fix(camera): prevent near-plane clipping during 3D orbit on wide strokes and flat drawings

src/scene/camera_ops.rs

@@ -9,26 +9,37 @@ fn rendered_wire_bounds(
 ) -> Option<(glam::DVec3, glam::DVec3)> {
     let mut min = glam::DVec3::splat(f64::INFINITY);
     let mut max = glam::DVec3::splat(f64::NEG_INFINITY);
-    let mut include = |point: glam::DVec3| {
-        if point.is_finite() {
-            min = min.min(point);
-            max = max.max(point);
-        }
-    };
+    macro_rules! include_bound {
+        ($p:expr) => {
+            let point: glam::DVec3 = $p;
+            if point.is_finite() {
+                min = min.min(point);
+                max = max.max(point);
+            }
+        };
+    }
 
     for wire in wires {
         let mut has_precise_position = false;
+        let hw = wire.world_width as f64 * 0.5;
+
         for (index, &[x, y, z]) in wire.points.iter().enumerate() {
             let low = wire.points_low.get(index).copied().unwrap_or([0.0; 3]);
-            include(glam::DVec3::new(
+            let p = glam::DVec3::new(
                 x as f64 + low[0] as f64,
                 y as f64 + low[1] as f64,
                 z as f64 + low[2] as f64,
-            ));
+            );
+            if hw > 0.0 {
+                include_bound!(p - glam::DVec3::splat(hw));
+                include_bound!(p + glam::DVec3::splat(hw));
+            } else {
+                include_bound!(p);
+            }
             has_precise_position = true;
         }
         for vertex in &wire.text_verts {
-            include(glam::DVec3::new(
+            include_bound!(glam::DVec3::new(
                 vertex.pos[0] as f64 + vertex.pos_low[0] as f64,
                 vertex.pos[1] as f64 + vertex.pos_low[1] as f64,
                 vertex.pos[2] as f64 + vertex.pos_low[2] as f64,
@@ -36,11 +47,17 @@ fn rendered_wire_bounds(
             has_precise_position = true;
         }
         for &[x, y, z] in &wire.key_vertices {
-            include(glam::DVec3::new(x, y, z));
+            let p = glam::DVec3::new(x, y, z);
+            if hw > 0.0 {
+                include_bound!(p - glam::DVec3::splat(hw));
+                include_bound!(p + glam::DVec3::splat(hw));
+            } else {
+                include_bound!(p);
+            }
             has_precise_position = true;
         }
         for &(point, _) in &wire.snap_pts {
-            include(point);
+            include_bound!(point);
             has_precise_position = true;
         }
 
@@ -51,8 +68,8 @@ fn rendered_wire_bounds(
                 && x0 <= x1
                 && y0 <= y1
             {
-                include(glam::DVec3::new(x0 as f64, y0 as f64, fallback_z));
-                include(glam::DVec3::new(x1 as f64, y1 as f64, fallback_z));
+                include_bound!(glam::DVec3::new(x0 as f64 - hw, y0 as f64 - hw, fallback_z - hw));
+                include_bound!(glam::DVec3::new(x1 as f64 + hw, y1 as f64 + hw, fallback_z + hw));
             }
         }
     }
@@ -1455,12 +1472,18 @@ impl Scene {
                 continue;
             }
             let wire = &wires[c.idx];
+            let hw = (wire.world_width * 0.5) as f32;
             for &[x, y, z] in &wire.points {
                 if !x.is_finite() || !y.is_finite() || !z.is_finite() {
                     continue;
                 }
-                min = min.min(glam::Vec3::new(x, y, z));
-                max = max.max(glam::Vec3::new(x, y, z));
+                if hw > 0.0 {
+                    min = min.min(glam::Vec3::new(x - hw, y - hw, z - hw));
+                    max = max.max(glam::Vec3::new(x + hw, y + hw, z + hw));
+                } else {
+                    min = min.min(glam::Vec3::new(x, y, z));
+                    max = max.max(glam::Vec3::new(x, y, z));
+                }
             }
         }
         // Fold in 3D-solid mesh AABBs (not subject to the wire IQR reject).

src/scene/view/camera.rs

@@ -246,23 +246,16 @@ impl Camera {
     /// A symmetric range gives the bias half the depth buffer of headroom on
     /// each side; ortho permits a negative near.
     fn ortho_depth_range(&self) -> (f32, f32) {
-        // Prefer a drawing-sized, zoom-independent half-range so depth-buffer
-        // precision stays constant as the user zooms. A distance-scaled range
-        // (the `else`) balloons the near/far span when zoomed out — at large
-        // `distance` the f32 depth buffer can no longer separate coincident
-        // solids / meshes / wires, so they flip draw order (issue: meshes drew
-        // in front of solids only when zoomed out).
+        // Generous headroom based on the current screen size so that rotating any
+        // geometry visible on screen in 3D never penetrates the near/far planes.
+        let view_extent = (self.ortho_size() * 3.0).max(10.0);
+
         let r = if let Some((min, max)) = self.model_bounds {
-            // Depth extent along the CURRENT eye direction, recomputed each
-            // frame so orbiting a 3-D drawing never clips it (#473): as the
-            // view tilts off top, the box's width rotates onto the eye axis and
-            // the span grows to match. Same tight, zoom-independent precision as
-            // a fitted scalar, but always oriented to the live view.
-            self.depth_extent_in_view(min, max)
+            self.depth_extent_in_view(min, max).max(view_extent)
         } else if self.depth_half_range > 0.0 {
-            self.depth_half_range
+            self.depth_half_range.max(view_extent)
         } else {
-            (self.distance * 1000.0).max(1.0)
+            (self.distance * 1000.0).max(view_extent).max(10.0)
         };
         (self.distance - r, self.distance + r)
     }
@@ -590,7 +583,11 @@ impl Camera {
             .bounds_in_view(min, max)
             .iter()
             .fold(0.0_f32, |m, c| m.max(c.z.abs()));
-        (depth_r * 1.05).max(1.0)
+        let diag = (max - min).length() as f32;
+        // Generous headroom (1.5x depth extent + 25% of model diagonal + minimum clearance)
+        // so wide strokes, lineweights, camera orbit dynamics, and draw-order depth bias
+        // never penetrate the near clipping plane in orthographic 3D view.
+        (depth_r * 1.5 + diag * 0.25).max(10.0)
     }
 
     /// Fit the camera to `min..max` — pose and depth both.