fix(engine): 支持倒角角度参数并新增回归测试

backend/engine/cdsl_engine/runtime.py

@@ -619,12 +619,21 @@ def _execute_chamfer(node: FeaturePlanNode, session: ExecutionSession) -> Featur
     distance = float(node.params.get("distance_mm") or 0)
     if distance <= 0:
         raise ValueError("chamfer distance_mm must be > 0")
-    # 3. 解析目标边（支持相切传播），执行倒角；distance_2_mm 提供时产生非对称倒角。
+    # 3. 解析第二距离与角度（importer 对 SolidWorks Distance-Angle 倒角产出
+    #    angle_rad，单位为弧度）。第二距离 = 主距离 * tan(angle)；angle=45° 时
+    #    tan=1，退化为等距倒角（与历史行为一致，零回归）。
+    #    注意：build123d 的 length/length2 侧向分配依赖面的枚举顺序，对非 45°
+    #    倒角仅保证量级正确，距离所在侧可能反转。
+    distance_2 = node.params.get("distance_2_mm")
+    angle_rad = node.params.get("angle_rad")
+    if distance_2 is None and angle_rad is not None:
+        distance_2 = distance * math.tan(float(angle_rad))
+    # 4. 解析目标边（支持相切传播），执行倒角。
     body = session.adapter.chamfer(
-        session.body, distance, node.params.get("distance_2_mm"),
+        session.body, distance, distance_2,
         _selector_edges(node, session, tangent_propagation=bool(node.params.get("tangent_propagation"))),
     )
-    # 4. 登记新主体并返回结果。
+    # 5. 登记新主体并返回结果。
     session.register_body(node.feature_id, body, replay_node=node)
     return session.result(node)
 

backend/tests/test_engine_runtime_foundation.py

@@ -658,6 +658,40 @@ class EngineRuntimeFoundationTests(unittest.TestCase):
         self.assertLess(chamfer_result["volume_mm3"], baseline["volume_mm3"])
         self.assertAlmostEqual(pattern_result["volume_mm3"], 1000 - 3 * 10 * 3.141592653589793, places=5)
 
+    def test_chamfer_consumes_angle_rad_instead_of_silent_45_degree_fallback(self) -> None:
+        from cdsl_engine.runtime import rebuild_cdsl
+
+        import math
+
+        base = self._base_block()
+        with tempfile.TemporaryDirectory() as directory:
+            root = Path(directory)
+            baseline = rebuild_cdsl(base, root / "baseline.step")
+            edge = next(item for item in baseline["topology_records"] if item["kind"] == "edge")
+            selector = {
+                "kind": "edge", "stable_id": "edge", "source": "solidworks", "confidence": 1,
+                "owner_feature_id": "base_add", "geometry": edge["geometry"],
+            }
+
+            equal = deepcopy(base)
+            equal["features"].append({
+                "id": "chamfer_45", "atomic_id": "chamfer", "depends_on": ["base_add"],
+                "params": {"distance_mm": 1, "angle_rad": math.pi / 4}, "selectors": [deepcopy(selector)],
+            })
+            equal_result = rebuild_cdsl(equal, root / "chamfer-45.step")
+            # 45° Distance-Angle 等价于等距倒角：tan(45°)=1，切掉 0.5*1*1*10=5 mm³。
+            self.assertAlmostEqual(equal_result["volume_mm3"], 1000 - 5, places=5)
+
+            slanted = deepcopy(base)
+            slanted["features"].append({
+                "id": "chamfer_30", "atomic_id": "chamfer", "depends_on": ["base_add"],
+                "params": {"distance_mm": 1, "angle_rad": math.pi / 6}, "selectors": [deepcopy(selector)],
+            })
+            slanted_result = rebuild_cdsl(slanted, root / "chamfer-30.step")
+            # 30°：第二距离 = 1*tan(30°)≈0.577，切掉 0.5*1*0.577*10≈2.887 mm³，
+            # 体积明显大于 45° 等距倒角（995），验证 angle_rad 被消费而非静默 45°。
+            self.assertAlmostEqual(slanted_result["volume_mm3"], 1000 - 0.5 * math.tan(math.pi / 6) * 10, places=5)
+
     def test_linear_pattern_replays_hole_with_explicit_host_frame(self) -> None:
         from cdsl_engine.runtime import rebuild_cdsl