Nine Types of Project Drawings can be overlaid in one composite model:
Each project may require several different drawing types, such as electrical or plumbing plans, that make up the drawing set. MYCADLAYERS provides a method of Overlay Drafting that allows up to nine drawing types to be integrated in the one composite model.
In an architectural environment Drawing Types may range from: drawings for client approval, planning and building regulation approvals, sales and marketing, title delineation, licensing and fire safety approval, to construction and as-builts and for many other reasons.
Traditional drafting, including much of that done by CAD, results in repeated drafting of the same objects in each of the separate drawing types. Overlay drafting (using separate sheets of clear film) was a partially successful means of using the same single set of information in several different final drawings but AutoCAD with its unlimited layer system provides a much more efficient method of doing this. With careful planning and control of layers no object needs to be drawn more than once. The result is time saving in production and editing, greater reliability in the accuracy of the information and smaller files..
The MYCADLAYERS' method of layer naming and control allows a single CAD model to contain all the data for an entire project while providing a simple mechanism for separately viewing and printing each of the required drawing types.
Each drawing type is assigned one of a special set of nine numbers. Starting with 1 and doubling each step these numbers are: 1, 2, 4, 8, 16, 32, 64, 128 and 256. Used in layer names these codes become 001, 002, 004, 008, 016, 032, 064 128 and 256. Although there are many possible combinations of these numbers every combination will give a unique sum. Layer names will include one of these nine codes or the sum of several or all of them. If one of the nine codes appears in a layer name it indicates that the objects with that layer name will appear exclusively in the relevant drawing type. If the number is the sum of a combination of two or more codes then those objects will appear in each of the drawing types indicated by the component codes; for example a layer name with a drawing-type code of 511 indicates that that particular data applies to all nine drawing types in the project. Because every different combination of codes produces a unique number data can be excluded from the drawing types to which the data does not apply simply by insuring that the relevant code is not included in the composite code number.
This code concept may at first appear complex but actually proves to be quite simple in use. The MYCADLAYERS layer dialogue box aids the operation; by clicking on the required drawing types layers automatically acquire the correct code sum. Complimentary Autolisp functions within MYCADLAYERS automatically decode the code-sum and produce the correct layer display in both modelspace and paperspace. Experience has shown that operators rapidly become familiar the process and can produce the required codes even when entering at the keyboard in preference to using the dialogue-box.
How to create a drawing-type code:
- A drawing type number that is made up of a single code indicates that the layer is unique to the relevant drawing type.
- A drawing type number that is the sum of more than one code indicates that the layer appears in all drawing types that are included in the composite drawing type number.
- To add a layer to another drawing type; add the relevant code to the drawing type number.
- To remove a layer from a particular drawing type; deduct the relevant code from the drawing type number.
- All of these operations are automated using MYCADLAYERS.
- Drawing-types can vary from project to project. Their names and order are nominated by the drafter, usually to match the order of drawings in the drawing schedule.
Pre-defined or Customized drawing-type schemes:
MYCADLAYERS’ dialogue box includes a choice of several predefined schemes of drawing-types as well as a facility to create user custom schemes.
Although the standard MYCADLAYERS layer dialogue-box offers a convenient set of drawing types for building construction, these are easily customized to suit other applications. A separate dialogue box is provided for changing the drawing types for individual projects. Users can easily customize the list of drawing types project by project.
As an aid when entering layer names at the keyboard each drawing-type is assigned a single character mnemonic code for use with MYCADLAYERS viewing command.
Example Project drawing-type scheme:
Drawing-type Shortcut Code
General Arrangement G 001
Demolition D 002
Set-out (dimensions etc.) S 004
Marketing / tenancy / areas M 008
Ceiling C 032
Electrical E 064
Plumbing and drainage P 128
Fire zones F 256
Create custom project drawing-type scheme:
For each object in your CAD model, decide upon the drawing types in which it is to appear, then add together the numbers assigned to each of these drawing types. This will give a composite number that encodes the drawings in which each object is to appear and excludes those in which it is not to appear. Objects may appear in one only, more than one or all of the drawing types. An object, such as a wall, that appears in all drawing types will have the number 511 (the sum of all the code numbers 001 -256). This resultant number is used in the object's layer name and must always be padded with leading zeros to make up three digits e.g. 008. If one of these codes appears in a layer name it indicates that the objects with that layer name will appear exclusively in the relevant drawing type
Although the default MYCADLAYERS main layer dialogue-box offers a convenient set of drawing types for building construction, these are easily customized to suit other professions. A separate dialogue box is provided for changing the drawing types for individual projects. Users can easily customize the list of drawing types project by project.
Command LR, Layer Resolve, prompts for one of the nine drawing-type code numbers or its mnemonic code followed by prompts for Viewpoint and View ID. This will instruct MYCADLAYERS to display the layers relevant to the chosen Workzone.
Drawing types dialogue-box:
Allows selection or creation of alternative drawing-type sets for different project types.