feat(render): solid fill for PolyfaceMesh and PolygonMesh entities

PolyfaceMesh and PolygonMesh were wireframe-only. They now render with
the same flat-color solid fill as Face3D entities.

- Add fill_tris: Vec<[f32;3]> to TruckEntity and WireModel
- PolyfaceMesh: fan-triangulate each face into fill_tris
- PolygonMesh: triangulate each grid quad into fill_tris
- tessellate.rs Lines branch: apply world_offset to fill_tris
- Face3DGpu::from_wires: collect fill_tris from all wires in addition
  to Face3D key_vertices quads
- upload_face3d: pass all_wires so fill_tris are batched into one draw call

src/app/update.rs

@@ -1376,6 +1376,7 @@ impl H7CAD {
                                     aabb: crate::scene::WireModel::UNBOUNDED_AABB,
                                     plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                                 };
                                 previews.push(guide);
                             }

src/entities/arc.rs

@@ -87,6 +87,7 @@ fn to_truck(arc: &Arc) -> TruckEntity {
             snap_pts: vec![(cv, SnapHint::Center)],
             tangent_geoms: vec![tangent],
             key_vertices: vec![],
+            fill_tris: vec![],
         };
     }
 
@@ -101,6 +102,7 @@ fn to_truck(arc: &Arc) -> TruckEntity {
         snap_pts: vec![(cv, SnapHint::Center)],
         tangent_geoms: vec![tangent],
         key_vertices: vec![],
+        fill_tris: vec![],
     }
 }
 

src/entities/attribute.rs

@@ -42,6 +42,7 @@ impl TruckConvertible for AttributeDefinition {
             snap_pts: vec![(snap_pt, SnapHint::Insertion)],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         })
     }
 }
@@ -146,6 +147,7 @@ impl TruckConvertible for AttributeEntity {
             snap_pts: vec![(snap_pt, SnapHint::Insertion)],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         })
     }
 }

src/entities/circle.rs

@@ -91,6 +91,7 @@ fn to_truck(circle: &Circle) -> TruckEntity {
             snap_pts,
             tangent_geoms: vec![tangent],
             key_vertices: vec![],
+            fill_tris: vec![],
         };
     }
 
@@ -104,6 +105,7 @@ fn to_truck(circle: &Circle) -> TruckEntity {
         snap_pts,
         tangent_geoms: vec![tangent],
         key_vertices: vec![],
+        fill_tris: vec![],
     }
 }
 

src/entities/ellipse.rs

@@ -102,6 +102,7 @@ fn to_truck(ell: &Ellipse) -> TruckEntity {
             snap_pts,
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         }
     } else {
         let n = 32usize;
@@ -133,6 +134,7 @@ fn to_truck(ell: &Ellipse) -> TruckEntity {
             snap_pts: vec![(center_v3, SnapHint::Center)],
             tangent_geoms: vec![],
             key_vertices,
+            fill_tris: vec![],
         }
     }
 }

src/entities/leader.rs

@@ -64,6 +64,7 @@ fn to_truck(leader: &Leader) -> TruckEntity {
         snap_pts: vec![],
         tangent_geoms: tangents,
         key_vertices: key_verts,
+        fill_tris: vec![],
     }
 }
 

src/entities/line.rs

@@ -50,6 +50,7 @@ fn to_truck(line: &Line) -> TruckEntity {
             snap_pts: vec![],
             tangent_geoms: vec![tangent],
             key_vertices: kv,
+            fill_tris: vec![],
         };
     }
 
@@ -61,6 +62,7 @@ fn to_truck(line: &Line) -> TruckEntity {
         snap_pts: vec![],
         tangent_geoms: vec![tangent],
         key_vertices: kv,
+        fill_tris: vec![],
     }
 }
 

src/entities/lwpolyline.rs

@@ -106,7 +106,7 @@ fn thick_segments(
             pts.push(off(last));
         }
     }
-    TruckEntity { object: TruckObject::Lines(pts), snap_pts: vec![], tangent_geoms: tangents, key_vertices: key_verts }
+    TruckEntity { object: TruckObject::Lines(pts), snap_pts: vec![], tangent_geoms: tangents, key_vertices: key_verts, fill_tris: vec![] }
 }
 
 fn to_truck(pline: &LwPolyline) -> TruckEntity {
@@ -117,6 +117,7 @@ fn to_truck(pline: &LwPolyline) -> TruckEntity {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         };
     }
 
@@ -237,6 +238,7 @@ fn to_truck(pline: &LwPolyline) -> TruckEntity {
             snap_pts: vec![],
             tangent_geoms: tgs,
             key_vertices: kv,
+            fill_tris: vec![],
         };
     }
 
@@ -305,6 +307,7 @@ fn to_truck(pline: &LwPolyline) -> TruckEntity {
         snap_pts: vec![],
         tangent_geoms: tangents,
         key_vertices: key_verts,
+        fill_tris: vec![],
     }
 }
 

src/entities/mesh.rs

@@ -64,6 +64,7 @@ impl TruckConvertible for Face3D {
             ],
             tangent_geoms: vec![],
             key_vertices: vec![p0, p1, p2, p3],
+            fill_tris: vec![],
         })
     }
 }
@@ -182,9 +183,9 @@ impl TruckConvertible for PolygonMesh {
         };
 
         let mut pts: Vec<[f32; 3]> = Vec::new();
+        let mut fill_tris: Vec<[f32; 3]> = Vec::new();
 
         // Rows (M direction).
-        let m_end = if closed_m { m } else { m - 1 };
         for i in 0..m {
             pts.push([f32::NAN; 3]);
             for j in 0..n {
@@ -196,7 +197,6 @@ impl TruckConvertible for PolygonMesh {
         }
 
         // Columns (N direction).
-        let n_end = if closed_n { n } else { n - 1 };
         for j in 0..n {
             pts.push([f32::NAN; 3]);
             for i in 0..m {
@@ -206,13 +206,26 @@ impl TruckConvertible for PolygonMesh {
                 pts.push(pt(0, j));
             }
         }
-        let _ = (m_end, n_end); // suppress warnings
+
+        // Fill: triangulate each grid quad (two triangles per cell).
+        let mi = if closed_m { m } else { m - 1 };
+        let ni = if closed_n { n } else { n - 1 };
+        for i in 0..mi {
+            for j in 0..ni {
+                let p00 = pt(i, j);
+                let p10 = pt((i + 1) % m, j);
+                let p01 = pt(i, (j + 1) % n);
+                let p11 = pt((i + 1) % m, (j + 1) % n);
+                fill_tris.extend_from_slice(&[p00, p10, p11, p00, p11, p01]);
+            }
+        }
 
         Some(TruckEntity {
             object: TruckObject::Lines(pts),
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris,
         })
     }
 }
@@ -294,6 +307,7 @@ impl TruckConvertible for PolyfaceMesh {
         };
 
         let mut pts: Vec<[f32; 3]> = Vec::new();
+        let mut fill_tris: Vec<[f32; 3]> = Vec::new();
 
         for face in &self.faces {
             // Indices: 0 means unused. Negative = invisible edge (still render for wireframe).
@@ -313,6 +327,15 @@ impl TruckConvertible for PolyfaceMesh {
             }
             // Close the face polygon.
             pts.push(verts[0]);
+
+            // Fan-triangulate the face for solid fill.
+            if verts.len() >= 3 {
+                for i in 1..(verts.len() - 1) {
+                    fill_tris.push(verts[0]);
+                    fill_tris.push(verts[i]);
+                    fill_tris.push(verts[i + 1]);
+                }
+            }
         }
 
         Some(TruckEntity {
@@ -320,6 +343,7 @@ impl TruckConvertible for PolyfaceMesh {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris,
         })
     }
 }

src/entities/mline.rs

@@ -109,6 +109,7 @@ impl TruckConvertible for MLine {
             snap_pts,
             tangent_geoms: vec![],
             key_vertices: key_verts,
+            fill_tris: vec![],
         })
     }
 }

src/entities/mtext.rs

@@ -177,6 +177,7 @@ fn to_truck(t: &MText, document: &acadrust::CadDocument) -> TruckEntity {
         snap_pts: vec![(insertion, SnapHint::Insertion)],
         tangent_geoms: vec![],
         key_vertices: vec![],
+        fill_tris: vec![],
     }
 }
 

src/entities/multileader.rs

@@ -156,6 +156,7 @@ fn to_truck(ml: &MultiLeader, document: &acadrust::CadDocument) -> Option<TruckE
         snap_pts,
         tangent_geoms: tangents,
         key_vertices: key_verts,
+        fill_tris: vec![],
     })
 }
 

src/entities/ole2frame.rs

@@ -22,6 +22,7 @@ fn to_truck(ole: &Ole2Frame) -> TruckEntity {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         };
     }
 
@@ -42,6 +43,7 @@ fn to_truck(ole: &Ole2Frame) -> TruckEntity {
         snap_pts: vec![(center, SnapHint::Center)],
         tangent_geoms: vec![],
         key_vertices: vec![[x0, y0, z], [x1, y1, z]],
+        fill_tris: vec![],
     }
 }
 

src/entities/point.rs

@@ -22,6 +22,7 @@ fn to_truck(pt: &Point) -> TruckEntity {
         snap_pts: vec![(snap, SnapHint::Node)],
         tangent_geoms: vec![],
         key_vertices: vec![],
+        fill_tris: vec![],
     }
 }
 

src/entities/polyline.rs

@@ -31,6 +31,7 @@ fn tessellate_polyline(pl: &Polyline) -> TruckEntity {
         snap_pts: vec![],
         tangent_geoms: vec![],
         key_vertices: key_verts,
+        fill_tris: vec![],
     }
 }
 
@@ -127,6 +128,7 @@ fn tessellate_polyline2d(pl: &Polyline2D) -> TruckEntity {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         };
     }
 
@@ -204,7 +206,7 @@ fn tessellate_polyline2d(pl: &Polyline2D) -> TruckEntity {
                 if i + 1 < kv.len() { pts.push([f32::NAN; 3]); }
             }
         }
-        return TruckEntity { object: TruckObject::Lines(pts), snap_pts: vec![], tangent_geoms: tgs, key_vertices: kv };
+        return TruckEntity { object: TruckObject::Lines(pts), snap_pts: vec![], tangent_geoms: tgs, key_vertices: kv, fill_tris: vec![] };
     }
 
     for i in 0..seg_count {
@@ -271,6 +273,7 @@ fn tessellate_polyline2d(pl: &Polyline2D) -> TruckEntity {
         snap_pts: vec![],
         tangent_geoms: tangents,
         key_vertices: key_verts,
+        fill_tris: vec![],
     }
 }
 
@@ -397,6 +400,7 @@ fn tessellate_polyline3d(pl: &Polyline3D) -> TruckEntity {
         snap_pts: vec![],
         tangent_geoms: vec![],
         key_vertices: key_verts,
+        fill_tris: vec![],
     }
 }
 

src/entities/raster_image.rs

@@ -129,6 +129,7 @@ impl TruckConvertible for RasterImage {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: corners.to_vec(),
+            fill_tris: vec![],
         })
     }
 }
@@ -289,6 +290,7 @@ impl TruckConvertible for Wipeout {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: corners.to_vec(),
+            fill_tris: vec![],
         })
     }
 }

src/entities/ray.rs

@@ -34,6 +34,7 @@ impl TruckConvertible for Ray {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![start],
+            fill_tris: vec![],
         })
     }
 }
@@ -165,6 +166,7 @@ impl TruckConvertible for XLine {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![[bp.x as f32, bp.y as f32, bp.z as f32]],
+            fill_tris: vec![],
         })
     }
 }

src/entities/shape.rs

@@ -47,6 +47,7 @@ impl TruckConvertible for Shape {
             snap_pts: vec![(snap_pt, SnapHint::Insertion)],
             tangent_geoms: vec![],
             key_vertices: vec![[ox, oy, oz]],
+            fill_tris: vec![],
         })
     }
 }

src/entities/solid.rs

@@ -47,6 +47,7 @@ impl TruckConvertible for Solid {
             snap_pts: snap,
             tangent_geoms: vec![],
             key_vertices: vec![p0, p1, p2, p3],
+            fill_tris: vec![],
         })
     }
 }

src/entities/spline.rs

@@ -19,6 +19,7 @@ fn to_truck(spl: &Spline) -> TruckEntity {
             snap_pts: vec![],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         };
     }
 
@@ -92,6 +93,7 @@ fn to_truck(spl: &Spline) -> TruckEntity {
         snap_pts: vec![],
         tangent_geoms: vec![],
         key_vertices,
+        fill_tris: vec![],
     }
 }
 

src/entities/table.rs

@@ -137,6 +137,7 @@ impl TruckConvertible for Table {
             snap_pts: vec![(origin, SnapHint::Insertion)],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         })
     }
 }

src/entities/text.rs

@@ -125,6 +125,7 @@ fn to_truck(t: &Text, document: &acadrust::CadDocument) -> TruckEntity {
         snap_pts: vec![(snap_pt, SnapHint::Insertion)],
         tangent_geoms: vec![],
         key_vertices: vec![],
+        fill_tris: vec![],
     }
 }
 

src/entities/tolerance.rs

@@ -236,6 +236,7 @@ impl TruckConvertible for Tolerance {
             snap_pts: vec![(snap_pt, SnapHint::Insertion)],
             tangent_geoms: vec![],
             key_vertices: vec![],
+            fill_tris: vec![],
         })
     }
 }

src/entities/underlay.rs

@@ -56,6 +56,7 @@ impl TruckConvertible for Underlay {
                 snap_pts: vec![(Vec3::from(origin), SnapHint::Node)],
                 tangent_geoms: vec![],
                 key_vertices: key,
+                fill_tris: vec![],
             })
         } else {
             // No clip boundary: draw a cross at insertion point.
@@ -65,6 +66,7 @@ impl TruckConvertible for Underlay {
                 snap_pts: vec![(Vec3::from(origin), SnapHint::Node)],
                 tangent_geoms: vec![],
                 key_vertices: vec![origin],
+                fill_tris: vec![],
             })
         }
     }

src/modules/annotate/aligned_dim.rs

@@ -104,6 +104,7 @@ impl CadCommand for AlignedDimensionCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }
@@ -140,5 +141,6 @@ fn preview_aligned(p1: Vec3, p2: Vec3, dim_pt: Vec3) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }

src/modules/annotate/angular_dim.rs

@@ -127,6 +127,7 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }
 

src/modules/annotate/diameter_dim.rs

@@ -103,5 +103,6 @@ fn preview_line(a: Vec3, b: Vec3) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }

src/modules/annotate/dim_baseline.rs

@@ -145,6 +145,7 @@ impl CadCommand for DimBaselineCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/annotate/dim_continue.rs

@@ -142,6 +142,7 @@ impl CadCommand for DimContinueCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/annotate/dimjogline.rs

@@ -96,6 +96,7 @@ impl CadCommand for DimJogLineCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/annotate/dimtedit.rs

@@ -104,6 +104,7 @@ impl CadCommand for DimTeditCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 

src/modules/annotate/leader_cmd.rs

@@ -204,6 +204,7 @@ fn preview_wire(pts: &[Vec3]) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }
 

src/modules/annotate/linear_dim.rs

@@ -115,6 +115,7 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }
 

src/modules/annotate/mleader_cmd.rs

@@ -157,6 +157,7 @@ fn preview_wire(pts: &[Vec3]) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }
 

src/modules/annotate/mleader_edit.rs

@@ -368,6 +368,7 @@ fn preview_wire(pts: &[Vec3]) -> WireModel {
         aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }
 

src/modules/annotate/qdim.rs

@@ -101,6 +101,7 @@ impl CadCommand for QdimCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/annotate/radius_dim.rs

@@ -114,5 +114,6 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }

src/modules/annotate/table_cmd.rs

@@ -147,6 +147,7 @@ impl CadCommand for TableCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
             })
         } else {
             None

src/modules/annotate/tolerance_cmd.rs

@@ -100,6 +100,7 @@ impl CadCommand for ToleranceCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/draw/attdef.rs

@@ -136,6 +136,7 @@ impl CadCommand for AttdefCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/draw/ellipse.rs

@@ -529,5 +529,6 @@ fn line_wire(from: Vec3, to: Vec3) -> WireModel {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }

src/modules/home/draw/line.rs

@@ -90,6 +90,7 @@ impl CadCommand for LineCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/draw/mline.rs

@@ -115,6 +115,7 @@ impl CadCommand for MlineCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/draw/raster_image.rs

@@ -114,6 +114,7 @@ impl CadCommand for ImageCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/draw/ray.rs

@@ -88,6 +88,7 @@ impl CadCommand for RayCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }
@@ -168,6 +169,7 @@ impl CadCommand for XLineCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/draw/revcloud.rs

@@ -85,6 +85,7 @@ impl CadCommand for RevCloudCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/draw/wipeout.rs

@@ -121,6 +121,7 @@ impl CadCommand for WipeoutCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                 })
             }
             WipeoutMode::Polygonal => {
@@ -144,6 +145,7 @@ impl CadCommand for WipeoutCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                 })
             }
         }

src/modules/home/inquiry/area.rs

@@ -78,6 +78,7 @@ impl CadCommand for AreaCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/inquiry/dist.rs

@@ -73,6 +73,7 @@ impl CadCommand for DistCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/home/modify/stretch.rs

@@ -136,6 +136,7 @@ impl CadCommand for StretchCommand {
                     aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                 })
             }
             _ => None,

src/modules/layout/mview.rs

@@ -100,6 +100,7 @@ impl CadCommand for MviewCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/view/plot_window.rs

@@ -65,6 +65,7 @@ impl CadCommand for PlotWindowCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/modules/view/zoom_window.rs

@@ -71,6 +71,7 @@ impl CadCommand for ZoomWindowCommand {
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
     }
 }

src/scene/acad_to_truck.rs

@@ -33,6 +33,9 @@ pub struct TruckEntity {
     pub snap_pts: Vec<(Vec3, SnapHint)>,
     pub tangent_geoms: Vec<TangentGeom>,
     pub key_vertices: Vec<[f32; 3]>,
+    /// Pre-triangulated fill geometry: flat list of [f32;3] vertices, 3 per triangle.
+    /// Non-empty for mesh-like entities (PolyfaceMesh, PolygonMesh) that need solid fill.
+    pub fill_tris: Vec<[f32; 3]>,
 }
 
 pub fn convert(entity: &EntityType, document: &CadDocument) -> Option<TruckEntity> {

src/scene/complex_lt.rs

@@ -204,6 +204,7 @@ pub fn apply_along(
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         })
         .collect()
 }

src/scene/mod.rs

@@ -3505,6 +3505,7 @@ fn tessellate_entity(
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         });
         return wires;
     }

src/scene/pipeline/face3d_gpu.rs

@@ -52,16 +52,17 @@ pub struct Face3DGpu {
 }
 
 impl Face3DGpu {
-    /// Build a batched GPU buffer from Face3D wire models.
+    /// Build a batched GPU buffer from Face3D wire models and mesh fill_tris.
     ///
-    /// Each WireModel's `key_vertices` holds the 4 corners in local space
+    /// - `face3d_wires`: Face3D entities — `key_vertices` holds 4 quad corners;
-    /// (world_offset already applied by tessellate.rs).  Two triangles are
+    ///   emits 2 triangles per face.
-    /// emitted per face: (p0,p1,p2) and (p0,p2,p3).
+    /// - `all_wires`: all entity wires — `fill_tris` holds pre-triangulated
-    pub fn from_wires(device: &wgpu::Device, wires: &[WireModel]) -> Self {
+    ///   fill data for PolyfaceMesh / PolygonMesh.
-        let mut vertices: Vec<Face3DVertex> = Vec::with_capacity(wires.len() * 6);
+    pub fn from_wires(device: &wgpu::Device, face3d_wires: &[WireModel], all_wires: &[WireModel]) -> Self {
+        let mut vertices: Vec<Face3DVertex> = Vec::with_capacity(face3d_wires.len() * 6);
 
-        for wire in wires {
+        // Face3D quads (4 key_vertices → 2 triangles).
-            // key_vertices has exactly 4 entries for Face3D (p0..p3).
+        for wire in face3d_wires {
             if wire.key_vertices.len() < 4 {
                 continue;
             }
@@ -69,17 +70,26 @@ impl Face3DGpu {
             let fill_color = [r * 0.45, g * 0.45, b * 0.45, a];
             let p = &wire.key_vertices;
             let v = |i: usize| Face3DVertex { position: p[i], color: fill_color };
-
-            // Triangle 1: p0, p1, p2
             vertices.push(v(0));
             vertices.push(v(1));
             vertices.push(v(2));
-            // Triangle 2: p0, p2, p3
             vertices.push(v(0));
             vertices.push(v(2));
             vertices.push(v(3));
         }
 
+        // PolyfaceMesh / PolygonMesh pre-triangulated fills.
+        for wire in all_wires {
+            if wire.fill_tris.is_empty() {
+                continue;
+            }
+            let [r, g, b, a] = wire.color;
+            let fill_color = [r * 0.45, g * 0.45, b * 0.45, a];
+            for &position in &wire.fill_tris {
+                vertices.push(Face3DVertex { position, color: fill_color });
+            }
+        }
+
         let vertex_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
             label: Some("face3d.vbuf"),
             contents: bytemuck::cast_slice(&vertices),

src/scene/pipeline/mod.rs

@@ -637,13 +637,15 @@ impl Pipeline {
     /// Upload all 3DFACE entities as two batched GPU objects:
     /// - `gpu_face3d_fill`: filled triangles (1 buffer, 1 draw call)
     /// - `gpu_face3d_edges`: merged edge wires (1 buffer, 1 draw call)
-    pub fn upload_face3d(&mut self, device: &wgpu::Device, face3d_wires: &[WireModel]) {
+    pub fn upload_face3d(&mut self, device: &wgpu::Device, face3d_wires: &[WireModel], all_wires: &[WireModel]) {
-        if face3d_wires.is_empty() {
+        let has_fills = !face3d_wires.is_empty()
+            || all_wires.iter().any(|w| !w.fill_tris.is_empty());
+        if !has_fills {
             self.gpu_face3d_fill = None;
             self.gpu_face3d_edges = vec![];
             return;
         }
-        self.gpu_face3d_fill = Some(Face3DGpu::from_wires(device, face3d_wires));
+        self.gpu_face3d_fill = Some(Face3DGpu::from_wires(device, face3d_wires, all_wires));
         self.gpu_face3d_edges = WireGpu::from_batch(device, face3d_wires);
     }
 

src/scene/render.rs

@@ -128,7 +128,7 @@ impl shader::Primitive for Primitive {
             pipeline.upload_images(device, queue, &self.images[..]);
             pipeline.upload_meshes(device, &self.meshes[..]);
             pipeline.upload_wires(device, &self.wires[..]);
-            pipeline.upload_face3d(device, &self.face3d_wires[..]);
+            pipeline.upload_face3d(device, &self.face3d_wires[..], &self.wires[..]);
             pipeline.cached_epoch = self.geometry_epoch;
         }
         pipeline.compute_wire_scissors(self.uniforms.view_proj, clip_size.width, clip_size.height);

src/scene/tessellate.rs

@@ -147,6 +147,7 @@ pub fn tessellate(
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                 };
             }
 
@@ -177,6 +178,7 @@ pub fn tessellate(
                             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                         };
                     }
                     _ => {}
@@ -205,6 +207,7 @@ pub fn tessellate(
                         aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                     };
                 }
             }
@@ -231,6 +234,7 @@ pub fn tessellate(
                         aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
                     };
                 }
             }
@@ -248,6 +252,9 @@ pub fn tessellate(
                 let key_vertices: Vec<[f32; 3]> = te.key_vertices.into_iter()
                     .map(|[x, y, z]| [x - ox as f32, y - oy as f32, z - oz as f32])
                     .collect();
+                let fill_tris: Vec<[f32; 3]> = te.fill_tris.into_iter()
+                    .map(|[x, y, z]| [x - ox as f32, y - oy as f32, z - oz as f32])
+                    .collect();
                 return WireModel {
                     name,
                     points: local_pts,
@@ -262,7 +269,8 @@ pub fn tessellate(
                     key_vertices,
                     aabb: WireModel::UNBOUNDED_AABB,
                     plinegen: true,
-            vp_scissor: None,
+                    vp_scissor: None,
+                    fill_tris,
                 };
             }
 
@@ -291,6 +299,7 @@ pub fn tessellate(
                     plinegen: false,
             vp_scissor: None,
                     aabb: WireModel::UNBOUNDED_AABB,
+                    fill_tris: vec![],
                 };
             }
 
@@ -339,6 +348,7 @@ pub fn tessellate(
         aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }
 }
 
@@ -397,6 +407,7 @@ pub fn tessellate_dimension(
         aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
     }];
 
     if let Some(text) = dimension_text_entity(dim) {
@@ -454,6 +465,7 @@ fn tessellate_leader_single(
             aabb: WireModel::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         };
     }
 
@@ -508,6 +520,7 @@ fn tessellate_leader_single(
         aabb: WireModel::UNBOUNDED_AABB,
         plinegen: true,
         vp_scissor: None,
+        fill_tris: vec![],
     }
 }
 
@@ -637,6 +650,7 @@ fn tessellate_multileader_single(
         aabb: WireModel::UNBOUNDED_AABB,
         plinegen: true,
         vp_scissor: None,
+        fill_tris: vec![],
     }
 }
 

src/scene/wire_model.rs

@@ -66,6 +66,9 @@ pub struct WireModel {
     /// Paper-space bounding box [x0, y0, x1, y1] for GPU scissor clipping.
     /// Set only for viewport-projected wires in paper-space layouts.
     pub vp_scissor: Option<[f32; 4]>,
+    /// Pre-triangulated solid fill: flat vertex list, 3 per triangle (world-offset applied).
+    /// Non-empty only for PolyfaceMesh / PolygonMesh entities.
+    pub fill_tris: Vec<[f32; 3]>,
 }
 
 impl WireModel {
@@ -93,6 +96,7 @@ impl WireModel {
             aabb: Self::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: vec![],
         }
     }
 
@@ -194,6 +198,7 @@ impl Default for WireModel {
             aabb: Self::UNBOUNDED_AABB,
             plinegen: true,
             vp_scissor: None,
+            fill_tris: Vec::new(),
         }
     }
 }