One Quick Example

From Fs_wiki

(This is a work in progress. Please feel free to correct any factual errors or embelish any points which are not clear enough).

This section of the tutorial will walk you through the drawing up of a complete cave survey using Tunnel. This might seem like it should be at the start of the tutorial, but it is important that you already understand how to manage survey data and use the drawing tools in Tunnel. So if you have skipped those sections of the tutorial you should go and read them first, do some practise drawing and then come back here.

1 Before You Start
2 Starting A New Tunnel Project
3 Creating A Sketch
- 3.1 Importing the centreline
- 3.2 Loading the background sketch
4 Navigation

Before You Start

Before you can start to draw up a survey, you will need the following:

The survey data for the cave (in the form of a Survex data file).
A plan sketch of the cave survey done to scale over the cave centreline, scanned in as a bitmap file (PNG, JPEG, BMP, GIF).

You might have several sketches of different parts of the cave. We will assume for this simple example that you only have the one sketch.

This example will use the following items, which you can copy off this page to use too if you do not have your own data at this time.

*begin examplecave
*entrance 001
*fix 001 3234 4231 352

;Cave:	Made up example cave for Tunnel Quick Example
;Date:	11/05/2006 Footleg

;From	To	Tape	Compass	Clino		L	R	U	D
001	002	3.28	012	-25		;0	0	0	0
002	003	2.33	353	-2		;0	0	0	0
003	004	1.88	005	0		;0	0	0	0
004	005	3.73	028	+6		;0	0	0	0
005	006	9.59	016	+36		;0	0	0	0
006	007	17.44	302	+29		;0	0	0	0
007	008	4.34	314	+2		;0	0	0	0
008	009	12.42	284	+4		;0	0	0	0
006	010	5.98	106	-8		;0	0	0	0
010	011	2.64	053	-2		;0	0	0	0
006	012	8.42	007	+7		;0	0	0	0

*end examplecave

Example Cave Sketch

Starting A New Tunnel Project

Now we are ready to start using Tunnel. Launch the Tunnel application (or if you already have it running then select New from the File menu in the MainBox.

Now select Open svx... from the File menu in the MainBox and browse to the location of your Survex data file. (We will be using ExampleCave.svx). You do not need to have put this file in any special location, as Tunnel will create a copy of all the data in it. Once you have opened your svx file you should be able to view the cave centreline by selecting Whole Cave from the View menu.

We now need to set our project directory where Tunnel will save all the data files for this project. Select Set XMLDIR from the File menu. Navigate to the location where you want to save your project data for this cave. It is recommended to choose an empty directory rather than the location of your existing svx file, as Tunnel may overwrite your original data file if you choose the same location for your project. You can create new directories from this dialog too.

Once you have set your XML directory, you can select Save XMLDIR from the File menu. This will create all the data files for your new project in the location you specified in the previous step. The MainBox window should contain a data tree in the left pane, with a Root folder containing document icons for the cave symbols (gsymbols) and your cave data (ExampleCave if you are using the example data). Select the ExampleCave document icon in the tree, and you should see the files located in this project directory in the right pane. They should be highlighted in green to show that they have been saved and no changes have been made since the last save.

It is a good idea to exit Tunnel at this point, and restart it to check that your project is set up and working properly before starting the drawing. When you have restarted Tunnel, select Open XML dir... from the File menu and browse to the location of your project directory. You should be able to select the ExampleCave document icon as before and see the file list highlighted in green as before.

Tip: Once I have a project set up, I create a copy of the r.bat file which I use to start Tunnel, and add the path to the project folder to it. Save this file as r_examplecave.bat and you can now start Tunnel with your project opened automatically each time you come to work on it.

Creating A Sketch

Now we are ready to start drawing our survey plan view in Tunnel. Select the Example Cave icon in the left pane of the MainBox window so that the MainBox looks like the screenshot above. Next select New Empty Sketch from the Tunnel menu. This will open the sketching window, showing an empty sketch. This should look something like this:

Note that the MainBox window is now showing an additional file, highlighted in red. This is the sketch file, which will contain all the data for your drawing. It is shown in red at the moment because there are unsaved changes. You can save the changes to your sketch at any time by selecting Save XMLDIR from the File menu in the MainBox.

We will be working in the Sketch window for the rest of this tutorial example. Just remember to save your changes in the MainBox before you exit Tunnel.

You can resize the sketch window to make it as large as your screen. This will make it easier to work for you, but I will be keeping the sketch window small for this example so that the screen shots are not too large for the web pages.

Importing the centreline

Select Import Centreline from the Import menu in the sketch window. This will import your cave survey centreline data into the sketch. You should see the centreline displayed as a set of red paths with blue nodes at the path ends (corresponding to each survey station).

Loading the background sketch

Next we need to import our scale drawing of the cave corresponding to this centreline data. Look at the bottom half of the left pane of the sketch window, and you will see a set of tabs. The subsets tab is currently selected in our previous screenshot. Select the background tab, and you will see a set of buttons and tick boxes relating to the drawing background.

Click the Add Image button in this pane, and browse to the location of your scanned survey plan sketch. Select the image file which contains your scanned sketch and select Open. You should now see your image displayed under the centreline data in the sketch window.

Note that the scanned drawing is not correctly aligned to the cave centreline data. We need to align it by using paths. First pick a point on the background drawing that corresponds to one of the points on the centreline. Draw a straight 2 node path which starts at this point on the background drawing and ends at the position of the actual centreline node which the point should be aligned with. It is best to zoom in on the sketch to do this more accurately. (If you do not know how to zoom and pan the sketch, or draw paths, then you should have read the earlier sections of this tutorial as suggested at the start of this example!).

Remember to hold down the CTRL key rather than the SHIFT key to end a path at an existing node (in this case the centreline node).

Now with this path still selected, click the Shift Ground button in the left pane to move the background drawing so that the two points at the ends of the path are aligned one on top of the other.

Now zoom out so you can see the whole sketch. You will see that we have aligned the drawing with the centreline at one point. Now we need to scale and rotate the drawing so that it is completely aligned with the centreline data. This is done by drawing a 3 node path. The first node should be the point where the drawing and centreline are already aligned. The second node should be a different point on the background drawing which needs to be aligned to another survey station. The final node should be the survey station on the centreline which needs to be aligned to the second point.

Note: I have rotated the sketch slightly in this screenshot to show more clearly where the middle node is on the 3 node path.

Click the Shift Ground button again with this 3 node path selected, and the background drawing should be properly aligned with the centreline data.