Working with CAD, Drawings and Partitions

Before we look at layouts, we need to see how CAD is used in ⁿ4ce. Unlike previous systems from AiC Ltd, CAD is at the heart of many ⁿ4ce features. It does not control the UI or the database, being just another tool in ⁿ4ce’s Geomatics Software toolbox.

CAD is used in:

• Drawings using paper space and model space viewports to create final presentations.
• To embellish Models with tables, hatching and other details, extracting points for Modelling.
• For creating general CAD detail, including symbols and plotting sections.

Note that once your data has been exported, any changes you make won't be reflected in the original source data, and changes to the source data will not be reflected in the exported file.

ⁿ4ce CAD

CAD folders are held on the Project Tree and can come from several different sources, including AutoCAD^TM (DXF, DWG, DWT) and OS Mastermap^TM GML files.  You can, of course, create a new, empty CAD folder.

When importing or exporting CAD folders, blocks in AutoCAD become symbols in ⁿ4ce and vice versa.  The main difference is that blocks can have elements drawn on multiple layers. These are flattened onto one layer in ⁿ4ce symbols.  Symbols can have an origin and up to two additional handles. These additional handles are lost when converted into a block.

When importing AutoCAD files, you will be expected to provide a scale and units. Architects generally work in millimetres (mm), so we need to convert this into metres (m) by setting the units to mm.  Since AutoCAD defines text in ground units and ⁿ4ce uses mm at specific drawing scales, you must also specify the drawing scale; otherwise, text sizes will be wrong.

If a CAD file contains a DTM, this can be imported into a Model to create the DTM as found in the source package, bypassing the need to extract points from CAD features to generate a new DTM.

A Filter option has been provided for importing historic OS Maps, where the layer name is non-descriptive, changing it from G80010001 to Building Layout. Further tools allow the changing of element colour and line style for individual layers. The Enabled tickbox must be selected for these changes to take effect.

Once you have selected the filter to apply, the Layer codes will change accordingly, as seen below.

CAD folders can be viewed in two modes. Firstly, it is a list of layers in the display window or within the graphics environment.  Editing tools are available in both views, including copying and pasting of selected layers.

When importing the AutoCAD file, you can select the Edit button (highlighted in the image above) to change the line style on individual layers.

Each Model contains a special overlay called the dedicated CAD backcloth. This is where non-survey or model details, such as curve-fitted contours, tables, hatching, and sections, will be drawn, if required.  Access is through the pencil icons if you are still using the classic UI and through the properties menu on the left-hand side of the model view in the Ribbon UI.  This acts like an overlay, sharing the layering and linked viewing.  If the model and dedicated CAD windows are open at the same time, zooming into one will automatically zoom or pan to the same location.  This is called synchronised zooming.

Plotting Sections in CAD

Sections can be created at different locations within ⁿ4ce, including section volumes, river sections, and radial sections used in visibility and section-taking tools.  These can be single or multi-profiled, long or cross.

Once created, section profiles are stored on the project tree and can be previewed.  This preview can be queried and displayed with different parameters, including drop lines, nodes, height differences etc. It's live!

Sections are plotted in CAD (model space) or a Drawing (paper space). Plotting options contain user-defined parameters, including areas and height differences between different profile surfaces. Before you have plotted the section, a preview dialog box will appear, allowing you to customise the scale and sizing of the section. 

ⁿ4ce Drawings

This is where ⁿ4ce provides tools for final presentations. The interface for this is the same CAD environment used for plotting the sections, as seen earlier. You draw in units of m, to the paper size chosen A0 (1.189x0.841), A1 (0.841x0.594), A2 (0.420x0.297) etc.

Users can create pre-defined Drawing Templates that contain title boxes, legends and north points drawn in paper space. Sections, tables and other CAD details can be drawn in this space, however, it's more likely that you would want to plot your survey and see your models with contours, etc., in model space. We have put together a step-by-step video on how best to create a Drawing Template from scratch. Click on the following link: Drawing Template

Here, we use a concept called a Viewport.  This is a “window” onto the project, which allows you to plot detail in model space at a nominated scale. It is possible to combine CAD, models, alignments, images and the recently added Point cloud option as overlays, this will help when you need to display multiple types of data simultaneously. Multiple viewports can be added to a drawing, which can then be moved or resized using the notches on the corners and mid-sides of the greyed border.  Any changes made to the original source data chosen for the viewport will be updated automatically in the viewport.  This also applies to layering.

Selection detail to be shown in a viewport is controlled using Viewport Settings.

The Viewport settings is where you would choose CAD, DTM, Alignment, Images, and Point Clouds to be overlaid. Whilst configuring your settings, ensure you press the Auto button to centre the chosen detail, otherwise it may miss the viewing window! Detail can be nudged in the viewport, whilst keeping the window in its chosen location. If your data is placed in coordinates far away from each other, it is recommended to create a new viewport for the separate data, otherwise, the data will appear far away and thus will not be in view. As you can see below, the drawing is made up of three different viewports to display different data sets.

Here we have a final presentation drawing with a viewport showing two models, one of which is lightened, a section drawn in paper space and an image taken from the 3D viewer of both models.  This can be printed and/or exported to AutoCAD. Multiple viewports are possible, so another option would be to plot the section in CAD using model space and then include this in its viewport.

ⁿ4ce Layouts

Whilst overall project plots, as seen above, are possible and a viewport can be used to zoom into specific detail at a larger scale, Layouts provide yet another option, allowing you to create Drawing templates as a large-scale cutting template, creating single or multiple Drawings, with their predefined title box and notes.  But first, a Drawing Template must be created with a single empty viewport at a nominated paper size.

An example of the Layouts Parameters dialog box can be seen below, this is where you can adjust the angle, scale and even use/add new symbols. If you have previously saved layout templates to a folder on your computer, you can access these by clicking on the Browse button (highlighted in the image) at the bottom of the Templates box.

The locating handle and direction are identified first, and here we will be using the bottom left option. We will also use a 10mm overlap, which is important when you are covering a large model, as this allows for viewports to overlap each other. Layouts can be created either in a Model or CAD.  Here, we will use a Model example with the data not being centred. The short video below demonstrates an exampleof how to adjust the position of your data.

Adjusting data position within the viewport

The image above is the original Model folder at a scale of 500, as you can see, it is not centered. The video shows how you can manipulate the viewport and its positioning, although when you are creating the Drawing, you should always click the Auto button, which will centre the data for you. Once the layout is created, it will be stored on the project tree. 

Everything is live, so any changes to source data will automatically update in the layouts.  If the image position is moved in the Drawing, the outlines of the Layout in the Key Plan will also move.

Export to AutoCAD will also pass across Model and Viewport detail, as shown below, noting that tabs provide access to viewports.