While playing with TouchDraw the other day I realized that the unlimited page size would help us get rid of another piece of complexity in our field drawings. Our drawings are usually done at 1:20 scale since this is the largest scale that will fit on an A3 sized sheet of paper. The standard method of drawing is to have something static, like the sides of the trench or a baseline, and measure an object from those static lines. Measure from two sides, find out where they collide, and you have a point that you place on your paper. Measure enough of those points and you can connect them with a freehand line that represents your object.

The problem is transferring the ruler measurement to the paper. You could use an architect’s scale to handle the math; or after enough time, you can do the math in your head. Whichever you do, you have to convert the measurements on the ruler to the measurements on the grid paper. Last year we worked in pixels, not centimeters, so things were slightly odd, but this year we can use the unlimited paper size and units capabilities of TouchDraw to help us even further.

The test drawing below is a 1:1 drawing of a trench with an SU in TouchDraw.

There is still a little bit of math to do. The numbers on the rulers are centimeters, not meters. But almost everything we measure ends up in cm.

Drawing at this scale is a little tricky. The lines, for instance, are anywhere between 15 and 30 (I assume pixels) wide. The text is 300 (again, I don’t know the unit, but I assume pixels or points). But dropping the necessity for scaling makes converting the ruler measurements so much easier.

Note the blue lines above. Those are my ruler lines. If I make the strictly horizontal or vertical (by using the function lock, the little fx on the lower left that acts as a shift-constraint), I can type the length of the line in the overlay (the gray HUD on the right). Where the two lines join, I can make my feature. When I don’t need the lines, I just delete them.

I was able to add the elevation symbol and the SU name to the library easily enough so they can be used over and over. The elevation symbols are a group of three lines and a text box, but if I lay one on the page and double tap it, I can edit the number on top very easily.

I worry some about the line thickness. This is something that you don’t get in CAD environments, but you have to deal with in straight vector or paper drawings. As you can see from the second screenshot above, the lines are roughly .5cm thick. This is roughly the equivalent as the thickness of a line on pencil paper, which is why archaeologists tend to aim for centimeter accuracy. But that might not always be desired. If you take a look at the top image again you can see that we can remove yet another leftover from the old pencil drawings and that is our dependency on pencil lines altogether. The SU shape has no line, just a semi-opaque shape.

The original TouchDraw document can be downloaded from here for experiments.

We leave for the field in a couple of weeks. In the meantime I am gathering some comments from the field supervisors and getting ready to make and test the last additions to the database before we go.

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