Add detect_mesh_features: crease-ring feature outlines (#108)

README.md

@@ -8,7 +8,7 @@ MCP server that gives LLMs the ability to author, inspect, and iterate on 3D CAD
 
 Part of the [OCCTSwift ecosystem](https://github.com/SecondMouseAU/OCCTSwift/blob/main/docs/ecosystem.md) — see the ecosystem map for how this package sits on top of the kernel, viewport, bridge, and AIS layers. SemVer-stable from v1.0.0.
 
-The Swift implementation calls OCCT directly in-process — no subprocess, no JSONL marshalling — and exposes 73 typed MCP tools that cover authoring, scene reads, mutation, introspection, construction, analysis, I/O, mesh, drawing, selection / remap, mesh-zone analysis, mesh inspection, alignment, and dimension overlays.
+The Swift implementation calls OCCT directly in-process — no subprocess, no JSONL marshalling — and exposes 74 typed MCP tools that cover authoring, scene reads, mutation, introspection, construction, analysis, I/O, mesh, drawing, selection / remap, mesh-zone analysis, mesh inspection, alignment, and dimension overlays.
 
 ## How It Works
 
@@ -23,7 +23,7 @@ For novel geometry the typed tools don't cover, the LLM falls back to `execute_s
 
 ## Tools
 
-73 tools, organized below. Call `get_api_reference({ category: "mcp_tools" })` to dump every tool's JSON Schema in one shot — useful for LLM auto-discovery. Most flows can answer "what's the volume?", "make it red", "boolean-subtract these", "render a preview", "add a dimension between these two faces", "export to STEP", and "draw this" without ever touching `execute_script`.
+74 tools, organized below. Call `get_api_reference({ category: "mcp_tools" })` to dump every tool's JSON Schema in one shot — useful for LLM auto-discovery. Most flows can answer "what's the volume?", "make it red", "boolean-subtract these", "render a preview", "add a dimension between these two faces", "export to STEP", and "draw this" without ever touching `execute_script`.
 
 ### Authoring
 
@@ -124,6 +124,7 @@ The mesh-domain check-list / measurement surface (Phase 2 of the mesh-analysis e
 | `detect_symmetry` | Detect reflective (mirror-plane) symmetry: 3 PCA candidate planes through the area-weighted centroid, each verified by reflecting sampled points and measuring their residual distance back to the surface. Rotational/axis symmetry detection is deferred to a later phase |
 | `align_bodies` (#104) | GOM-style alignment: register a source body onto a reference body via point-to-plane ICP (PCA pre-align + normal-space sampling + trimmed correspondence). `mode: "bestFit"` (default, full pipeline) or `"preAlign"` (coarse PCA/bbox pose only). Returns the recovered transform (row-major, translation + axis-angle rotation) and residual stats; `apply: true` writes it onto the source body in place with the same history semantics as `transform_body`. The step scan-vs-CAD deviation tools need before their numbers mean anything |
 | `mesh_curvature` | Per-vertex discrete curvature (Rusinkiewicz per-face tensor) over a body's own welded mesh: principal curvatures k1/k2, mean, gaussian, plus a colored render (`colorBy`) and bounded stats (medians, flatFraction, highCurvatureFraction). No reference body needed |
+| `detect_mesh_features` (#108) | Crease-ring feature outlines (doors, panels, window returns, recesses) on a raw scan mesh via dihedral-fold-edge detection: welds the mesh, chains fold edges exceeding `minAngleDegrees` into closed rings and open paths (largest-first), for meshes where `recognize_features` (BREP/AAG) has no B-rep structure to work against. Junction-aware (Y/T intersections split cleanly). Reports each ring's `containingZones` when `segment_mesh_zones` has already run for the body. Optional render: the surface plus each ring as its own categorically-colored wireframe overlay |
 
 ### Selection & remap
 
@@ -195,7 +196,7 @@ LLM read/write over an attributed reconstruction graph — annotate per-node dec
 
 This repo ships two implementations side-by-side:
 
-- **Swift** (`Sources/`, `Package.swift`) — the **primary** server. In-process against OCCTSwift / OCCTSwiftMesh / OCCTSwiftTools / OCCTSwiftAIS / DrawingComposer using the [official Swift MCP SDK](https://swiftpackageindex.com/modelcontextprotocol/swift-sdk). 73 tools. macOS 15+ (the OCCT.xcframework arm64 platform).
+- **Swift** (`Sources/`, `Package.swift`) — the **primary** server. In-process against OCCTSwift / OCCTSwiftMesh / OCCTSwiftTools / OCCTSwiftAIS / DrawingComposer using the [official Swift MCP SDK](https://swiftpackageindex.com/modelcontextprotocol/swift-sdk). 74 tools. macOS 15+ (the OCCT.xcframework arm64 platform).
 - **Node / TypeScript** (`src/`, `dist/`) — the original implementation. Shells out to the `occtkit` CLI for everything Swift-side. 37 tools (the pre-v0.4 surface; selection / remap / annotations are Swift-only). Useful if you can't run a macOS binary.
 
 Both speak stdio MCP and read/write the same manifest format.

Sources/OCCTMCPCore/Server.swift

@@ -14,7 +14,7 @@ public enum OCCTMCPVersion {
     public static let serverName = "occtmcp"
     /// Keep in step with the release tag: clients report this string, and a
     /// stale value makes version triage ambiguous (noted in #75).
-    public static let serverVersion = "1.25.0"
+    public static let serverVersion = "1.26.0"
 }
 
 /// Shared by the three tools that share DeviationTools' signed-distance engine
@@ -1407,6 +1407,24 @@ func catalogTools() -> [Tool] {
                 "additionalProperties": .bool(false),
             ])
         ),
+        Tool(
+            name: "detect_mesh_features",
+            description: "Crease-ring feature outlines (doors, panels, window returns, recesses) on a raw scan mesh via dihedral-fold-edge detection (OCCTSwiftMesh.Mesh.creaseEdges, OCCTSwiftMesh#28), for meshes where recognize_features (BREP/AAG) cannot operate at all — a scanned/STL body has no B-rep face/edge structure to recognize features against. Meshes the body, welds it (MANDATORY precondition: on unwelded input every edge is a boundary edge and the dihedral angle is undefined, so zero creases are ever found regardless of the body's actual geometry), then chains dihedral-fold edges exceeding minAngleDegrees into closed rings (e.g. a door outline) and open paths (a crease running off an open mesh boundary), largest-first. Y/T junctions where 3+ creases meet split cleanly into separate rings/paths rather than being wandered through arbitrarily; leftover edges that couldn't be chained are counted in unchainedCreaseEdgeCount, never dropped. When segment_mesh_zones has already been run for this body (same mesh state, verified by signature), each ring reports containingZones: the zone id(s) whose triangles are incident to the ring's own vertices, majority first — omitted with a warning if the zone table is stale or the internal weld guard failed, omitted silently (no warning) if no zones are registered for this body at all. Optional render: the body surface as a neutral translucent grey mesh, plus each ring as its own categorically-colored wireframe overlay with a legend.",
+            inputSchema: .object([
+                "type": .string("object"),
+                "properties": .object([
+                    "bodyId": .object(["type": .string("string")]),
+                    "minAngleDegrees": .object(["type": .string("number"), "exclusiveMinimum": .double(0), "maximum": .double(180), "description": .string("Dihedral fold-angle threshold in degrees; an edge whose two triangles' normals differ by at least this much is a crease. Default 30.")]),
+                    "maxRings": .object(["type": .string("integer"), "minimum": .int(1), "description": .string("Cap on returned rings/paths; the largest (by length) are kept, the rest counted in a warning. Default 64.")]),
+                    "deflection": .object(["type": .string("number"), "description": .string("Mesh linear deflection. Default 0.5% of the body's bbox diagonal.")]),
+                    "render": .object(["type": .string("boolean"), "description": .string("Render the body with each ring overlaid as a categorically-colored wireframe, with a legend. Default true.")]),
+                    "renderPath": .object(["type": .string("string"), "description": .string("Override the default render path (<output_dir>/<bodyId>_features.png).")]),
+                    "options": .object(["type": .string("object"), "description": .string("Render options — same shape as render_preview.options (camera, width, height, background).")]),
+                ]),
+                "required": .array([.string("bodyId")]),
+                "additionalProperties": .bool(false),
+            ])
+        ),
     ]
 }
 
@@ -2334,6 +2352,27 @@ func dispatch(callName: String, arguments: [String: Value]) async -> CallTool.Re
             options: parseRenderOptions(arguments["options"])
         ).asCallToolResult()
 
+    case "detect_mesh_features":
+        guard let bodyId = arguments["bodyId"]?.stringValue else {
+            return ToolText("detect_mesh_features requires `bodyId`.", isError: true).asCallToolResult()
+        }
+        // Dispatch-level guard (the #106 convention): an invalid minAngleDegrees must error here
+        // too, not just inside the tool function — this is the layer an MCP client's own schema
+        // validation can be bypassed at.
+        let minAngle = arguments["minAngleDegrees"]?.numberValue ?? 30
+        guard minAngle > 0, minAngle <= 180 else {
+            return ToolText("detect_mesh_features: minAngleDegrees must be in (0, 180].", isError: true).asCallToolResult()
+        }
+        return await MeshFeatureTools.detectMeshFeatures(
+            bodyId: bodyId,
+            minAngleDegrees: minAngle,
+            maxRings: arguments["maxRings"]?.intValue ?? 64,
+            deflection: arguments["deflection"]?.numberValue,
+            render: arguments["render"]?.boolValue ?? true,
+            renderPath: arguments["renderPath"]?.stringValue,
+            options: parseRenderOptions(arguments["options"])
+        ).asCallToolResult()
+
     case "fit_primitives":
         guard let bodyId = arguments["bodyId"]?.stringValue else {
             return ToolText("fit_primitives requires `bodyId`.", isError: true).asCallToolResult()

Sources/OCCTMCPCore/Tools/FitPrimitivesTools.swift

@@ -251,7 +251,7 @@ public enum FitPrimitivesTools {
             return IntrospectionTools.encode(FitReport(
                 bodyId: bodyId, zoneId: zoneId, strategy: strategyLabel, strategyScores: strategyScores,
                 primitives: [], uncoveredFraction: uncoveredFraction, renderPath: nil,
-                warnings: warnings + ["No primitive met minSupportTriangles; nothing to report."]
+                warnings: warnings + ["No primitives to report: none met minSupportTriangles, or maxPrimitives removed them all (see any cap warning above)."]
             ))
         }