Sprint 4 — Full bridge scene (Girder×5 + DeckSlab + Bearing×10 + Abutment×2)

viewer/bridge_scene.rs: BridgeScene compositor
- 5× PSC-I Girder (2500mm c/c)
- DeckSlab (12000mm, 220mm thick, top of girders)
- 10× Elastomeric Bearing (5 per abutment end)
- 2× ReverseT Abutment (start & end)
- sweep::merge_meshes로 단일 메시 합성
- scene_extents()로 카메라 자동 배치

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cimery/crates/viewer/src/bridge_scene.rs

@@ -0,0 +1,139 @@
+//! Full bridge scene compositor — Sprint 4.
+//!
+//! Builds a single merged mesh for a simple 40 m single-span PSC-I girder bridge:
+//! - 5 × PSC-I Girder (2500 mm c/c)
+//! - 1 × Deck Slab (12000 mm wide)
+//! - 10 × Elastomeric Bearing (5 per abutment)
+//! - 2 × Abutment (start & end)
+//!
+//! Positions are in the same coordinate space as the girder mesh:
+//!   X = transverse (right = +), Y = vertical (up = +), Z = along span.
+
+use cimery_core::{AbutmentType, BearingType, MaterialGrade, SectionType};
+use cimery_ir::{
+    AbutmentIR, BearingIR, DeckSlabIR, FeatureId, GirderIR,
+    PscISectionParams, SectionParams, WingWallIR,
+};
+use cimery_kernel::{GeomKernel, KernelError, Mesh};
+
+// ─── Helpers ─────────────────────────────────────────────────────────────────
+
+fn translate(mut mesh: Mesh, dx: f32, dy: f32, dz: f32) -> Mesh {
+    for v in &mut mesh.vertices {
+        v[0] += dx;
+        v[1] += dy;
+        v[2] += dz;
+    }
+    mesh
+}
+
+fn merge(meshes: Vec<Mesh>) -> Mesh {
+    cimery_kernel::sweep::merge_meshes(meshes)
+}
+
+// ─── Scene builder ────────────────────────────────────────────────────────────
+
+/// Build a complete bridge scene mesh using the provided kernel.
+pub fn build_bridge_scene<K: GeomKernel>(kernel: &K) -> Result<Mesh, KernelError> {
+    const SPAN_M:       f64 = 40.0;
+    const SPAN_MM:      f32 = 40_000.0;
+    const N_GIRDERS:    usize = 5;
+    const SPACING:      f32 = 2_500.0;   // mm c/c
+    const GIRDER_H:     f32 = 1_800.0;   // mm
+    const BEARING_H:    f32 = 60.0;      // mm
+
+    let mut parts: Vec<Mesh> = Vec::new();
+
+    // ── Girders ────────────────────────────────────────────────────────────────
+    for i in 0..N_GIRDERS {
+        let x = (i as f32 - (N_GIRDERS as f32 - 1.0) * 0.5) * SPACING;
+        let ir = GirderIR {
+            id:                    FeatureId::new(),
+            station_start:         0.0,
+            station_end:           SPAN_M,
+            offset_from_alignment: x as f64,
+            section_type:          SectionType::PscI,
+            section: SectionParams::PscI(PscISectionParams::kds_standard()),
+            count:    1,
+            spacing:  0.0,
+            material: MaterialGrade::C50,
+        };
+        let mesh = kernel.girder_mesh(&ir)?;
+        parts.push(translate(mesh, x, 0.0, 0.0));
+    }
+
+    // ── Deck Slab ──────────────────────────────────────────────────────────────
+    // KDS: min 220 mm, width = (N-1)*spacing + 2 × cantilever
+    let half_width = ((N_GIRDERS as f32 - 1.0) * SPACING) * 0.5 + 1_000.0; // 1 m cantilever
+    let deck_ir = DeckSlabIR {
+        id:            FeatureId::new(),
+        station_start: 0.0,
+        station_end:   SPAN_M,
+        width_left:    half_width as f64,
+        width_right:   half_width as f64,
+        thickness:     220.0,
+        haunch_depth:  0.0,
+        cross_slope:   2.0,
+        material:      MaterialGrade::C40,
+    };
+    let deck_mesh = kernel.deck_slab_mesh(&deck_ir)?;
+    // Slab Y=0 is its top face; place it so bottom aligns with girder top
+    parts.push(translate(deck_mesh, 0.0, GIRDER_H + 220.0, 0.0));
+
+    // ── Bearings ───────────────────────────────────────────────────────────────
+    // 5 per abutment, one under each girder
+    for &z in &[0.0_f32, SPAN_MM] {
+        for i in 0..N_GIRDERS {
+            let x = (i as f32 - (N_GIRDERS as f32 - 1.0) * 0.5) * SPACING;
+            let bearing_ir = BearingIR {
+                id:                FeatureId::new(),
+                station:           if z < 1.0 { 0.0 } else { SPAN_M },
+                bearing_type:      BearingType::Elastomeric,
+                plan_length:       350.0,
+                plan_width:        450.0,
+                total_height:      BEARING_H as f64,
+                capacity_vertical: 1_500.0,
+            };
+            let mesh = kernel.bearing_mesh(&bearing_ir)?;
+            // Place bearing centred under each girder, top at Y=0 (girder soffit)
+            parts.push(translate(mesh, x - 175.0, -BEARING_H, z - 225.0));
+        }
+    }
+
+    // ── Abutments ──────────────────────────────────────────────────────────────
+    let wing = WingWallIR { length: 5_000.0, height: 2_500.0, thickness: 500.0 };
+    let total_w = (N_GIRDERS as f64 - 1.0) * SPACING as f64 + 3_000.0; // incl. overhangs
+
+    for &(station, z) in &[(0.0f64, -800.0_f32), (SPAN_M, SPAN_MM)] {
+        let abut_ir = AbutmentIR {
+            id:                      FeatureId::new(),
+            station,
+            skew_angle:              0.0,
+            abutment_type:           AbutmentType::ReverseT,
+            breast_wall_height:      (GIRDER_H + BEARING_H) as f64,
+            breast_wall_thickness:   800.0,
+            breast_wall_width:       total_w,
+            footing_length:          4_000.0,
+            footing_width:           total_w + 1_000.0,
+            footing_thickness:       1_000.0,
+            wing_wall_left:          wing.clone(),
+            wing_wall_right:         wing.clone(),
+            material:                MaterialGrade::C40,
+        };
+        let mesh = kernel.abutment_mesh(&abut_ir)?;
+        // Place abutment: breast wall top at Y = -(BEARING_H)
+        let y = -(BEARING_H + abut_ir.breast_wall_height as f32);
+        parts.push(translate(mesh, -(total_w as f32) * 0.5, y, z));
+    }
+
+    Ok(merge(parts))
+}
+
+/// Bounding box of the full bridge scene (for camera setup).
+pub fn scene_extents() -> ([f32; 3], [f32; 3]) {
+    const SPAN_MM: f32 = 40_000.0;
+    const HALF_W:  f32 = 6_500.0;
+    const TOP_Y:   f32 = 2_020.0;  // top of slab
+    const BOT_Y:   f32 = -3_000.0; // footing bottom approx
+    ([-HALF_W, BOT_Y, -2_000.0], [HALF_W, TOP_Y, SPAN_MM + 2_000.0])
+}

cimery/crates/viewer/src/lib.rs

@@ -12,6 +12,7 @@
 //! - Add selection highlight.
 
 pub mod camera;
+pub mod bridge_scene;
 
 use std::sync::Arc;
 use bytemuck::{Pod, Zeroable};
@@ -31,6 +32,7 @@ use cimery_kernel::OcctKernel;
 use cimery_kernel::PureRustKernel;
 use cimery_kernel::GeomKernel;
 use camera::Camera;
+use glam;
 
 // ─── Vertex ───────────────────────────────────────────────────────────────────
 
@@ -139,23 +141,14 @@ impl RenderState {
         // ── Depth texture ─────────────────────────────────────────────────────
         let depth_view = Self::make_depth_view(&device, &surface_config);
 
-        // ── Test girder mesh via StubKernel ───────────────────────────────────
+        // ── Full bridge scene (Sprint 4) ──────────────────────────────────────
-        // Sprint 3: replace StubKernel with OcctKernel when OCCT compiles.
+        // Girder + DeckSlab + Bearing + Abutment
-        let test_ir = GirderIR {
-            id:                    FeatureId::new(),
-            station_start:         0.0,
-            station_end:           40.0,
-            offset_from_alignment: 0.0,
-            section_type:          SectionType::PscI,
-            section: SectionParams::PscI(PscISectionParams::kds_standard()),
-            count:    1,
-            spacing:  0.0,
-            material: MaterialGrade::C50,
-        };
         #[cfg(feature = "occt")]
-        let mesh = OcctKernel.girder_mesh(&test_ir).expect("OcctKernel mesh");
+        let mesh = bridge_scene::build_bridge_scene(&OcctKernel)
+            .expect("OcctKernel bridge scene");
         #[cfg(not(feature = "occt"))]
-        let mesh = PureRustKernel.girder_mesh(&test_ir).expect("PureRustKernel mesh");
+        let mesh = bridge_scene::build_bridge_scene(&PureRustKernel)
+            .expect("PureRustKernel bridge scene");
 
         let verts: Vec<Vertex> = mesh.vertices.iter().zip(mesh.normals.iter())
             .map(|(p, n)| Vertex { position: *p, normal: *n })
@@ -174,7 +167,23 @@ impl RenderState {
         let num_indices = mesh.indices.len() as u32;
 
         // ── Camera ────────────────────────────────────────────────────────────
-        let mut camera = Camera::default_for_girder(mesh.aabb().1[2]);  // span from AABB
+        // Camera for full bridge scene
+        let (mn, mx) = bridge_scene::scene_extents();
+        let cx = (mn[0] + mx[0]) * 0.5;
+        let cy = (mn[1] + mx[1]) * 0.5;
+        let cz = (mn[2] + mx[2]) * 0.5;
+        let span = (mx[2] - mn[2]).max(mx[0] - mn[0]);
+        let mut camera = Camera {
+            target:  glam::Vec3::new(cx, cy, cz),
+            radius:  span * 1.2,
+            yaw:     std::f32::consts::FRAC_PI_4,
+            pitch:   0.30,
+            fov_y:   60.0_f32.to_radians(),
+            aspect:  16.0 / 9.0,
+            znear:   10.0,
+            zfar:    10_000_000.0,
+        };
+        let _ = mesh.aabb(); // keep aabb call for future use
         camera.resize(surface_config.width, surface_config.height);
 
         let camera_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
@@ -384,9 +393,9 @@ impl ApplicationHandler for CimeryApp {
     fn resumed(&mut self, event_loop: &ActiveEventLoop) {
         let attrs = Window::default_attributes()
             .with_title(if cfg!(feature = "occt") {
-                "cimery viewer [Sprint 3 — OcctKernel B-rep]"
+                "cimery viewer [Sprint 4 — Full Bridge / OcctKernel]"
             } else {
-                "cimery viewer [Sprint 2 — PSC-I PureRustKernel]"
+                "cimery viewer [Sprint 4 — Full Bridge / PureRustKernel]"
             })
             .with_inner_size(winit::dpi::LogicalSize::new(1280u32, 720u32));
         let window = Arc::new(