  You will be asked to indicate the point concerned and then the item of text.  The text that is indicated can have prefixes and suffixes to it and these will be removed.  For example, if you indicate a piece of text with the string CL=86.456m, the value 86.456 will be assigned to the point.

To Trend - This option allows you to change the height of the selected points so that they sit on a calculated DTM trend.  A DTM trend is a design tool which is a mathematical inclined plane, the equation of which is calculated from some of the points in the current model.  In n4ce, all triangular DTMs can have a DTM trend which can be used to extrapolate information outside the bounds of the DTM.  DTM trends will be described later in the chapter dealing with surface design tools.

Changing Heights to a DTM

If you select the option Heights to DTM, you will be asked to select the model from which the heights are interpolated using the dialog shown below.  The list of models to the left shows only those from which interpolation can take place.  The Preview window shows the points on the current model and the outline of model currently selected in the list.

The radio buttons in the Parameters group allow you to further define which points are to be interpolated as follows

All - All the selected points will have their heights changed.

Above Only - Only those points that currently lie above the selected DTM will have their heights changed

Below Only - Only those points that currently lie below the selected DTM will have their heights changed.

The Group Depths check box in the Parameters group allows you to take into account any depths that been assigned to the groups of the selected DTM.  If a height is interpolated from a triangle assigned to a group with a depth, the value of that depth is subtracted from the interpolated height.

Near Neighbour Heights

The Neighbour Single option allows you to change the height of an indicated point by using points that are close to it.  Firstly, you will be asked to indicate the point to move and then a sequence of neighbouring points.  The height is calculated by a weighted distance algorithm which means that those further away have less effect on the height of the point than those which are closer.