Implement STEP file merging using model_step_url

lib/index.ts

@@ -41,6 +41,8 @@ import {
   type Ref,
 } from "stepts"
 import { generateComponentMeshes } from "./mesh-generation"
+import { mergeExternalStepModels } from "./step-model-merger"
+import { normalizeStepNumericExponents } from "./step-text-utils"
 
 export interface CircuitJsonToStepOptions {
   /** Board width in mm (optional if pcb_board is present) */
@@ -500,22 +502,40 @@ export async function circuitJsonToStep(
   // Array to hold all solids (board + optional components)
   const allSolids: Ref<ManifoldSolidBrep>[] = [solid]
 
-  // Generate component mesh if requested
+  let handledComponentIds = new Set<string>()
+  let handledPcbComponentIds = new Set<string>()
+
+  if (options.includeComponents && options.includeExternalMeshes) {
+    const mergeResult = await mergeExternalStepModels({
+      repo,
+      circuitJson,
+      boardThickness,
+    })
+    handledComponentIds = mergeResult.handledComponentIds
+    handledPcbComponentIds = mergeResult.handledPcbComponentIds
+    allSolids.push(...mergeResult.solids)
+  }
+
+  // Generate component mesh fallback if requested
   if (options.includeComponents) {
     const componentSolids = await generateComponentMeshes({
       repo,
       circuitJson,
       boardThickness,
       includeExternalMeshes: options.includeExternalMeshes,
+      excludeCadComponentIds: handledComponentIds,
+      excludePcbComponentIds: handledPcbComponentIds,
     })
     allSolids.push(...componentSolids)
   }
 
   // Add presentation/styling for all solids
   const styledItems: Ref<StyledItem>[] = []
 
-  for (const solidRef of allSolids) {
-    const color = repo.add(new ColourRgb("", 0.2, 0.6, 0.2))
+  allSolids.forEach((solidRef, index) => {
+    const isBoard = index === 0
+    const [r, g, b] = isBoard ? [0.2, 0.6, 0.2] : [0.75, 0.75, 0.75]
+    const color = repo.add(new ColourRgb("", r, g, b))
     const fillColor = repo.add(new FillAreaStyleColour("", color))
     const fillStyle = repo.add(new FillAreaStyle("", [fillColor]))
     const surfaceFill = repo.add(new SurfaceStyleFillArea(fillStyle))
@@ -524,7 +544,7 @@ export async function circuitJsonToStep(
     const presStyle = repo.add(new PresentationStyleAssignment([surfaceUsage]))
     const styledItem = repo.add(new StyledItem("", [presStyle], solidRef))
     styledItems.push(styledItem)
-  }
+  })
 
   repo.add(
     new MechanicalDesignGeometricPresentationRepresentation(
@@ -541,5 +561,6 @@ export async function circuitJsonToStep(
   repo.add(new ShapeDefinitionRepresentation(productDefShape, shapeRep))
 
   // Generate and return STEP file text
-  return repo.toPartFile({ name: productName })
+  const stepText = repo.toPartFile({ name: productName })
+  return normalizeStepNumericExponents(stepText)
 }

lib/mesh-generation.ts

@@ -29,6 +29,10 @@ export interface MeshGenerationOptions {
   boardThickness: number
   /** Include external model meshes from model_*_url fields (default: false) */
   includeExternalMeshes?: boolean
+  /** Cad component ids already handled by STEP merging */
+  excludeCadComponentIds?: Set<string>
+  /** PCB component ids already handled by STEP merging */
+  excludePcbComponentIds?: Set<string>
 }
 
 /**
@@ -255,13 +259,32 @@ export async function generateComponentMeshes(
     circuitJson,
     boardThickness,
     includeExternalMeshes = false,
+    excludeCadComponentIds,
+    excludePcbComponentIds,
   } = options
   const solids: Ref<ManifoldSolidBrep>[] = []
 
   try {
     // Filter circuit JSON and optionally remove model URLs
     const filteredCircuitJson = circuitJson
-      .filter((e) => e.type !== "pcb_board")
+      .filter((e) => {
+        if (e.type === "pcb_board") return false
+        if (
+          e.type === "cad_component" &&
+          e.cad_component_id &&
+          excludeCadComponentIds?.has(e.cad_component_id)
+        ) {
+          return false
+        }
+        if (
+          e.type === "pcb_component" &&
+          e.pcb_component_id &&
+          excludePcbComponentIds?.has(e.pcb_component_id)
+        ) {
+          return false
+        }
+        return true
+      })
       .map((e) => {
         if (!includeExternalMeshes && e.type === "cad_component") {
           // Remove model_*_url fields to avoid hanging on external model fetches