Chapter 2: Referencing, Layers and Drawing

Include an excavation drawing

If we want to redraw something, we first need a drawing that we can reference to. Excavations produce a lot of drawings during a season and many of them still work analogue, that means with pen and paper. In order to digitise the drawing, we need a good scan first, that then has to be rectified in order to be used in our digitisation. Fortunately, this has already been done for you and you can download a JPG file that will serve as our reference here: Trench Drawing.

To use the drawing in our ACAD file, we will first create a new Layer. So first open up the Layer Properties (**Layer-Eigenschaften**) from the menu on top. We can see, that we have our system-layer 0 and our layer Excavation Grid. We will now create a new layer with the New Layer (**Neuer Layer**) button and name it Excavation Plan. Make the layer active by double-clicking it, leave or change the colour to white and then close the Layer Properties (**Layer-Eigenschaften**).

To link an image to our drawing, we will select the tab Insert (**EinfΓΌgen**) right on top to change the menu and then the button Assign (**Zuordnen**). We search for our drawing that ideally should be saved in the same folder as our drawing. In the new window, we should make sure that the Path Type (**Pfadtyp**) is changed to Relative Path (**Relativer Pfad**), as this refers to the image file relative to the position of our ACAD drawing. If we put both, the ACAD file as well as the image file, in the same folder, we can put the whole folder on an USB drive and take it somewhere else. So hit OK and the window disappears.

ACAD now wants us to select a starting point. Chose something inside the excavation trench limits, but don't put on top of the crosses. If you click once you'll see see a rectangle that you can scale. Make the rectangle fit roughly inside the green crosses of out excavation trench and click again. You should now see an image file inside of your drawing space. If you take a closer look now on the image, you should see four very faint crosses in each corner of the drawing. These crosses represent the 10x10m trench on the drawing itself. We now have to match this to our excavation trench, so the drawing is connected to ACAD in the correct scale.

We start by positioning one of the faint crosses under one of our own green crosses. To do so, we want to move the lower left cross of the drawing under our lower left green cross of the excavation trench. First, we select our drawing by clicking on the border of it. The menu on top changes automatically, so we change it back by clicking on the Start tab and select the Move (**Verschieben**) tool. We now have to select the point on the image file, that we want to move and we need to select as precise as it is possible the centre of the lower left cross (on the image file).

Make sure, that your Snapping is turned off, by checking the rectangle icon in the lower right menu is grey and not blue. If you want to toggle Snapping you simply hit the F3 button. You can zoom in and click once at the centre of the lower left cross on the image file. If you zoom out, you'll see that you can now move the image around. What we want to do is to position this exactly under the lower left cross of our excavation trench. We will now turn Snapping on (F3) and click in the centre of our green lower left cross. We only have the problem now, that the drawing is above the green crosses, so we need to change the order of things in our drawing. Select the image file, right-click somewhere in the drawing space and select Zeichnungsreihenfolge from the menu. In that menu choose Lowest (**Ganz unten**). Now the image file is under the green crosses and as you can see, the lower left cross of the image file corresponds to the lower left cross of our excavation trench. We now have to scale the image file in a way, that all the other three crosses are also corresponding to our green crosses in the corners.

So first, we will again select the image file and in the top menu change the tab back to Start. Now we select the Scale (**Skalieren**) tool. We need now to tell ACAD from which point we want to scale and we will select our zero point, that we just correlated with the image file. So with Snapping turned on, we click once into the centre of our lower left green cross. As we do not want to scale the image by hand, we want to select another scaling mode. As you can see in the Command Line at the bottom, there is a decision to be made. What we want is Reference (**Bezug**) and can choose that either by clicking on it in the Command Line or hitting the blue highlighted letter and hit enter.

Now ACAD wants to have a reference length of what to scale. Basically ACAD asks us what part of our image file we want to scale. For this we want to choose the length between the lower left and the lower right corner of the image file. So we click first (with Snapping turned on, because we already positioned the lower left corner under our green cross) in the centre of the lower left corner and then (Snapping now turned off, because we don't want ACAD to jump to another point) in the centre of the lower right corner (of our image file). Also: press and hold the SHIFT button, as this way the line between the two points stays straight.

You'll see now, that you are able again to scale the image file as you want. But we have a reference point we want to stretch that file into: the lower right green cross of our excavation trench. So now you turn on Snapping and click into the centre of the lower right corner of our green excavation trench et voilΓ , the image file is scaled correctly! You can check all four corners, but if you have done everything correctly, the image file should sit scaled and neatly under our green excavation grid, that we already have scaled in the previous lesson. The only thing I want you to change right now is, that we do want to see the original drawing in our Drawing Space, but not in our Layouts. If you have a look in our two Layouts, you'll see that the original drawing is also present. So let's change that.

So first we change to our first layout called Layout1_50 and double-click inside the frame to make it active, which will be indicated by the thick border. Don't move or scale anything! Open up the Layer Properties (**Layer-Eigenschaften**) and select the layer for our drawing called Excavation Drawing. If you go to the right, there is a column called AF Freeze (**AF Frieren**). You might need to widen the columns to see that. Click on the symbol in that column corresponding to your layer. It should change from a rectangle with a yellow star to a rectangle with a snowflake. You see immediately, that the original drawing is not visible anymore in our Layout. Double-click outside of the frame in the layout to make it not active and repeat the procedure for the other layout called Layout1_100.

Start drawing

Ok, let's start drawing! We open up the Layer Properties (**Layer-Eigenschaften**) and create a new layer called Excavation Outline. We want to change the colour of the layer to pink by clicking on the colour box in the list. We also activate the new layer and close the properties. To draw, we will use the Polyline tool (**Polylinie**) and make sure that snapping is turned off (F3). So back at the Drawing Space, we start at one corner an click along the outer line of our trench. We want to follow the line as closely as possible with only so much points needed. When you reach the border of the window, you can pan the view (Press Mouse Wheel) while still drawing. The goal here is, to go around the excavation trench one time with one polyline.

One important note: We of course want to think ahead! As we follow along the outer line of the excavation trench, we need to take care of intersections. So what does that mean? Every time the outer excavation trench line (the one we are currently digitizing) is crossing or touching another line (of a stone, a different soil colour or a mud-brick) we definitely create a point. The meaning of this is, that if we later redraw that stone (that is touching our excavation trench), we can connect the line of the stone with the point of the excavation line that we made earlier. This will help us tremendously later, when we want to fill the stones, soils and mud-bricks with colour. When you reach the end of the line, so basically the point where you started, make sure to turn Snapping on (F3) and click the last point on the first one, to completely close the circle. Turn Snapping off again (F3).

We will proceed with the mud-bricks. We again create a new layer that we call Mudbrick_Outline and give it a black colour. We can start with some easy mud-bricks that can be fully circled in one go. So you start at one point, go around the mud-brick and use Snapping to close the circle by clicking the last point exactly where the first point was. Press Space to exit the polyline tool and turn Snapping off again. More interesting though are not so easy mud-bricks, for example the one that are touching our excavation trench. Here, you should start at one of the open points of the excavation trench. Turn Snapping on, click on the extra intersection point we did earlier, turn snapping off and circle the mud-brick until you reach the second open point. Turn Snapping on, click on the intersection point of the excavation line and then exit the command by pressing Space and turn Snapping off again. You will not have fully closed the mud-brick, but because you have already drawn the excavation trench line, the mud-brick is nevertheless closed, as the mud-brick line (black) together with the excavation trench line (pink) are defining the whole mud-brick.

Make sure, to use at least three points on the corners of the mud-bricks to give them some details. Start redrawing all the mud-bricks until you are done. Practice, practice and practice. We still need to redraw all the other stuff in the drawing. The red pieces on the drawing are pottery and the white (or transparent) pieces are stones (sometimes with a K as a signifier, which of course you don't have to redraw). We call the layer for pottery Pottery_Outline and give it a dark red colour. The layer for stone is called Stones_Outline and give it a purple colour. Remember to activate the layer before redrawing and keep an eye on closing every object either by completing the circle or by connecting it to other lines and intersection points by Snapping.

When you have finished, we have to take care of the soil colours. If you have a closer look, some of the soil colours have a black outline and some of them don't. We will create a layer for the black outline as well as for the border between soils without a line. The black outline layer is called Terrain_Outline with a black colour and we can redraw them first. The layer for the border between soil colours without a black line is called Terrain_NoPrint and give it a bright blue colour. We do not want this line that we will create to be printed, therefore we search in the Layer Properties in the line of the layer we just created for a small printer symbol. If we click it, this line will not be printed, which is exactly what we want. We still need the line though to define the borders of these soils and we want to fill them later. We also do not want to show the line in our Layout, because the Layout should represent what we print. To deactivate the line for this, we change to our layout window, double-click inside the drawing to activate the thick border and then open up the Layer-Properties to click also the AF-Freeze (**AF-Frieren**) button. Deactivate the drawing by double-clicking outside of the thick border.

We now can redraw all the invisible borders of the drawing. Create a line in between different soil colours, always having an eye on fully circling each element in some way, so that we can fill it later. There are still some things to do. Two lines in the drawing is a black dash-dotted line (try to spot it). We need to create an extra layer for that called Terrain_Outline_DashDotted and give it a black colour. in the Layer-Properties we also change the Line Type option from Continous to ACAD_ISO10W100 by loading it into the list that appears. We should also use this line type for our excavation trench line (pink).

You can now proceed to Chapter 3: Hatching and Labelling.

This page was last edited on 2024-04-11 14:13

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This page was last edited on 2024-04-11 14:13

Sebastian Hageneuer
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