From 370a2d95cc24bbb8097699b6ddb68f57dd712c53 Mon Sep 17 00:00:00 2001
From: Nicolas Predella <nicolas@predella.me>
Date: Tue, 2 Jun 2026 10:18:25 +0300
Subject: [PATCH] slice angled

---
 core/nodeslicer/nodes/path.py | 27 +++++++++++++++++++--------
 doc/NODES.md                  |  2 +-
 doc/USER_GUIDE.md             |  2 +-
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/core/nodeslicer/nodes/path.py b/core/nodeslicer/nodes/path.py
index 85e5c8d..cdc8c83 100644
--- a/core/nodeslicer/nodes/path.py
+++ b/core/nodeslicer/nodes/path.py
@@ -38,21 +38,27 @@ class SLICENODE_SliceShells(SliceNode):
     def init(self, context):
         self.add_input("SLICESOCK_Mesh")
         self.add_input("SLICESOCK_Float", "Layer Height").value = 0.2
+        self.add_input("SLICESOCK_VectorRotation", "Rotation")
         self.add_output("SLICESOCK_Paths")
 
     def evaluate_output(self, socket_name: str, **_kwargs) -> SlicePaths:
         if socket_name != "Paths": return SlicePaths()
 
-        slicing_collection: SlicingCollection | None = self.resolve("Mesh")
+        coll: SlicingCollection | None = self.resolve("Mesh")
         layer_height: float = self.resolve("Layer Height")
+        rotation: Any = self.resolve("Rotation") or (0.0, 0.0, 0.0)
 
-        if not slicing_collection: return SlicePaths()
+        if not coll: return SlicePaths()
 
         merged_object = SlicingObject()
-        coll: SlicingCollection = self.resolve("Mesh")
-        if coll: 
-            for obj in coll.objects:
-                merged_object.mesh = np.concatenate([merged_object.mesh, obj.mesh], axis=0)
+        for obj in coll.objects:
+            merged_object.mesh = np.concatenate([merged_object.mesh, obj.mesh], axis=0)
+
+        if rotation and any(rotation):
+            from mathutils import Euler
+            mat = np.array(Euler(rotation).to_matrix().inverted())
+            merged_object.mesh[:, :3, :] = merged_object.mesh[:, :3, :] @ mat.T
+            merged_object.mesh[:, 3:4, :] = merged_object.mesh[:, 3:4, :] @ mat.T
 
         min_z = merged_object.mesh[:,0:3,2:3].min()
         from math import floor
@@ -63,9 +69,14 @@ class SLICENODE_SliceShells(SliceNode):
 
         slices_group: list[list[np.ndarray]] | None = slice_at_range([merged_object.mesh], z_values)
         assert slices_group
-        slices = slices_group[0]
+        slices = SlicePaths(slices_group[0])
 
-        return SlicePaths(slices)
+        if rotation and any(rotation):
+            from mathutils import Euler
+            mat_inv = np.array(Euler(rotation).to_matrix())
+            slices = slices.transform(mat_inv)
+
+        return slices
 
 @register_class
 class SLICENODE_BufferShells(SliceNode):
diff --git a/doc/NODES.md b/doc/NODES.md
index 40acade..fcbda3c 100644
--- a/doc/NODES.md
+++ b/doc/NODES.md
@@ -57,7 +57,7 @@ All nodes are found in the **Add (Shift+A)** menu under the **SliceNodes** categ
     - **Extrusion Multiplier Attribute**: Mesh attribute to use for per-segment extrusion rates.
     - **Feedrate Attribute**: Mesh attribute to use for per-segment feedrates.
     - **Extra Attributes**: Dictionary mapping mesh attribute names to custom G-code prefixes (e.g., `opening_size` -> `S`).
-- **Slice Shells**: Slices a `SlicingObject` into 2D `SlicePaths` at a given layer height.
+- **Slice Shells**: Slices a `SlicingObject` into 2D `SlicePaths` at a given layer height. Supports rotation for slicing at an angle.
 - **Buffer Shells**: Offsets/buffers 2D `SlicePaths`. Supports rotated offsetting and multiple miter types.
 - **Infill**: Generates a cross-hatch grid or parallel lines clipped by boundary paths. 
     - **Infill Type**: Switch between **Grid** (cross-hatch) and **Rectilinear** (alternating parallel lines).
diff --git a/doc/USER_GUIDE.md b/doc/USER_GUIDE.md
index 12fcb37..34bcc0d 100644
--- a/doc/USER_GUIDE.md
+++ b/doc/USER_GUIDE.md
@@ -67,5 +67,5 @@ Once you are happy with the preview:
 
 ## 5. Tips for Success
 *   **Scale**: The slicer treats 1 Blender unit as 1 meter, but scales everything to **mm** for the G-code output.
-*   **Orientation**: The slicer currently assumes your object is oriented correctly for printing (Z is up).
+*   **Orientation**: The slicer currently assumes your object is oriented correctly for printing (Z is up). You can use the **Rotation** input on the **Slice Shells** node to slice at an angle if needed.
 *   **Performance**: For very complex meshes, the "Get Mesh" and "Slice Shells" nodes might take a moment to compute. The result is cached, so changing settings further down the chain (like Infill density) will be much faster.