Author Topic: Furloughed Tutorial - Winnats Elevation  (Read 477 times)

Online alastairgott

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Furloughed Tutorial - Winnats Elevation
« on: March 31, 2020, 11:34:48 am »

With a lack of other things to do, the lectures continue (or tutorials), I think they're called lectures if everyone's yawning at the back  :sleeping: and tutorials if they get out a big stick and make you do work.


 either way, not arsed about anyone hopping in on this thread and asking questions or posting up problems from other caves, might make it a little livelier.


So this time, we're leaving the plan alone, as I've not received anyone's work on Fox chamber yet...


And we're going to concentrate on the elevation, one which will be familiar to those who read COPD and those that drew the original. I'm going to show how we can manipulate the drawing, which could prove useful in some caves where you for instance find a bypass or other passage which completely wrecks your elevation drawing.


I'm not sure if I explained it last time, but it's important we define the scrap scale and the projection, this is done in the tab on the side marked scraps.


Projection
Pretty self explanatory, each scrap needs to be defined as either plan or extended, (ignore the "elevation" or none, as these are seldom used, elevation is for a cross section at a particular angle- useful but not right now :) )


Scrap scale
In this case, Wardy has given us some lovely scales on the side of his drawing, so I've picked the top scale from 0 to 35. I moved the ends of the red arrow across to these points. and then set the "real scale point" box to be -35 with the rest of them being 0.


this means that in high school speak we've given it x & y for zero,zero (at 1140,-65) and x & y for -35,0 (at 1979, -65).
ie no change in y but changes in the x value.


it will only show the scale bar when we have the start of the scrap highlighted.


Plotting survey points
now we need to highlight endscrap to start adding things to this drawing. We need to ensure these are between the start of the scrap and the line that says endscrap.


Remember that game that teachers made you play, "Simon Says", this is a lot like that, if the things that your adding into the drawing are not between these two lines, then the software will ignore you.


It's really useful to have the survex model open at the same time when plotting the survey points.


So to add in a survey point, select the point tool (survey station is default), click where you want the survey station to be and in the points window on the side, type into the options command box -name fc5


the -name tells it to look for a survey point in your .th (data file), so when we look in ours, we can see fc5 is the big boulder in fox chamber, that description is good enough for me and matches with the survex model.


So we can do a simple elevation by drawing round the walls and plotting some of the points, but not all. for speed, I will do this.


Errors
Sometimes you will get an error when you run the file, the best way to combat this is to run the file very regularly, so you can understand what it doesn't like.
 I just got an error which tells me that when I typed fc5 (for that point I showed you how to place), this did not match the survey data which uses capital letters, so a quick amendment of that point to FC5 will sort the error and allow it to run.


Your first elevation :lol:
So you're first elevation will turn out like the attachment below, it's a pretty picture but we've got water being held in a nearly upside-down sump. and all manner of weird squiggly lines.


I will teach you how to get this under some control...

Online alastairgott

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Re: Furloughed Tutorial - Winnats Elevation
« Reply #1 on: March 31, 2020, 12:42:06 pm »
So we've got something vertical going on, which is great!

However we want to control that verticality, and we do that in our data file.

again get your survex model up, alongside your drawing. You'll be making amendments to your data file.

But there is one thing I want to try first, and that's to change that scrap scale from being -35 to being just 35, ok, so it's not budging.



What is an extended elevation?
There's one classic example of an extended elevation that I know of, and that's P8. specifically of the areas beyond sump 1. In plan view, you can see loops of passage where the stream has followed the will of the rock.


However in the extended elevation, these have been straightened out so all you see is the profile of the passage as though your walking down it, it's this effect that we're looking for in our survey.


not a view from the side at a specific angle

Online alastairgott

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Re: Furloughed Tutorial - Winnats Elevation
« Reply #2 on: March 31, 2020, 01:02:52 pm »
The Extend Function.



At the moment, the survey is swinging about at it's own will, so we'll start at the bottom and work our way up.


The first thing you will notice is that the points from PW53 to PW57 are all going in a direction to the left.


so we can add in a line to our data file that says this is what we're expecting.


extend left PW53
(this function tells the software that all points after point 53 should be going to the left).


this is great, but we know that PW57 is directly above PW58 in our diagram, sometimes this could be a rift where you need to get an angle on the shot to get it down the rift, but in the diagram we draw these above each other, so it's important we tell it that we need a vertical shot on this one.


extend vertical PW57 PW58
(software now knows that this should be placed in a vertical line).


So lets try those extends in our file. We can see that it's starting to take some shape at the bottom there.




Online alastairgott

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Re: Furloughed Tutorial - Winnats Elevation
« Reply #3 on: March 31, 2020, 01:19:08 pm »

Adding in a few more:
extend left PW47
extend right PW48
extend vertical PW49 PW50
extend left PW50
extend vertical PW52 PW53
extend left PW53
extend vertical PW57 PW58


gets it into some more shape, you get the picture I guess.


I'll continue doing the rest and then show you how to completely alter the picture from the original.

Online alastairgott

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Re: Furloughed Tutorial - Winnats Elevation
« Reply #4 on: March 31, 2020, 02:11:10 pm »
So now with a full list of instructions we can replicate the section of the cave as seen in COPD

extend vertical FC5
extend vertical PW8
extend right PW11
extend vertical PW14
extend left PW18
extend vertical PW28
extend vertical PW33 PW34
extend left PW34
extend left PW35
extend vertical PW37 PW39
extend right PW39 PW40
extend vertical PW40
extend left PW41
extend vertical PW44 PW47
extend vertical PW47 PW48
extend right PW48
extend vertical PW49 PW50
extend left PW50
extend vertical PW52 PW53
extend left PW53
extend vertical PW57 PW58

We can now play around and break it a little bit by flipping specific sections, and then rejoining them.

Online alastairgott

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Re: Furloughed Tutorial - Winnats Elevation
« Reply #5 on: March 31, 2020, 08:43:15 pm »
At this point I need to go back to the subject of Maps and Scraps. If you remember from before, the Scrap is the smallest drawing object we can make, and we use them for such things as overlapping passages. (because the software only sees what you give it, ie an overlapping passage is a solid rock wall).

The smallest drawing units (scraps) are also useful if you want to connect two bits of cave together. Say you had an aven coming down into a known passage underneath, you descend the aven and can get a better survey of it that way. therefore you may wish to simply throw away the small section of passage at the bottom of the aven, however you've drawn it all in one lump.

Therefore we need something called a map, which controls precisely what we see when we process the data.

In the case of Winnats I've got the "up" pitches, so perhaps I've got a better survey showing them linked in and I simply want to chop out the walls above the "down" pitches.

I don't know if there's a textbook method for this, but I'm going to give you mine.

I would go into my drawing file, and start to break the lines up. Firstly by inserting a point where you want to break the line, and then by using the split line tool (picture below).


After we've done this, we can then create a new scrap for the bits we don't want, I tend to call these scraps REDUND (for redundant). so the first thing you need to do is select the end of the file, then hit insert scrap, 3rd step rename the scrap, then 4th step change the projection of the scrap, then you'll need to select on of the objects (walls) that you want to move, then your 5th step is to select where you want it moving to
 Finally you can hit the move to button, you'll get fairly used to this when you've done it a few times.


There are other ways of doing this, but they rely on you being very organised with where you place things in the object box, I don't usually make time to be organised like that. I just get on with it. but so you know, anything you place in the file comes up as a line in the file, you can look at the file as a wordpad document, therefore if you know you need to make a mass change and everythings in good order, you can just copy and paste the lines and create the scrap with text straight into the file [but let's not get carried away!].


Anyway Maps
Fairly important this, for all therionising!


As I said before we want to throw away that redundant bit, so we need a way to not select it for drawing, we'll do that by creating a map command in our data file, it looks like this:


map Winns_underfox_Ee -projection extended
OldelevationwinSE1
endmap


So much like we talked about the software only doing things we tell it to (simon says), again we've got another situation where this is true, we've separated out the REDUND and now only include OldelevationwinSE1 in a map command.


We also name these map commands too, so this one I've called Winns_underfox_Ee
This is so I can find it when we're running it at the full cave (probably cover this later unless I get bored).


and we also give it a projection, as you can run both maps for plans and maps for elevations at the same time in the same data file.


That's it, we can run the file.


By moving these items, we've created a hole in our final file, which we could fill when we run the survey at a higher (full cave) level.

Online alastairgott

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Re: Furloughed Tutorial - Winnats Elevation
« Reply #6 on: March 31, 2020, 09:25:44 pm »
Now using the same logic of splitting lines and creating a new scrap, we can flip the pitches below Maggie's Britain.

so we'll create a new scrap called OldelevationwinSE2

and then enter this into our map in the data file

map Winns_underfox_Ee -projection extended
OldelevationwinSE1
OldelevationwinSE2
endmap



then we can use an option called
-flip horizontal


Once we've done all that, we'll then need to go back into the data file and change all of the extends in the file to ensure it generates in the correct direction. the only commands we have below Maggies Britain are:
extend left PW53
extend vertical PW57 PW58


we can ignore the extend vertical
but the extend left needs to be changed to:
extend right PW53


the Hash symbol is a comment, so a lot of the time, I will leave the original command in and hash it out and then put the command in that I want below


ie:
#extend left PW53 #Commented out AG 31.03.20 for flip Horizontal
extend right PW53 #AG added 31.03.20 to flip Horizontal.


I just find it's good practice.


run the file...
 (don't worry about the line ends, these can be nudged back into shape).

Online alastairgott

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Re: Furloughed Tutorial - Winnats Elevation
« Reply #7 on: March 31, 2020, 10:52:47 pm »
Final post for today, promise. moderately finished Elevation (not perfect, but gives you a taste).

 

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