PEPS Macro Language

📘 Overview

PEPS (Production Engineering Productivity System) is a macro programming language used in CAD/CAM applications for automating manufacturing processes. This guide covers the essential syntax, commands, and best practices learned through extensive development work.

📁 File Structure

PEPS macro files use the .ovm extension. These are plain text files containing macro definitions and executable code.

Basic File Structure

; File: myMacro.ovm
; Description: Example macro file

mac myMacroName
    ; Local variable declarations (MUST be at top)
    local w_myReal
    local i_myInt
    local $_myString
    
    ; Executable code follows
    w_myReal = 10.5
    i_myInt = 42
    
endmac

⚠ Line Endings

When creating or editing .ovm files programmatically, you may need to ensure CRLF line endings for compatibility with the macro editor:

// In most editors, configure to use CRLF
// In code, explicitly use \r\n for newlines

📊 Variables

PEPS uses Hungarian notation prefixes to denote variable types:

📋 Variable Declaration Rules

✔ Correct

mac correctExample
    ; ALL locals declared at top
    local w_x
    local w_y
    local i_count
    
    ; Now executable code
    for i_count = 1 to 10
        w_x = i_count * 2
    next
endmac

✘ Wrong

mac wrongExample
    for i_count = 1 to 10
        local w_x  ; WRONG! Cannot declare inside loop
        w_x = i_count * 2
    next
endmac

🔄 System Scratch Variables

PEPS provides pre-declared system scratch variables for temporary data storage. Use these instead of declaring new globals:

➕ Math Operators

PEPS uses some non-standard operators:

📐 Math Functions

Trigonometric Functions

; Calculate angle from deltas
w_angle = atn2 w_dy w_dx   ; Note: y first, then x, NO comma

🪤 Parser Traps

The PEPS parser has some quirks that can cause unexpected errors:

Division in Complex Expressions

Remove spaces around / in complex bracketed expressions:

✔ Correct

w_result = (-w_b-w_disc)/(2*w_a)

✘ Wrong (can confuse parser)

w_result = (-w_b - w_disc) / (2 * w_a)  ; Spaces around / can cause issues

🔍 Value Extraction

Extracting values from geometry uses special syntax. There is no get p1 or get c1 command.

Point Coordinates

; Extract X and Y from point p1
w_x = xp1
w_y = yp1

; For other points
w_x = xp5    ; X coordinate of p5
w_y = yp99   ; Y coordinate of p99

Circle Properties

; Get circle center (assign to a point)
p99 = c1     ; p99 now holds the center of c1

; Get circle radius (assign to a real)
w_radius = c1   ; w_radius now holds the radius of c1

Point at Angle from Circle

; Get point on circle c1 at 45 degrees
p1 = b45 c1   ; b = bearing/angle

Distance Between Points

; Calculate distance from p1 to p2
w_dist = p1 p2

〰 Kurve Syntax

Kurves (curves) are sequences of connected spans (lines and arcs). Each span must be on its own line.

Basic Kurve Structure

kurve
    w_startX w_startY          ; Starting point
    w_endX1 w_endY1            ; Line to this point
    tw_endX2 w_endY2 w_ctrX w_ctrY   ; CW arc
    aw_endX3 w_endY3 w_ctrX w_ctrY   ; CCW arc
endkurve

Arc Modifiers

✔ Correct

tw_endX w_endY w_ctrX w_ctrY    ; t directly attached to w_endX
t-w_rad 0 0 0                   ; t attached to negative value

✘ Wrong

t w_endX w_endY w_ctrX w_ctrY   ; WRONG! Space after t
t -w_rad 0 0 0                  ; WRONG! Space after t

Complete Example

; Draw a rounded rectangle
kurve
    0 w_rad                      ; Start point
    0 (w_height-w_rad)            ; Line up left side
    aw_rad w_height 0 (w_height-w_rad)  ; CCW arc top-left
    (w_width-w_rad) w_height       ; Line across top
    aw_width (w_height-w_rad) (w_width-w_rad) (w_height-w_rad)  ; CCW arc top-right
    w_width w_rad                ; Line down right side
    a(w_width-w_rad) 0 (w_width-w_rad) w_rad  ; CCW arc bottom-right
    w_rad 0                      ; Line across bottom
    a0 w_rad w_rad w_rad         ; CCW arc bottom-left (closes)
endkurve

🎯 Geometry Modifiers

When creating geometry that intersects other elements, modifiers specify which solution to use:

🗑 Deleting Geometry

Delete ranges of geometry elements with this syntax:

; Delete spans s1 through s500
delete s1>500

; Delete circles c1 through c500
delete c1>500

; Delete points p1 through p500
delete p1>500

🔷 SLD Commands Overview

SLD (SoLiD) commands interface with the Parasolid geometry kernel for 3D solid modeling operations.

📦 SLD Primitives

SLD BLO (Block)

Creates a rectangular block (box) primitive.

sld blo w_xSize w_ySize w_zSize w_xPos w_yPos w_zPos i_ret

SLD CYL (Cylinder)

sld cyl w_radius w_height w_xPos w_yPos w_zPos i_ret

🔄 SLD CNV ENT (Convert Entity)

Converts between different geometry types.

sld cnv ent i_inputType i_outputType i_pickMode i_inputID i_outputID

Entity Type Codes

Pick Mode

Use i_pickMode = 1 for programmatic selection (no user interaction).

; Convert kurve k1 to sheet body
sld cnv ent 1 8 1 i_kurveId i_sheetId

⊕ SLD Boolean Operations

Single Body Operations

; Union
sld uni i_targetBody i_toolBody i_ret

; Intersection
sld int i_targetBody i_toolBody i_ret

; Subtraction
sld sub i_targetBody i_toolBody i_ret

Batch Boolean Operations

For better performance with multiple bodies, use VDM mode:

; Switch to VDM mode for batch operations
sld mode vdm

; Build tool set
sld pic lis clr           ; Clear pick list
sld put bod i_body1       ; Add bodies to set
sld put bod i_body2
sld put bod i_body3

; Perform batch union
sld uni i_targetBody i_toolSet i_resultSet

; Return to list mode
sld mode list

🔎 SLD Body Queries

Body Extent (Bounding Box)

sld body extent i_body w_xMin w_yMin w_zMin w_xMax w_yMax w_zMax

Get Last Created Body

sld ask bod las i_bodyId

Copy Body

sld copy body i_sourceBody i_destBody i_ret

Multi-Part Body Query

sld ask bod part i_body i_partNumber i_ret

◻ SLD Face Operations

Examine Face (SLD EXA FAC)

Query face properties and type.

sld exa fac i_faceId i_class ...

Face Class Codes

Face Removal / Hole Closing (SLD FAC REM)

Close holes in solid bodies by removing faces:

sld fac rem none i_faceSet 0 0 0 1 0 0 i_ret

✂ SLD SEC (Section)

Slice a solid body with a sheet surface.

sld sec i_body i_sheet i_ret

; Proper sectioning workflow
sld copy body i_original i_copy i_ret   ; Copy solid first
sld sec i_copy i_sheet i_ret           ; Section the copy
sld ask bod las i_newPiece             ; Get the new piece

📑 SLD Body Thicken

Thicken a sheet body into a solid.

sld body thicken i_count i_body w_startDist w_endDist i_ret

📐 SLD TAP (Taper)

Apply a taper (draft angle) to faces.

sld tap i_ws_body_set i_refFace x1 y1 z1 x2 y2 z2 w_angle i_ret

📍 SLD PMK (Position Marks)

Track body creation for later retrieval of newly created bodies.

; Start tracking
sld pmk on

; Create checkpoint
sld pmk now

; ... create some bodies ...

; Query what was created since checkpoint
sld ask new i_bodSet i_assSet i_bodCnt i_assCnt i_ret

; Stop tracking
sld pmk off

💾 VDM Storage Overview

VDM (Virtual Data Manager) provides persistent data storage within PEPS. Two access patterns exist:

➕ VDM ADD / GET

Direct access pattern using set numbers (no handle needed):

; Store a value
vdm add i_setNumber w_value

; Retrieve a value
vdm get i_setNumber w_value

📂 VDM File I/O

File-like access pattern using handles:

; Open for writing
vdm open i_handle "filename" "w"

; Write data
vdm write i_handle w_value

; Seek to position
vdm seek i_handle i_position

; Close handle
vdm close i_handle

; Open for reading
vdm open i_handle "filename" "r"

; Read data
vdm read i_handle w_value

; Check for end of file
vdm eof i_handle i_isEof

📸 VDM Body Snapshots

Track newly created bodies by comparing snapshots:

; Take snapshot before operation
fxBodiesSnapshot i_beforeSet

; ... perform operations that create bodies ...

; Take snapshot after operation
fxBodiesSnapshot i_afterSet

; Get list of newly created bodies
fxBodiesCreated i_beforeSet i_afterSet i_newBodiesSet

; Iterate through new bodies
vdm open i_handle i_newBodiesSet "r"
vdm eof i_handle i_done
while i_done == 0
    vdm read i_handle i_bodyId
    ; Process body...
    vdm eof i_handle i_done
wend
vdm close i_handle

📁 Macro Organization

Recommended Structure

project/
+-- main.ovm              ; Entry point
+-- utils/
|   +-- mathUtils.ovm     ; Shared math functions
|   +-- geometryUtils.ovm ; Shared geometry helpers
|   +-- vdmUtils.ovm      ; Shared VDM operations
+-- modules/
|   +-- featureA.ovm      ; Feature-specific logic
|   +-- featureB.ovm
+-- config/
    +-- constants.ovm     ; Global constants

🔄 Transform Order

When rotating geometry around a point, the correct transform order is:

1. Translate to origin (T-1) - move the rotation point to 0,0,0
2. Rotate (R) - apply the rotation
3. Translate back (T) - move back to original position

Mathematically: Result = T * R * T-1 * Point

; Rotate body around point (cx, cy, cz) by angle

; Step 1: Translate to origin
sld tra i_body -w_cx -w_cy -w_cz

; Step 2: Rotate
sld rot i_body 0 0 1 w_angle   ; Rotate around Z axis

; Step 3: Translate back
sld tra i_body w_cx w_cy w_cz

⚠ Common Pitfalls

🚫 Commands to Avoid

SLD BLE (Blend)

The sld ble command is unreliable. Use this alternative workflow instead:

; Instead of sld ble, use this pattern:

; 1. Create kurve geometry
kurve
    ...
endkurve

; 2. Convert kurve to sheet
sld cnv ent 1 8 1 i_kurveId i_sheetId

; 3. Thicken the sheet
sld body thicken 1 i_sheetId w_thickness 0 i_ret