introduction to computer cartography for better or worse the day the day of hand drawn computer maps...

For better or worse the day the day of hand drawn computer maps

is coming to a close

Computer Cartography is quickly replacing it

There are a LOT of reasons for this:

- Better and cheaper computers

- Easy and powerfull Software

- Access to good color printers

- Easily accessible formats (JPEGs, PDF) to share data and maps

-

And the maps themselves!!!:

- Better Lineweight control

- Color!

- Typesetting

And most of all

- Correctable

- Updateable

A quick overview of Computer Graphics

Raster Graphics

Raster Graphics is a grouped collection of individual dots (pixels)

When areas are picked and moved, everything goes. There is no difference between different parts

Vector Grapics

In vector graphics, shapes and lines are described by formulas

So individual features can be moved as a whole

Some popular graphics programs :

- Freehand

- Corel-Draw

- Autocad

- Xara

- Macpaint

- MS Paint

Vector based software Raster based software

So lets go through drawing a basic map in a graphics

The first step, as for hand drawn maps, is to take your data and reduce to a line plot

Compass

Using ‘normal’ hand drafting techniques, cover the lineplot with mylar and pencil in your details

Scan your hand-drawn draft into the computer. Just about any format is ok – JPEG for example.

Make sure that you scan at enough resolution to capture all your detail!

If you cannot get the entire hand draft onto the scanner at once, scan in sections – make sure there is enough overlap!

Import your scan into your graphics program – in this case Illustrator, and assemble the scans in the correct order

Import using place and highlight your scan

Place as many as you have

Using the pointer, highlight your scans and drag them until they overlap correctly

You can rotate the scan if they need to be rotated

A few words about layers

•Layers are one of the best features of a graphics program, and most (if not all) modern products have layers

•Layers act like separate pieces of mylar. You can draw on several pieces and then combine them together for the whole

•We use layers to separate types of features, to make it easier to work on specific groups at a time

•We tend to use separate layers for • Walls• Structural • Details• Typesetting• Scan• Among other things

You can Lock the layer so it doesn’t move, or get changed

You can make layers invisible, or show them. Making layers invisible can help you work on other layers

Make a new layer with this button

By Default your scans will go into layer one. Click on it, and an options box will appear. Rename it to base or scan, and dim it to 75%

Now lock it

Click here to make new layer

Call it walls

Should look something like this

You can change the zoom here – zoom in a bit

Make sure the walls layer is highlighted (so you draw in it)

Set the Stroke width to 1.5 pt (for the walls)

Pick up the pencil tool

Set to no fill

Start to Draw, tracing your hand drawn map!

Continue your tracing of the walls – making sure you get all of them.

A few hints

- If you stop drawing, you can restart by putting your pen over the end of a highlighted section

- Zoom in enough to see all your detail clearly. You can use the zoom button

- You can move the drawing around with the hand button

- Create a layer called structure

- Change the pen width to 1pt

- Zoom in to make sure you see the detail clearly

- Make sure the structure layer is highlighted

- Pick up the pen and start drawing!

Do the same thing with details!

A finished map may have many layers