diff --git a/examples/render_braiding.rs b/examples/render_braiding.rs
index ea1c7ed..a63090c 100644
--- a/examples/render_braiding.rs
+++ b/examples/render_braiding.rs
@@ -2,13 +2,15 @@
 //!
 //! Run with: cargo run --example render_braiding
 //!
-//! Outputs fixtures/half_braid_geometry.json with vertices, wires, surfaces, volumes.
+//! Outputs fixtures/half_braid_geometry.json with VISIBLE elements only.
+//! Visibility follows homotopy.io's rule: a point at geom_dim d is visible
+//! iff coords[d..] are all singular.
 
 use std::collections::{HashMap, HashSet, VecDeque};
 use std::fs;
 
-use zigzag_engine::diagram::{Diagram, DiagramN};
-use zigzag_engine::explosion::{HeightLabel, Point, Poset};
+use zigzag_engine::diagram::Diagram;
+use zigzag_engine::explosion::{HeightLabel, Point};
 use zigzag_engine::import::load_homotopy_diagram_n;
 
 use serde::Serialize;
@@ -19,7 +21,6 @@ struct Geometry {
     vertices: Vec<Vertex>,
     wires: Vec<Wire>,
     surfaces: Vec<Surface>,
-    volumes: Vec<Volume>,
 }
 
 #[derive(Serialize)]
@@ -27,6 +28,7 @@ struct Metadata {
     source: String,
     dimension: usize,
     total_points: usize,
+    visible_points: usize,
     total_covers: usize,
 }
 
@@ -43,9 +45,9 @@ struct Wire {
     id: usize,
     label: String,
     point: String,
-    coords: [f64; 3],        // The wire's own coordinate (midpoint/waypoint)
-    endpoints: [usize; 2],   // Vertex IDs
-    endpoint_coords: [[f64; 3]; 2],  // For convenience in renderer
+    coords: [f64; 3],
+    endpoints: [usize; 2],
+    endpoint_coords: [[f64; 3]; 2],
 }
 
 #[derive(Serialize)]
@@ -54,15 +56,7 @@ struct Surface {
     label: String,
     point: String,
     coords: [f64; 3],
-    boundary_wires: Vec<usize>,  // Wire IDs on boundary
-}
-
-#[derive(Serialize)]
-struct Volume {
-    id: usize,
-    label: String,
-    point: String,
-    coords: [f64; 3],
+    boundary_wires: Vec<usize>,
 }
 
 /// Format a point as a string like "s0,s1,r0"
@@ -76,15 +70,37 @@ fn format_point(p: &Point) -> String {
         .join(",")
 }
 
-/// Compute linear coordinates from height labels
-fn linear_coords(p: &Point) -> [f64; 3] {
-    let coords: Vec<f64> = p.0.iter().map(|h| h.to_linear_index() as f64).collect();
-    // Pad to 3D if needed
-    [
-        coords.get(0).copied().unwrap_or(0.0),
-        coords.get(1).copied().unwrap_or(0.0),
-        coords.get(2).copied().unwrap_or(0.0),
-    ]
+/// Compute layout coordinates for rendering.
+///
+/// For half_braid visible elements:
+/// - coord[0] (depth/strand): r0→-1, r1→0, r2→1 for wires; s0→-0.5, s1→0.5 for vertices
+/// - coord[1] (height): r0→-1, s0→0, r1→1 for layout y
+/// - coord[2] (time): s0→0 for visible elements (all at crossing time)
+///
+/// Output: [x, y, z] where:
+/// - x = time (all 0 for visible crossing slice)
+/// - y = height
+/// - z = depth (spread wires/vertices along this axis)
+fn layout_coords(p: &Point) -> [f64; 3] {
+    // For the visible crossing slice, all elements have coord[2] = s0 (time = singular)
+    // So x (time) = 0 for all visible elements
+
+    // z = depth axis (coord[0])
+    let z = match &p.0[0] {
+        HeightLabel::Regular(j) => (*j as f64) - 1.0,  // r0→-1, r1→0, r2→1
+        HeightLabel::Singular(j) => (*j as f64) - 0.5, // s0→-0.5, s1→0.5
+    };
+
+    // y = height axis (coord[1])
+    let y = match &p.0[1] {
+        HeightLabel::Regular(j) => (*j as f64) - 1.0,  // r0→-1, r1→1
+        HeightLabel::Singular(j) => *j as f64,         // s0→0
+    };
+
+    // x = time axis (coord[2]) - all visible elements are at s0
+    let x = 0.0;
+
+    [x, y, z]
 }
 
 /// Count singular labels in a point
@@ -111,14 +127,25 @@ fn main() {
     eprintln!("Loaded half_braid.json: dim={}, {} points, {} covers",
         n, pts.len(), pts.covers().len());
 
-    // Group points by geometric dimension
+    // Filter to VISIBLE points only
+    let visible_indices: Vec<usize> = pts.elements()
+        .iter()
+        .enumerate()
+        .filter(|(_, point)| point.is_visible(n))
+        .map(|(idx, _)| idx)
+        .collect();
+
+    eprintln!("Visible points: {}", visible_indices.len());
+
+    // Group visible points by geometric dimension
     let mut by_geom_dim: HashMap<usize, Vec<usize>> = HashMap::new();
-    for (idx, point) in pts.elements().iter().enumerate() {
+    for &idx in &visible_indices {
+        let point = &pts.elements()[idx];
         let gd = geom_dim(point, n);
         by_geom_dim.entry(gd).or_default().push(idx);
     }
 
-    // Build adjacency for reachability
+    // Build adjacency for reachability (on full poset)
     let mut successors: Vec<Vec<usize>> = vec![vec![]; pts.len()];
     let mut predecessors: Vec<Vec<usize>> = vec![vec![]; pts.len()];
     for &(lower, upper) in pts.covers() {
@@ -126,7 +153,7 @@ fn main() {
         predecessors[upper].push(lower);
     }
 
-    // Helper: find all transitively reachable points (for wire→vertex connections)
+    // Helper: find all transitively reachable points
     let reachable_from = |start: usize, adj: &[Vec<usize>]| -> HashSet<usize> {
         let mut visited = HashSet::new();
         let mut queue = VecDeque::new();
@@ -142,12 +169,13 @@ fn main() {
         visited
     };
 
-    // Get vertex indices
+    // Get visible vertex indices
     let vertex_indices = by_geom_dim.get(&0).map(|v| v.as_slice()).unwrap_or(&[]);
     let vertex_set: HashSet<usize> = vertex_indices.iter().copied().collect();
 
-    // Get wire indices
+    // Get visible wire indices
     let wire_indices = by_geom_dim.get(&1).map(|v| v.as_slice()).unwrap_or(&[]);
+    let wire_set: HashSet<usize> = wire_indices.iter().copied().collect();
 
     // Build vertices
     let mut vertices: Vec<Vertex> = Vec::new();
@@ -157,7 +185,7 @@ fn main() {
             id: idx,
             label: format!("vertex_{}", i),
             point: format_point(point),
-            coords: linear_coords(point),
+            coords: layout_coords(point),
         });
     }
 
@@ -166,8 +194,7 @@ fn main() {
     for (i, &idx) in wire_indices.iter().enumerate() {
         let point = &pts.elements()[idx];
 
-        // Find connected vertices via TRANSITIVE reachability
-        // A wire (strand) spans between vertices even if the poset path has intermediate points
+        // Find connected VISIBLE vertices via transitive reachability
         let reachable_up = reachable_from(idx, &successors);
         let reachable_down = reachable_from(idx, &predecessors);
 
@@ -179,43 +206,38 @@ fn main() {
         connected.sort();
         connected.dedup();
 
-        // Default to first two vertices if we don't have exactly 2
         let endpoints = if connected.len() >= 2 {
             [connected[0], connected[1]]
         } else if connected.len() == 1 {
-            // Wire connects to only one vertex - use same vertex twice
-            // (This represents a loop or boundary wire)
             [connected[0], connected[0]]
         } else {
-            // No connected vertices found - use first two vertices as fallback
             [vertex_indices[0], vertex_indices.get(1).copied().unwrap_or(vertex_indices[0])]
         };
 
         let endpoint_coords = [
-            linear_coords(&pts.elements()[endpoints[0]]),
-            linear_coords(&pts.elements()[endpoints[1]]),
+            layout_coords(&pts.elements()[endpoints[0]]),
+            layout_coords(&pts.elements()[endpoints[1]]),
         ];
 
         wires.push(Wire {
             id: idx,
             label: format!("wire_{}", i),
             point: format_point(point),
-            coords: linear_coords(point),
+            coords: layout_coords(point),
             endpoints,
             endpoint_coords,
         });
     }
 
-    // Build surfaces (geom_dim=2)
+    // Build visible surfaces (geom_dim=2)
     let surface_indices = by_geom_dim.get(&2).map(|v| v.as_slice()).unwrap_or(&[]);
-    let wire_set: HashSet<usize> = wire_indices.iter().copied().collect();
 
     let mut surfaces: Vec<Surface> = Vec::new();
     for (i, &idx) in surface_indices.iter().enumerate() {
         let point = &pts.elements()[idx];
 
-        // Find boundary wires via DIRECT covering relations only
-        // Surface (geom_dim=2) connects to wires (geom_dim=1) via single covers
+        // Find boundary wires via DIRECT covering relations
+        // Filter to only VISIBLE wires
         let mut boundary_wires: Vec<usize> = successors[idx]
             .iter()
             .chain(predecessors[idx].iter())
@@ -223,42 +245,29 @@ fn main() {
             .copied()
             .collect();
         boundary_wires.sort();
+        boundary_wires.dedup();
 
         surfaces.push(Surface {
             id: idx,
             label: format!("surface_{}", i),
             point: format_point(point),
-            coords: linear_coords(point),
+            coords: layout_coords(point),
             boundary_wires,
         });
     }
 
-    // Build volumes (geom_dim=3)
-    let volume_indices = by_geom_dim.get(&3).map(|v| v.as_slice()).unwrap_or(&[]);
-
-    let mut volumes: Vec<Volume> = Vec::new();
-    for (i, &idx) in volume_indices.iter().enumerate() {
-        let point = &pts.elements()[idx];
-        volumes.push(Volume {
-            id: idx,
-            label: format!("volume_{}", i),
-            point: format_point(point),
-            coords: linear_coords(point),
-        });
-    }
-
-    // Build output
+    // Build output (no volumes - they're not rendered)
     let geometry = Geometry {
         metadata: Metadata {
             source: "half_braid.json".to_string(),
             dimension: n,
             total_points: pts.len(),
+            visible_points: visible_indices.len(),
             total_covers: pts.covers().len(),
         },
         vertices,
         wires,
         surfaces,
-        volumes,
     };
 
     // Output JSON
@@ -268,11 +277,10 @@ fn main() {
     fs::write("fixtures/half_braid_geometry.json", &json_output)
         .expect("Failed to write fixtures/half_braid_geometry.json");
 
-    eprintln!("\nWrote fixtures/half_braid_geometry.json");
+    eprintln!("\nWrote fixtures/half_braid_geometry.json (VISIBLE ONLY)");
     eprintln!("  {} vertices", geometry.vertices.len());
     eprintln!("  {} wires", geometry.wires.len());
     eprintln!("  {} surfaces", geometry.surfaces.len());
-    eprintln!("  {} volumes", geometry.volumes.len());
 
     // Also print to stdout for piping
     println!("{}", json_output);
diff --git a/fixtures/half_braid_geometry.json b/fixtures/half_braid_geometry.json
index ef0b440..23be593 100644
--- a/fixtures/half_braid_geometry.json
+++ b/fixtures/half_braid_geometry.json
@@ -3,6 +3,7 @@
     "source": "half_braid.json",
     "dimension": 3,
     "total_points": 23,
+    "visible_points": 12,
     "total_covers": 35
   },
   "vertices": [
@@ -11,9 +12,9 @@
       "label": "vertex_0",
       "point": "s0,s0,s0",
       "coords": [
-        1.0,
-        1.0,
-        1.0
+        0.0,
+        0.0,
+        -0.5
       ]
     },
     {
@@ -21,125 +22,21 @@
       "label": "vertex_1",
       "point": "s1,s0,s0",
       "coords": [
-        3.0,
-        1.0,
-        1.0
+        0.0,
+        0.0,
+        0.5
       ]
     }
   ],
   "wires": [
-    {
-      "id": 5,
-      "label": "wire_0",
-      "point": "s0,s0,r0",
-      "coords": [
-        1.0,
-        1.0,
-        0.0
-      ],
-      "endpoints": [
-        21,
-        22
-      ],
-      "endpoint_coords": [
-        [
-          1.0,
-          1.0,
-          1.0
-        ],
-        [
-          3.0,
-          1.0,
-          1.0
-        ]
-      ]
-    },
-    {
-      "id": 8,
-      "label": "wire_1",
-      "point": "s0,s1,r0",
-      "coords": [
-        1.0,
-        3.0,
-        0.0
-      ],
-      "endpoints": [
-        21,
-        22
-      ],
-      "endpoint_coords": [
-        [
-          1.0,
-          1.0,
-          1.0
-        ],
-        [
-          3.0,
-          1.0,
-          1.0
-        ]
-      ]
-    },
-    {
-      "id": 14,
-      "label": "wire_2",
-      "point": "s0,s0,r1",
-      "coords": [
-        1.0,
-        1.0,
-        2.0
-      ],
-      "endpoints": [
-        21,
-        21
-      ],
-      "endpoint_coords": [
-        [
-          1.0,
-          1.0,
-          1.0
-        ],
-        [
-          1.0,
-          1.0,
-          1.0
-        ]
-      ]
-    },
-    {
-      "id": 15,
-      "label": "wire_3",
-      "point": "s1,s0,r1",
-      "coords": [
-        3.0,
-        1.0,
-        2.0
-      ],
-      "endpoints": [
-        21,
-        22
-      ],
-      "endpoint_coords": [
-        [
-          1.0,
-          1.0,
-          1.0
-        ],
-        [
-          3.0,
-          1.0,
-          1.0
-        ]
-      ]
-    },
     {
       "id": 18,
-      "label": "wire_4",
+      "label": "wire_0",
       "point": "r0,s0,s0",
       "coords": [
         0.0,
-        1.0,
-        1.0
+        0.0,
+        -1.0
       ],
       "endpoints": [
         21,
@@ -147,25 +44,25 @@
       ],
       "endpoint_coords": [
         [
-          1.0,
-          1.0,
-          1.0
+          0.0,
+          0.0,
+          -0.5
         ],
         [
-          3.0,
-          1.0,
-          1.0
+          0.0,
+          0.0,
+          0.5
         ]
       ]
     },
     {
       "id": 19,
-      "label": "wire_5",
+      "label": "wire_1",
       "point": "r1,s0,s0",
       "coords": [
-        2.0,
-        1.0,
-        1.0
+        0.0,
+        0.0,
+        0.0
       ],
       "endpoints": [
         21,
@@ -173,24 +70,24 @@
       ],
       "endpoint_coords": [
         [
-          1.0,
-          1.0,
-          1.0
+          0.0,
+          0.0,
+          -0.5
         ],
         [
-          3.0,
-          1.0,
-          1.0
+          0.0,
+          0.0,
+          0.5
         ]
       ]
     },
     {
       "id": 20,
-      "label": "wire_6",
+      "label": "wire_2",
       "point": "r2,s0,s0",
       "coords": [
-        4.0,
-        1.0,
+        0.0,
+        0.0,
         1.0
       ],
       "endpoints": [
@@ -199,126 +96,27 @@
       ],
       "endpoint_coords": [
         [
-          1.0,
-          1.0,
-          1.0
+          0.0,
+          0.0,
+          -0.5
         ],
         [
-          3.0,
-          1.0,
-          1.0
+          0.0,
+          0.0,
+          0.5
         ]
       ]
     }
   ],
   "surfaces": [
-    {
-      "id": 3,
-      "label": "surface_0",
-      "point": "r0,s0,r0",
-      "coords": [
-        0.0,
-        1.0,
-        0.0
-      ],
-      "boundary_wires": [
-        5,
-        18
-      ]
-    },
-    {
-      "id": 4,
-      "label": "surface_1",
-      "point": "r1,s0,r0",
-      "coords": [
-        2.0,
-        1.0,
-        0.0
-      ],
-      "boundary_wires": [
-        5,
-        19
-      ]
-    },
-    {
-      "id": 6,
-      "label": "surface_2",
-      "point": "r0,s1,r0",
-      "coords": [
-        0.0,
-        3.0,
-        0.0
-      ],
-      "boundary_wires": [
-        8,
-        18
-      ]
-    },
-    {
-      "id": 7,
-      "label": "surface_3",
-      "point": "r1,s1,r0",
-      "coords": [
-        2.0,
-        3.0,
-        0.0
-      ],
-      "boundary_wires": [
-        8,
-        19
-      ]
-    },
-    {
-      "id": 11,
-      "label": "surface_4",
-      "point": "r0,s0,r1",
-      "coords": [
-        0.0,
-        1.0,
-        2.0
-      ],
-      "boundary_wires": [
-        14,
-        18
-      ]
-    },
-    {
-      "id": 12,
-      "label": "surface_5",
-      "point": "r1,s0,r1",
-      "coords": [
-        2.0,
-        1.0,
-        2.0
-      ],
-      "boundary_wires": [
-        14,
-        15,
-        19
-      ]
-    },
-    {
-      "id": 13,
-      "label": "surface_6",
-      "point": "r2,s0,r1",
-      "coords": [
-        4.0,
-        1.0,
-        2.0
-      ],
-      "boundary_wires": [
-        15,
-        20
-      ]
-    },
     {
       "id": 16,
-      "label": "surface_7",
+      "label": "surface_0",
       "point": "r0,r0,s0",
       "coords": [
         0.0,
-        0.0,
-        1.0
+        -1.0,
+        -1.0
       ],
       "boundary_wires": [
         18
@@ -326,68 +124,16 @@
     },
     {
       "id": 17,
-      "label": "surface_8",
+      "label": "surface_1",
       "point": "r0,r1,s0",
       "coords": [
         0.0,
-        2.0,
-        1.0
+        0.0,
+        -1.0
       ],
       "boundary_wires": [
         18
       ]
     }
-  ],
-  "volumes": [
-    {
-      "id": 0,
-      "label": "volume_0",
-      "point": "r0,r0,r0",
-      "coords": [
-        0.0,
-        0.0,
-        0.0
-      ]
-    },
-    {
-      "id": 1,
-      "label": "volume_1",
-      "point": "r0,r1,r0",
-      "coords": [
-        0.0,
-        2.0,
-        0.0
-      ]
-    },
-    {
-      "id": 2,
-      "label": "volume_2",
-      "point": "r0,r2,r0",
-      "coords": [
-        0.0,
-        4.0,
-        0.0
-      ]
-    },
-    {
-      "id": 9,
-      "label": "volume_3",
-      "point": "r0,r0,r1",
-      "coords": [
-        0.0,
-        0.0,
-        2.0
-      ]
-    },
-    {
-      "id": 10,
-      "label": "volume_4",
-      "point": "r0,r1,r1",
-      "coords": [
-        0.0,
-        2.0,
-        2.0
-      ]
-    }
   ]
 }
\ No newline at end of file
diff --git a/src/explosion.rs b/src/explosion.rs
index 3c15abc..063210c 100644
--- a/src/explosion.rs
+++ b/src/explosion.rs
@@ -120,6 +120,19 @@ impl Point {
         labels.push(label);
         Self(labels)
     }
+
+    /// Check if this point is visible for rendering.
+    ///
+    /// A point at geometric dimension d is visible iff coords[d..] are all singular.
+    /// This matches homotopy.io's visibility filter (mesh.rs:111-115).
+    ///
+    /// Geometric dimension = total_dim - singular_count, where singular_count
+    /// is the number of singular labels in the point.
+    pub fn is_visible(&self, total_dim: usize) -> bool {
+        let singular_count = self.0.iter().filter(|h| h.is_singular()).count();
+        let geom_dim = total_dim - singular_count;
+        self.0.iter().skip(geom_dim).all(|h| h.is_singular())
+    }
 }
 
 /// A poset: a set with a partial order.
diff --git a/web/zigzag-renderer.jsx b/web/zigzag-renderer.jsx
index c7fb2ae..6b9bf74 100644
--- a/web/zigzag-renderer.jsx
+++ b/web/zigzag-renderer.jsx
@@ -1,57 +1,38 @@
 // Three.js renderer for zigzag-engine half_braid geometry
-// Renders vertices, wires (elastic curves), and surfaces from explosion poset
+// Renders VISIBLE elements only from explosion poset
+// Visibility: point at geom_dim d is visible iff coords[d..] are all singular
 
 const GEOMETRY_DATA = {
   "metadata": {
     "source": "half_braid.json",
     "dimension": 3,
     "total_points": 23,
+    "visible_points": 7,
     "total_covers": 35
   },
   "vertices": [
-    { "id": 21, "label": "vertex_0", "point": "s0,s0,s0", "coords": [1.0, 1.0, 1.0] },
-    { "id": 22, "label": "vertex_1", "point": "s1,s0,s0", "coords": [3.0, 1.0, 1.0] }
+    { "id": 21, "label": "vertex_0", "point": "s0,s0,s0", "coords": [0.0, 0.0, -0.5] },
+    { "id": 22, "label": "vertex_1", "point": "s1,s0,s0", "coords": [0.0, 0.0, 0.5] }
   ],
   "wires": [
-    { "id": 5, "label": "wire_0", "point": "s0,s0,r0", "coords": [1.0, 1.0, 0.0],
-      "endpoints": [21, 22], "endpoint_coords": [[1.0, 1.0, 1.0], [3.0, 1.0, 1.0]] },
-    { "id": 8, "label": "wire_1", "point": "s0,s1,r0", "coords": [1.0, 3.0, 0.0],
-      "endpoints": [21, 22], "endpoint_coords": [[1.0, 1.0, 1.0], [3.0, 1.0, 1.0]] },
-    { "id": 14, "label": "wire_2", "point": "s0,s0,r1", "coords": [1.0, 1.0, 2.0],
-      "endpoints": [21, 21], "endpoint_coords": [[1.0, 1.0, 1.0], [1.0, 1.0, 1.0]] },
-    { "id": 15, "label": "wire_3", "point": "s1,s0,r1", "coords": [3.0, 1.0, 2.0],
-      "endpoints": [21, 22], "endpoint_coords": [[1.0, 1.0, 1.0], [3.0, 1.0, 1.0]] },
-    { "id": 18, "label": "wire_4", "point": "r0,s0,s0", "coords": [0.0, 1.0, 1.0],
-      "endpoints": [21, 22], "endpoint_coords": [[1.0, 1.0, 1.0], [3.0, 1.0, 1.0]] },
-    { "id": 19, "label": "wire_5", "point": "r1,s0,s0", "coords": [2.0, 1.0, 1.0],
-      "endpoints": [21, 22], "endpoint_coords": [[1.0, 1.0, 1.0], [3.0, 1.0, 1.0]] },
-    { "id": 20, "label": "wire_6", "point": "r2,s0,s0", "coords": [4.0, 1.0, 1.0],
-      "endpoints": [21, 22], "endpoint_coords": [[1.0, 1.0, 1.0], [3.0, 1.0, 1.0]] }
+    { "id": 18, "label": "wire_0", "point": "r0,s0,s0", "coords": [0.0, 0.0, -1.0],
+      "endpoints": [21, 22], "endpoint_coords": [[0.0, 0.0, -0.5], [0.0, 0.0, 0.5]] },
+    { "id": 19, "label": "wire_1", "point": "r1,s0,s0", "coords": [0.0, 0.0, 0.0],
+      "endpoints": [21, 22], "endpoint_coords": [[0.0, 0.0, -0.5], [0.0, 0.0, 0.5]] },
+    { "id": 20, "label": "wire_2", "point": "r2,s0,s0", "coords": [0.0, 0.0, 1.0],
+      "endpoints": [21, 22], "endpoint_coords": [[0.0, 0.0, -0.5], [0.0, 0.0, 0.5]] }
   ],
   "surfaces": [
-    { "id": 3, "label": "surface_0", "point": "r0,s0,r0", "coords": [0.0, 1.0, 0.0], "boundary_wires": [5, 18] },
-    { "id": 4, "label": "surface_1", "point": "r1,s0,r0", "coords": [2.0, 1.0, 0.0], "boundary_wires": [5, 19] },
-    { "id": 6, "label": "surface_2", "point": "r0,s1,r0", "coords": [0.0, 3.0, 0.0], "boundary_wires": [8, 18] },
-    { "id": 7, "label": "surface_3", "point": "r1,s1,r0", "coords": [2.0, 3.0, 0.0], "boundary_wires": [8, 19] },
-    { "id": 11, "label": "surface_4", "point": "r0,s0,r1", "coords": [0.0, 1.0, 2.0], "boundary_wires": [14, 18] },
-    { "id": 12, "label": "surface_5", "point": "r1,s0,r1", "coords": [2.0, 1.0, 2.0], "boundary_wires": [14, 15, 19] },
-    { "id": 13, "label": "surface_6", "point": "r2,s0,r1", "coords": [4.0, 1.0, 2.0], "boundary_wires": [15, 20] },
-    { "id": 16, "label": "surface_7", "point": "r0,r0,s0", "coords": [0.0, 0.0, 1.0], "boundary_wires": [18] },
-    { "id": 17, "label": "surface_8", "point": "r0,r1,s0", "coords": [0.0, 2.0, 1.0], "boundary_wires": [18] }
-  ],
-  "volumes": [
-    { "id": 0, "label": "volume_0", "point": "r0,r0,r0", "coords": [0.0, 0.0, 0.0] },
-    { "id": 1, "label": "volume_1", "point": "r0,r1,r0", "coords": [0.0, 2.0, 0.0] },
-    { "id": 2, "label": "volume_2", "point": "r0,r2,r0", "coords": [0.0, 4.0, 0.0] },
-    { "id": 9, "label": "volume_3", "point": "r0,r0,r1", "coords": [0.0, 0.0, 2.0] },
-    { "id": 10, "label": "volume_4", "point": "r0,r1,r1", "coords": [0.0, 2.0, 2.0] }
+    { "id": 16, "label": "surface_0", "point": "r0,r0,s0", "coords": [0.0, -1.0, -1.0], "boundary_wires": [18] },
+    { "id": 17, "label": "surface_1", "point": "r0,r1,s0", "coords": [0.0, 0.0, -1.0], "boundary_wires": [18] }
   ]
 };
 
-// Coordinate mapping: coord[0]→z, coord[1]→y, coord[2]→x, scale 1.2
-const SCALE = 1.2;
+// Coordinate mapping: coords are already [x, y, z] layout coordinates
+// Scale for better visualization
+const SCALE = 2.0;
 function mapCoords(coords) {
-  return [coords[2] * SCALE, coords[1] * SCALE, coords[0] * SCALE];
+  return [coords[0] * SCALE, coords[1] * SCALE, coords[2] * SCALE];
 }
 
 // Wire colors by group