First let's define what a LAYER is and what it is NOT.:
AutoCAD persists in describing Layers thus: "Layers are like transparent overlays on which you organize and group objects in a drawing." This has been and still is the greatest disservice that Autodesk could impose on AutoCAD users. The concept that a Layer is a surface or transparent film or even a collection of objects drawn on a transparent film is misleading.
Let's start again at the beginning. All objects in a drawing have various properties one of which is a LAYERNAME. This particular property could just as easily have been called Object FUNCTION, CLASS, FORMULA, etc. Yes; all a bit clumsy and none of them convey the full nature of a LAYER so let's stick with LAYERNAME. Note that I use "LAYERNAME" not "LAYER" because LAYER still hints at the transparent film concept whereas objects with the same LAYERNAME can exist in many different drawings and in three dimensions. The most important feature of a LAYERNAME is that it can convey many different implied properties.
A Layer naming standard is the cornerstone of any CAD system and is at the heart of efficient drawing production.
Benefits of a layer naming Standard:
- No time wasted thinking what to call a new layer
- No time wasted working out the function of an existing layer.
- No confusion over the order of or abbreviation of layer name fields.
- Drafters are interchangeable without confusion.
- Drawings are shareable without confusion.
- Layers with common characteristics can be managed using wild-cards.
- Editing time is reduced.
- Accuracy is improved.
Layer naming Standards:
Much effort has been put into a producing a Layer naming Standard. In Europe the outcome was ISO/DIS 13567, a generic system applicable to all professions. The result was somewhat complex as it tried to be all things to all people. Nevertheless the principles are very sound and will provide a basis for your own custom system. The US developed its own system based somewhat on ISO/DIS 13567. Neither of the two, or any other system that I know of, has provided a consistently workable standard capable of practical adoption.
Nevertheless systematic layer naming is the key to good data management. Any system is better than none but Layer naming continues to be one of the most tedious and time-consuming, yet most important, tasks in CAD.
Unless color and line-type are assigned BYOBJECT rather than BYLAYER each LAYER has at least the following properties.
In addition most layer name Standards use the LAYERNAME to imply a number of additional object properties.
MYCADLAYERS, like many other layer naming standards, extends the properties of objects by embodying properties in the Layer-NAME itself. Such properties could be Object-type, Job-status, Drawing-type, View-point and Location of the objects in a drawing set. For example: "BRI 3 7 X 511 P 02" (expanded for readability) that means: "BRIck color3(green) line-type dashed(7) Xisting Plan-view level 02". This defines the building element's drawn graphics, its project status, drawing type and location in a drawing set. Looking a little closer it can be seen that the first five characters define drawn nature of the object and the last seven where they belong in a drawing set. If a drawing has a simple single purpose there is no need to include the latter seven characters. A five character layer name may be sufficient and in fact for many simple drawings any more is a waste of time. So much for complex national layer-naming standards. MYCADLAYERS provides an automated system for generating and managing layernames and their properties and permits the use of either five or twelve character layernames or may simply be turned OFF when not needed.
MYCADLAYERS makes the following AutoCAD commands virtually redundant:
- VPLAYER Newfrz and Vpvisdflt options
Layer name length:
MYCADLAYERS provides for two different layer name lengths of either five or twelve characters, or may be turned OFF, depending upon the drawing requirements; twelve for drawings with defined Workzones and five for simple one-level one-concept drawings or OFF if a naming standard is not required.
When MYCADLAYERS control is set to 5 or 12 characters new layer names created by MYCADLAYERS adopt the correct length and format according to the current setting of layer-name length. When layer control is OFF, uncontrolled entry of layer names is permitted. A one-off uncontrolled entry may also be achieved without re-setting the current-layer-name length by pressing ` (back quote) prior to entering the layer name. This has the effect of turning layer-name length to OFF for the current entry only. (similar to invoking a generic Autocad command using a MYCADKEYS alias).
By default MYCADLAYERS starts up with layername control OFF. The user toggles between: OFF, 5chr, or 12chr by entering the alias $7<enter> or pressing Function Key 7 repeatedly until the required number of layers is set.
Saving MYCADLAYERS layer settings:
Layername length and associated WORKZONE settings are saved with the drawing from session to session and may be easily changed at any time. The results are displayed in AutoCAD’s status line.
MYCADLAYERS Dialog box:
While learning a 12chr MYCADLAYERS dialog box is available that displays each layer field as a scroll-able list of optional pre-set user choices. Alternatively the operator may type a response into the “other” box. The dialog box can save time by using the current layer name as a template in which fields may be optionally changed to create the desired new layer name. The resulting layer name then becomes the current layer. New layers are automatically created with the correct color and line-type.
Examples illustrated are Architectural but are fully customizable.
Layer names are made up of seven fields: Object, Pen, Line-type, Status, Drawing-type, Viewpoint and View ID. All but the Drawing-type are scrollable columns that can contain as many options as desired. All options are editable to suit the individual projects and disciplines. Drawing-type has nine check-boxes related to the bit-codes 001 to 256. All or as many of these as is relevant may be checked indicating what drawing-types a particular layer appears in. The drawing-types themselves are also editable using a separate dialogue box "Change drawing types" that allows the creation of alternative drawing-type schemes.
If an acceptable code is not found in any column the user may create a new code using the "other" option at the bottom of the column.
The "Make Layer" note at the bottom left by default shows the current layer. This changes progressively as options are selected to indicate the new layer name. Typically only one or two fields may need to be changed thus further reducing the effort to create new layers. When finished press "OK" and the new layer complete with correct color and line-type will be created and made current.
The drawing-type names to the right of the check-boxes show capitalized letters that may be used as mnemonic substitutes for entering the full three digit number when using keyboard entry instead of the dialogue box.
Keyboard v dialog box:
Designed mainly for new users but like all other AutoCAD commands experienced users will find it quicker to use the keyboard once they are familiar with MYCADLAYERS naming conventions. The keyboard is as always a faster and more complete interface and prompts the user through each relevant data field, accepting only appropriate entries. All MYCADLAYERS commands that use Layer names accept the keyboard method.
Drawing-types relevant to project:
Although for many projects the preferred drawing types and code assignments will be the same, on occasions it may be necessary to use a different drawing-type scheme. This is provided for in the system. It is possible to have a different set of drawing types for every project. The selected Drawing Types Set is saved with the drawing and automatically appears in the layer dialog box in subsequent CAD sessions. To change the scheme select “Change drawing types” in the bottom right corner of the Layer dialogue box.
Examples of OBJECT codes might be:
Construction: --- all ALUminium BEAm BLOckwork BRIckwork CABinetwork CEIling CERamic tiles COLumn CONcrete DOOr DP_ DownPipe EARthwork EQUipment FENce FINish FiXIngs (screw) FLAshing FIXture (basin) FLOor (surface) FOOting FURniture GLAzing GRAphic/sign GRIlle HANdrail HARdware INSulation JOInery KERb MEMbrane METalwork PAInt PARtition PAVing PIPe PLAster RENder RESilient fin ROAd ROOf SEAlant SLAb STAirs STEel STUd walls TILes THReshold TRUss VENt WALl WINdow WIRe WOOd
Discipline: BUIder CIVil COMunictns ELElectrical ESCalator EXTernal GRAphics HYDraulics INTerior LANdscape LIFt MEChanical STRuctural SURveyor
Reference: FRAme GRId LABel LEVel LEGend SCHedule TITle VPOrt
Examples of PEN codes might be:
Pens printed in BLACK - standard line thickness:
In order of Pen-number, Line-thickness, Full Color Dark Color Light Color
1 0.18 red A clr 12 G clr 14
2 0.25 yellow B clr 52 H clr 54
3 0.35 green C clr 92 I clr 94
4 0.5 cyan D 1clr 32 J 134
5 0.7 blue E clr 172 K clr 174
6 1.0 magenta F clr 212 L clr 214
7 0.18 white temporary highlight.
8 0.18 light grey hatch
9 0.18 dark grey grids
Pens printed in COLOR - line thickness custom
In order of Pen-number, Color-number, Plot color
M 10 red, N 30 org, O 50 yel, P 70 lime, Q 90 grn, R 110 aqua, S 130 cyan, T 150 lt-blu, U 170 blu, W 210 mag, V 190 prpl , W 210 mag, X 230 crim, Y 35 brown, Z 11 peach
! clr 250 15%, $ clr 251 30%, % clr 252 45%, ^ clr 253 60%, & clr 254 75%
Examples of LINETYPE might be:
- continuous 1 border 2 center 3 dashdot 4 dashed 5 divide 6 dot 7 hidden 8 phantom Special A Attrib B Block D Dimension F Fill H Hatch L Leader T Text M mview Xref Y sYmbol S Sewe
Examples of STATUS or STAGE might be:
Status: - proposed B asBuilt D Demolish E Existing F Future M Msured N New O Obsolete P Prelim R Relocate S Set-out T Temp U re-Used
Stage: - current 1 2 3 4 5 6 7 8 9 0