From fadbea5dfe2bf0cfafd1dbfc0836493672339350 Mon Sep 17 00:00:00 2001
From: MarekSpodBiedry <73122968+MarekSpodBiedry@users.noreply.github.com>
Date: Sat, 10 Oct 2026 18:12:16 +0200
Subject: [PATCH] Keep elevations when EXPLODE splits a 3D polyline (#88)
 (#138)

---
 crates/engine/src/cmd/modify.rs        |  5 ++++-
 crates/engine/src/cmd/modify2_tests.rs | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/crates/engine/src/cmd/modify.rs b/crates/engine/src/cmd/modify.rs
index feb087fd..600cea77 100644
--- a/crates/engine/src/cmd/modify.rs
+++ b/crates/engine/src/cmd/modify.rs
@@ -891,7 +891,10 @@ pub(crate) fn explode_kind(d: &cadcraft_doc::Drawing, e: &Entity) -> Option<Vec<
         EntityKind::Polyline3d(p) => Some(
             p.points
                 .windows(2)
-                .filter_map(|w| Some(Entity { handle: Handle(0), common: e.common.clone(), kind: line(w.first()?.xy(), w.get(1)?.xy()) }))
+                .filter_map(|w| {
+                    let kind = EntityKind::Line(cadcraft_doc::Line { a: *w.first()?, b: *w.get(1)? });
+                    Some(Entity { handle: Handle(0), common: e.common.clone(), kind })
+                })
                 .collect(),
         ),
         EntityKind::MText(m) => Some(
diff --git a/crates/engine/src/cmd/modify2_tests.rs b/crates/engine/src/cmd/modify2_tests.rs
index addb479f..f7f547ea 100644
--- a/crates/engine/src/cmd/modify2_tests.rs
+++ b/crates/engine/src/cmd/modify2_tests.rs
@@ -606,3 +606,21 @@ fn textedit_json_and_command_line() {
     assert!(s.running.is_none());
     assert!(matches!(kind(&s, &t), EntityKind::Text(x) if x.value == "hello world"));
 }
+
+#[test]
+fn explode_polyline3d_keeps_elevations() {
+    let mut s = Session::new();
+    let p = h(&s.execute("3dpoly", &json!({"points": [[0, 0, 5], [1, 0, 6], [1, 1, 7]]})).unwrap());
+    s.execute("explode", &json!({"handles": [p]})).unwrap();
+    let lines: Vec<(f64, f64)> = s
+        .doc()
+        .unwrap()
+        .model
+        .iter()
+        .filter_map(|e| match &e.kind {
+            EntityKind::Line(l) => Some((l.a.z, l.b.z)),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(lines, vec![(5.0, 6.0), (6.0, 7.0)]);
+}