Layer Naming Q & A

Layer Naming - Questions and Answers:

How Many Layers should I use?   The principle objective of layering is to aid in drawing production, viewing and plotting; thus while more layers offer greater editing flexibility; do not unnecessarily add layers that will not significantly assist in the drawing or viewing process. The table of codes suggested by MYCADLAYERS is quite extensive but does not imply that all codes are relevant to every job. Neither is it an exclusive list; additional codes may be created as required. To assist those who come behind you use the accepted coding but if necessary add new codes for Objects not covered in the list. If codes are not easily comprehensible consider adding a legend on a non-plotting layer (LP-) where it will be clearly seen within the file.

How long should names be for simple drawings?   In simple circumstances detailed layer differentiation may not be required but always fill at least the first five character locations. A common example would be generic notes on layer “- - - 8 T “. It is not necessary to complete layer names beyond five characters if no further differentiation is required.

How long should names be for complex drawings?  If any additional field is required, fill all twelve character spaces. Use generic dashes if necessary, eg CON 3 4 – 001 P - - = (CONcrete, color 4, Dashed, status proposed, drawing type Builder, Plan, all levels. (spaces are added here for readability).

Why use such a complicated system?  MYCADLAYERS  looks very complex and is quite unnecessary for the way I work. or The method I use is fine for me and most people seem to be able to understand it; so why should I change?  

Most people agree that a standard of some sort is essential. Such a standard must satisfy the needs of every type of work. The trick is to devise a standard that is simple and easy to use for simple jobs while providing the level of sophistication required for more complex jobs. The proposed standard, with its supporting software provides for both ends of the spectrum

What is this point-and-pick feature?   MYCADLAYERS provides many point-and-pick Autolisp functions. Existing layers may be made current, turned off, frozen or locked at the click of a mouse button. Similarly objects can be changed from one layer to another by simple point and pick methods. The only time that layer names will have to be spelled out is during the creation of new layers. Even then the optional dialogue box can make this a simple point and pick process.

How am I going to remember all the fields and codes when I want to make a new layer?  Experience shows that only a few days are required to learn to manually enter MYCADLAYERS layer names. Alternatively MYCADLAYERS provides a dialogue box. Relevant codes are simply selected from each of the scrolling columns (fields). The current layer provides a default that may be edited so that in most cases only one or two picks are needed.

If I create an overlay drawing how do I display or print the particular View or Drawing type that I want?   In model space MYCADLAYERS command LR, (Layer Resolve) will ask what particular View, Drawing-type and View-ID you want and automatically resolve the layers to present the required display. A complimentary function is available in paper-space that will automatically scan view-ports, read their encoded layer names and resolve each view-port’s VPLAYER condition to correctly present the drawings they are required to display.

The object-type list is not detailed enough. In the dialogue box Oject list “BEAm” is provided, but what about steel beams or concrete beams?  This question potentially applies to all building Objects. Some layer naming systems provide an additional field for the nature or material of the Object so that BEAm STEel or BEAm CONcrete could be defined. An earlier version of MYCADLAYERS included an additional field as did an early draft of the ISO standard, but after trial it was discontinued since it did not usefully add to the objectives of layer naming and was frequently filled with dashes. The few occasions where differentiation is required the problem can be overcome by adaptation of the Object field such as BES for BEam Steel or BEC for BEam Concrete etc. Although the list of Object abbreviations provided is a recommended list, it may be adapted or extended as required.

The Pen widths listed do not match my current practice.  Common assent is required for any standard to work and any standard is better than none. The suggested standard is derived from the simple logic of ascending color numbers being related to increasing pen thickness. (also adopted by the ISO Standard) We recommend that color seven, (white), not be used for finalized building objects as this provides a powerful visual clue to operators keeping track of incomplete or unconfirmed data, construction lines and other temporary information and for checkers to mark-up the drawing. Smilalyr color 8 (gray) is useful for reference information such as notes, labels and dimensions.

Why include color number and line-type in the layer name?  Most Objects or materials will require several combinations of line-type and pen thickness within the same drawing. If the preferred standard of Color and Line-type BYLAYER is followed suitable layer names must be generated for each variation. Inclusion of line-type and pen thickness in the layer name is the easiest way to consistently achieve this and also provide powerful layer name automation capabilities. If they were not used then an alternative would be required. A typical operator is more likely to be able comply with office graphic standards than to be able to consistently remember an appropriate and unambiguous layer name based on descriptive information such as “brick, cavity face, hidden”, or “beam, centerline, over, minor” or “beam, note, 3.5”. In many cases, particularly in elevations, it is not necessary to distinguish layers beyond the Object code and its graphic representation. Object, Pen thickness, Line-type is a very simple way of doing this. Some tasks do not even require the object type to be encoded. In this case layers such as - - - 24 might be appropriate. Pen thickness and Line-type are simply an alternative language for describing concepts such as hidden beyond, cut in section, viewed in elevation and hidden behind, diagrammatic centre-line etc.

What is the purpose of the Object codes listed under the sub-heading Discipline?   Drawings often include reference data depicting the work of other disciplines, eg lift cars, mechanical equipment outlines etc. These objects are provided for reference and are usually presented in only the most rudimentary outline and do not require or allow the use of the more specific Object codes. Use of a discipline code such as MEC in the Object field clearly identifies areas of responsibility for design content.

Why encode text as belonging to specific object types?   There will be frequent occasions during editing that text relating to a specific subject needs to be highlighted to enable checking and editing. An example would be to ensure that wall finish notes have been provided for every wall in a building. Irrelevant and visually confusing data can be selectively switched off revealing only the specific text in question.

Why use such a complicated system?

The MYCADLAYERS system looks very complex and is quite unnecessary for the way I work.  The method I use is fine for me and most people seem to be able to understand it; so why should I change?

Most people agree that a standard of some sort is essential.  Such a standard must satisfy the needs of every type of work.  The trick is to devise a standard that is simple and easy to use for simple jobs while providing the level of sophistication required for more complex jobs. The proposed standard, with its supporting software provides for both ends of the spectrum

How do I use MYCADLAYERS and Workzones?

If I create an overlay drawing how do I display or print the particular View or Drawing type that I want?

In model space MYCADLAYERS command LR, (Layerr Resolve) will ask what particular View, Drawing-type and View-ID you want and automatically resolve the layers to present the required display.  A complimentary function is available in paper-space that will automatically scan view-ports, read their encoded layer names and resolve each view-port’s VPLAYER condition to correctly present the drawings they are required to display.