Lesson 5.11 – Batch Layer Creation Tool

🧱 Lesson 5.11 – Batch Layer Creation Tool with AutoLISP

Learn how to create multiple named layers with predefined color, linetype, and lineweight using AutoLISP.

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📚 What You’ll Learn

By the end of this lesson, you’ll be able to:

• Create layers automatically using AutoLISP
• Assign colors, linetypes, and lineweights to each layer
• Build a reusable layer creation tool for templates or standards
• Use the command function and tblsearch for managing layers

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🧠 Why It Matters

Layer management is essential in professional drafting. With AutoLISP, you can quickly set up drawing standards across files, saving time and ensuring consistency. Whether you’re standardizing for architectural, civil, or mechanical drawings, batch creation helps scale your workflow.

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🛠️ Tools You’ll Use

Function	Purpose
command	Executes AutoCAD commands like -layer
tblsearch	Checks if a layer already exists
strcase	Normalizes layer names for comparison
foreach	Loops through a list of layer definitions

🧭 Lesson Structure

1️⃣ Define the Layer Data

Use a list of layer definitions, each with:

• Name
• Color (ACI value)
• Linetype
• Lineweight

(setq myLayers
  '(("WALLS"     1 "Continuous" "0.50")
    ("DOORS"     3 "Dashed"     "0.25")
    ("TEXT"      7 "Continuous" "0.15")
    ("CENTER"    5 "Center"     "0.15")
    ("HATCH"     2 "Solid"      "0.00")))

2️⃣ Loop Through and Create Layers

Use tblsearch to avoid duplicates, then command to create layers:

(defun c:makelayers ( / name color ltype lweight layerDef )
  (foreach layerDef myLayers
    (setq name    (nth 0 layerDef))
    (setq color   (itoa (nth 1 layerDef)))
    (setq ltype   (nth 2 layerDef))
    (setq lweight (nth 3 layerDef))

    (if (not (tblsearch "LAYER" name))
      (progn
        (command "-layer" "M" name "C" color name "L" ltype name "LW" lweight name "")
        (prompt (strcat "\\nCreated layer: " name))
      )
    )
  )
  (prompt "\\nAll layers processed.")
  (princ)
)

🧠 Always load required linetypes before running this tool.

✅ Lesson Checklist

Task	Completed
Defined a list of layer properties	☐
Used foreach to loop through layer data	☐
Used tblsearch to check for existing layers	☐
Created and configured layers with command	☐

📌 Quick Tips

Tip	Why It Helps
Use itoa to convert numbers to strings	AutoLISP command only accepts strings
Add linetypes to your drawing before running	Avoids “invalid linetype” errors
Normalize layer names with strcase	Prevents mismatch due to capitalization
Assign lineweights as strings (e.g., "0.50")	Required format when using command

🧩 Real-World Applications

Use Case	Layer Groups	Why It Helps
Architectural base template	WALLS, TEXT, DOORS, HATCH	Standardizes layers from the start
Electrical layout setup	WIRES, DEVICES, NOTES	Ensures all symbols are on correct layers
Civil drawing layers	ROADS, CONTOURS, STRUCTURE	Creates consistency across sheets

📁 Files and Resources

File / Resource	Description
batch_layer_creator.lsp	The full script to create and configure layers
layer_template.docx	A sample list of layers with color, linetype, lineweight
linetype_loader_snippet.lsp	Snippet to load required linetypes from file

📖 Review Table

Function	Description	Example
command	Executes AutoCAD command	(command "-layer" "M" name ...)
tblsearch	Checks if a named table item exists	(tblsearch "LAYER" "TEXT")
foreach	Loops through a list	(foreach x myList ...)
strcase	Converts string case	(strcase name)
itoa	Converts integer to string	(itoa 5) → "5"