Save your data!

Drawing in Map Maker
Drawing in Map Maker

It is really easy to start drawing in Map Maker.  Simply select a tool and start drawing. More tools are visible in the Context Menu (right click, select Draw).

When you trace a polygon from an aerial photo, you are not drawing on the image itself, as you would in Paint, but creating a new vector data set.

In Map Maker you draw in the Live Layer and only in this layer.  You do not draw on any of the other layers, as in Photoshop or Illustrator.

This turns out to be quite useful, as it stops you from inadvertently adding data to a different layer than intended – e.g. corrupting a core data set.

The Live Layer is empty until you start drawing on it.

You can load previously saved data set into the Live Layer, any vector data set or transfer data from an existing layer.

Before long you will want to save your hard work.  There are several options for saving it and this is where some discipline is required.  In Map Maker you save your Live Layer data in Map Maker’s native format (.dra).  You can export .dra data to other formats via Utilities, but for now we are going to stick exclusively with the .dra format.

Save your  Live Layer Option 1: right click and select Save Live Layer As.  Remember to store all your data in your own project working space (away from core data), creating sub directories to keep all your associated files in one place.

Save your  Live Layer Option 2: in the layer bar (the left hand vertical one) hover over the small white circle to reveal the Live Layer options.  Select Save Live Layer As

Save your  Live Layer Option 3: most Live Layer options can be found in the edit menu.  Select Save Live Layer

Once you’ve saved your first set of lines or polygons, you’ll notice that a new layer is created with the same name you selected for the save.  Also, the Live Layer is emptied on save, even though you may not have finished the job in hand.

If you are drawing within a project, you may need to Save Project to see the new layer.

To add more data to the new layer you must either transfer it back to the Live Layer (Copy to Live Layer or Load file into Live Layer), or simply add data to the  Live Layer as before and then Append it to the previously created layer (Add Live Layer to).

Two further options exist: save your new data as a separate layer entirely with a different name and join them up later,  and/or transfer the layer back to the Live Layer, but then save the data with a new file version, starting from e.g. my-new-layer-001.dra, and increase the number on each save.

Depending on your working preferences, the complexity of the task in hand you have 2 main options for managing new layers: versioning (using incremental file names) or creating discrete layers (to review and merge later).  You don’t have to over do it.

Always be disciplined about saving data and projects and store new information in your own project space (it is easy to lose your data from one session to the next in the Windows folder labyrinth).

Important Notice

Save Live Layer has a number of Edit options, which must be set – or you will tear your hair out in frustration.

Edit > Live Layer Options > Save Options select “prompt to save the live layer” should your clear a project or exit.  Select the last option to save the database at the same time.

Frustration will be caused by:

  • Using Clear Live Layer to end a drawing session – it will NOT always prompt you to save.
  • saving a Project believing it will also save the Live Layer – Projects are just list of file references and until you save the Live Layer it cannot be referenced by the Project
  • saving a Live Layer and it fails to transfer to a fully fledged Layer on screen – an intermittent Map Maker bug – if this happens, beware of saving a blank Live Layer over your previously saved layer – the software prompts so think first and don’t erase your hard work!
  • drawing after an error has occurred.  Always always save your work and restart the program, before drawing if you’ve experienced any strange behaviour with Map Maker!

Thankfully, Live Layers are recovered after a crash, but if other errors keep recurring save everything, exit and start the program again.  Or start the layer from scratch.

Layer theory

All Map Maker projects use Layers, transparent sheets of data overlaid one upon the other.

Layer Types
Layer Types

A map project can be thought of as a combination of several layers, arranged and styled in a particular way and ready for use in the field, for a presentation or for publication.

A layer on the other hand is simply a data set, with or without an underlying database, with or without styling.  A map project has a context, whereas the data may have only limited contextual information associated with it.  In other words a layer comprises a discrete set of data rather than a finished map.

Map Maker like other GIS packages uses 2 main types of map data:

Vector: polygons, lines and points, defined by a set of coordinates (x and y). Map Maker uses it’s own native format to save these data identified as .dra

Raster: digital images i.e. made up of pixel squares and save in any number of picture formats, which are not specific to Map Maker.   Most Raster data will come as a collection of tiles either maps, air photos, satellite imagery or a digitally derived data set.

In Map Maker, unlike some packages, mixing vector types within a layer is possible, but we do not recommend it.  Text and arrows are another Vector type in Map Maker, but more of this later when we talk about editing Vector data.

Raster data needs a little more information than is available in the digital image alone for it to be useful in map presentations.   Co-ordinate information is held separately in a so-called “world file”, which will have been saved alongside the .tif images as a .tfw. Without co-ordinate information, it is impossible to create tiled views or overlay other data sets correctly.  If your tiling is not working, the .tfw may be missing or corrupted.

Finally, it is possible to import a number of non-native data sets into Map Maker.  The most common one, is the .shp format (by ESRI the Makers of Arc GIS).

Map projects can combine Map Maker’s .dra format, with Arc layers (.shp) and digital image files (.tif).  It is possible to convert files from format to the other, and in some instances – large data sets – it is highly advisable to convert .shp into .dra. There are Utilities available to do this along with image manipulation.

Projects

While you CAN get by in Map Maker without using Projects for a while, before long creating maps from scratch becomes a chore even if you only work from a small number of base projects.  If you are new to mapping software, projects are neat as they let you explore other’s maps and data more readily.

The Map Maker Project Manager
The Map Maker Project Manager

Projects have a .geo file extension and store a set of file references (your data) and important details, i.e. the styles associated with your project.

When you open up Map Maker it is configured to read in 4 OS map base layers covering a range of scales below 1:50k.  The  layers are configured to drop in and drop out of view depending on your zoom level.  You can change the behaviour to suit or remove any superfluous layers. More about this later.

Use any project as starting point for your own work, but remember first to give your new project a unique name and store it in your own personal space.  To see what projects are available  File > Open Project and then Browse if the recent file list is incomplete.

To start your own project from new, File > New Project gives you the option of using the information in a directory or folder or from a .dra file (the native Map Maker format for vector map data).  More about this later.

In Map Maker the Space Bar is used to invoke the Project Manager that we’ll use throughout this exploration of Map Maker.

*** Things to remember ***

Never save or overwrite any core project files or anyone else’s for that matter – create your own as soon as you start work.

You can only work on one project at a time.

If you keep losing style information or default styles get over-ridden, you are probably not saving projects correctly or need help with styles.

When you are working within a project, but say annotating a map layer it is easy to neglect saving your project while you are focused on your .dra layer.

It is easy indeed too easy to clear your project without Map Maker prompting you to save.  Frustrating, so save projects regularly.

Templates are edited like projects, and will clear a current project.