On AutoCAD, Layers are like levels or sheets, of which we can assign certain parts of a drawing.
Through the appropriate command window, we can create at will and can set a name, a base color, and a kind of linetype.
The base Linetype and color however it isn't binding, in fact within the same layer you can draw with any color or line available, using the function seen previously.
Let's see the “layer toolbar”:
Clicking the first button on the left of the toolbar: will open the window "layer manager", here below:
On the "Layer Manager", we see at present, only the layer "0".
Above are the fourkeys ;except the second, they mean:
-New-layer (to create new layer)
-Delete layer [ note: you can not delete layers that are not empty]
-Set current (set as the current layer)
We can create multiple layers, but will draw always on one at a time, the current layer.
If we click “new layer”, will create a new layer called “Layer1”, which will appear in the window. Right now if necessary, we can just rename it at will.
The following image, I created two new layers, the first, layer1 I left as the default, the second I renamed as “Pavimento”, I assigned the color red and I changed the line type in HIDDEN, as base settings.
To rename a layer, we have to select it in the layer manager and press the
“F2” key on your keyboard.
The layer name will edit it and we can rename it at will.
To close the window of the layers we have to click the X in the top left of the window.
The current layer is stayed 0, as we see written in the small window of the “layer toolbar”
This means that the lines we draw will be part of this layer.
Clicking on the window of the “layers toolbar” opens a drop-down list where we see the layers in the drawing, then ‘0’, ‘layer1’ and ‘Pavimento’.
Selecting one of the layers present, such as ‘Pavimento’, will set it as current layer, from then on the lines or objects that we are going to draw belong to this layer, and hence will have the characteristics we have set, red color and line type HIDDEN.
This at least, if we leave the setting “BYLAYER” for the color and linetype on the “properties toolbar”; if we assign a different color or line type, different from those set for the layer, these will take precedence and will be used to draw.
The hidden line display, depends on the variable LTSCALE.
Attention now: Doing the same operation, by selecting a layer in the drop-down window, but after select one or more objects in the drawing, we will change the layer of these objects, but in this case, when press Esc to deselect it, we see that the current layer remains ‘0’.
Then we assigned the layer “Pavimento” to selected objects, but we continue to draw in the layer 0.
In summary, we can create different layers and assign color name and linetype.
We can set object colors as desired, or leave them as layer setting "BYLAYER".
We can assign to objects different linetype, or leave them as layer setting "BYLAYER".
As you may have noticed, both on the layer drop-down menu and in the layer-manager window, there are other symbols for each layer: a light bulb, a kind of sun, and a padlock.
Are the controls, ON / OFF, FREEZE, LOCK.Both from the drop-down list of layers and from the layer-manager window, can act on these functions.
The first, ON / OFF, allows you to set visible or not, the various layers present , then if you open the drop-down menu and you click the “bulb” of layer “Pavimento” you set it off, so objects that are part of the design of this layer will disappear.
Repeating the operation reactivate the layer, the design reappears on the screen.
The FREEZE function is equivalent to say that first described, at least as regards this course.
You have to keep in mind that a layer set to “off” can remain as the current layer, then we can draw with it.
If we draw a line using a layer off, it will not appear on the screen, since the layer is disabled, but will be drawn and we will turn it visible, resetting the layer to ON.
Otherwise, a layer set to off with the FREEZE function, can not be used as the current layer, thus preventing you can continue drawing in it.
The LOCK function instead, when enabled, will lock the layer concerned, which remain visible on the screen, but should prevent edit or delete the parts that are already draw on this layer.
Also in this case, It will be maintain the current layer “locked”, but we can continue to draw objects inside which, however, once created it will be immediately blocked and no longer editable until we turn off the ‘lock’.
In practice the layer is used to subdividing drawings to some parts, such as plant design of a room can be divided into several layers of walls, floors, furniture, false ceiling...; and if necessary, turning off or locking, the layer on which we must not work or that we do not want to see.
Although you can create a vast amount of layers. ... And many do so, (you will realize if you happen to work on drawings made by others), you should not overdo it and kept to the minimum necessary, to maintain order in the design as much as possible and not lose control of what you're doing.
It will be very easy indeed if not, end up with parts of the design scattered to many layers where they should not be, and have to wasting time to fix it up.
You will see that this happens even working with only two layers, if you are not careful.A good technical design, could also be on a single layer, limiting itself to use different colors for different kinds of objects, such as walls, floors, furniture, etc.