Sprint 9/10 — 지면+선형 시각화 + 피처 선택

Sprint 9 (bridge_scene):
- 지면(Ground plane): 교량 하부 어두운 올리브 색 평면
- 선형(Alignment): 주황색 얇은 봉 (Z축 방향 경간 전체)
- 색상 추가: COL_GROUND, COL_ALIGNMENT

Sprint 10 (selection):
- FeatureDraw: 피처별 GPU 버퍼 + AABB + 선택 상태
- build_selectable_scene(): 거더/슬래브/받침/교대 개별 메시
- ray_aabb(): 레이-AABB 교차 판정 (좌클릭 피킹)
- egui 패널: 선택된 피처 이름 오렌지색 표시
- 선택 하이라이트는 Sprint 11에서 색상 override로 구현

cargo check 통과

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

cimery/crates/viewer/src/bridge_scene.rs

@@ -51,6 +51,8 @@ pub const COL_GIRDER:   [f32; 3] = [0.85, 0.82, 0.72]; // light concrete
 pub const COL_DECK:      [f32; 3] = [0.72, 0.70, 0.62]; // slightly darker slab
 pub const COL_BEARING:   [f32; 3] = [0.30, 0.30, 0.35]; // dark rubber/steel
 pub const COL_ABUTMENT:  [f32; 3] = [0.65, 0.60, 0.50]; // brown concrete
+pub const COL_GROUND:    [f32; 3] = [0.35, 0.38, 0.30]; // dark olive ground
+pub const COL_ALIGNMENT: [f32; 3] = [1.00, 0.60, 0.10]; // orange centreline
 
 // ─── Helpers ─────────────────────────────────────────────────────────────────
 
@@ -175,9 +177,133 @@ pub fn build_bridge_scene<K: GeomKernel>(kernel: &K, p: &SceneParams) -> Result<
         parts.push(translate(mesh, 0.0, y, z));
     }
 
+    // ── Ground plane ───────────────────────────────────────────────────────────
+    {
+        let ground_y  = -(BEARING_H + breast_wall_h as f32 + 1_000.0 + 200.0); // footing bottom - margin
+        let hw        = total_w as f32 * 0.5 + 8_000.0;   // wider than bridge
+        let half_z    = span_mm * 0.5 + 8_000.0;
+        let thickness = 500.0_f32;
+        let profile   = vec![
+            [-hw, -thickness], [hw, -thickness], [hw, 0.0], [-hw, 0.0],
+        ];
+        let mut ground = cimery_kernel::sweep::sweep_profile_flat(&profile, half_z * 2.0);
+        ground.recolor(COL_GROUND);
+        parts.push(translate(ground, 0.0, ground_y, -half_z));
+    }
+
+    // ── Alignment centreline ───────────────────────────────────────────────────
+    {
+        let radius = 80.0_f32;  // thin rod
+        let mut align = cimery_kernel::sweep::polygon_prism(0.0, 0.0, radius, 8, span_mm);
+        align.recolor(COL_ALIGNMENT);
+        parts.push(translate(align, 0.0, girder_h * 0.5, 0.0));
+    }
+
     Ok(merge(parts))
 }
 
+// ─── Selectable scene (per-feature meshes) ────────────────────────────────────
+
+pub struct FeatureMesh {
+    pub mesh:  Mesh,
+    pub label: String,
+}
+
+/// Build bridge scene as a list of individually-selectable feature meshes.
+pub fn build_selectable_scene<K: GeomKernel>(
+    kernel: &K,
+    p: &SceneParams,
+) -> Result<Vec<FeatureMesh>, KernelError> {
+    let span_m    = p.span_m;
+    let span_mm   = (p.span_m * 1_000.0) as f32;
+    let n_girders = p.girder_count.max(1).min(10);
+    let spacing   = p.girder_spacing;
+    let girder_h  = p.girder_height;
+    const BEARING_H: f32 = 60.0;
+
+    let section = PscISectionParams {
+        total_height:            girder_h as f64,
+        top_flange_width:        600.0,
+        top_flange_thickness:    150.0,
+        bottom_flange_width:     700.0,
+        bottom_flange_thickness: 180.0,
+        web_thickness:           200.0,
+        haunch:                  50.0,
+    };
+
+    let mut out: Vec<FeatureMesh> = 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(section.clone()),
+            count: 1, spacing: 0.0, material: MaterialGrade::C50,
+        };
+        let mut mesh = kernel.girder_mesh(&ir)?;
+        mesh.recolor(COL_GIRDER);
+        for v in &mut mesh.vertices { v[0] += x; }
+        out.push(FeatureMesh { mesh, label: format!("거더 {}", i + 1) });
+    }
+
+    // Deck Slab (one unit)
+    let half_w = ((n_girders as f32 - 1.0) * spacing) * 0.5 + 1_000.0;
+    let deck_ir = DeckSlabIR {
+        id: FeatureId::new(), station_start: 0.0, station_end: span_m,
+        width_left: half_w as f64, width_right: half_w as f64,
+        thickness: p.slab_thickness as f64, haunch_depth: 0.0,
+        cross_slope: 2.0, material: MaterialGrade::C40,
+    };
+    let mut deck = kernel.deck_slab_mesh(&deck_ir)?;
+    deck.recolor(COL_DECK);
+    for v in &mut deck.vertices { v[1] += girder_h + p.slab_thickness; }
+    out.push(FeatureMesh { mesh: deck, label: "바닥판 슬래브".into() });
+
+    // Bearings
+    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 bir = 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 mut mesh = kernel.bearing_mesh(&bir)?;
+            mesh.recolor(COL_BEARING);
+            for v in &mut mesh.vertices { v[0] += x; v[2] += z - 225.0; }
+            let side = if z < 1.0 { "시작" } else { "종점" };
+            out.push(FeatureMesh { mesh, label: format!("받침 {}-{}", side, i + 1) });
+        }
+    }
+
+    // Abutments
+    let total_w = (n_girders as f64 - 1.0) * spacing as f64 + 3_000.0;
+    let bwh = (girder_h + BEARING_H) as f64;
+    let wing = WingWallIR { length: 5_000.0, height: 2_500.0, thickness: 500.0 };
+    for &(station, z) in &[(0.0f64, -800.0_f32), (span_m, span_mm)] {
+        let air = AbutmentIR {
+            id: FeatureId::new(), station, skew_angle: 0.0,
+            abutment_type: AbutmentType::ReverseT,
+            breast_wall_height: bwh, 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 mut mesh = kernel.abutment_mesh(&air)?;
+        mesh.recolor(COL_ABUTMENT);
+        let y = -(BEARING_H + bwh as f32);
+        for v in &mut mesh.vertices { v[1] += y; v[2] += z; }
+        let side = if z < 0.0 { "시작" } else { "종점" };
+        out.push(FeatureMesh { mesh, label: format!("교대 ({})", side) });
+    }
+
+    Ok(out)
+}
+
 /// Bounding box of the full bridge scene (for camera setup).
 pub fn scene_extents(p: &SceneParams) -> ([f32; 3], [f32; 3]) {
     let span_mm  = (p.span_m * 1_000.0) as f32;

cimery/crates/viewer/src/lib.rs

@@ -23,7 +23,7 @@ use cimery_kernel::OcctKernel;
 use cimery_kernel::PureRustKernel;
 use camera::{Camera, StandardView};
 use glam;
-use bridge_scene::{SceneParams, build_bridge_scene, scene_extents};
+use bridge_scene::{SceneParams, build_bridge_scene, build_selectable_scene, scene_extents};
 
 // ─── Vertex ───────────────────────────────────────────────────────────────────
 
@@ -54,6 +54,62 @@ impl Vertex {
 
 const DEPTH_FORMAT: wgpu::TextureFormat = wgpu::TextureFormat::Depth32Float;
 
+// ─── Per-feature draw unit ───────────────────────────────────────────────────
+
+/// One selectable draw unit: a single Feature's GPU buffers + AABB.
+struct FeatureDraw {
+    vertex_buffer: wgpu::Buffer,
+    index_buffer:  wgpu::Buffer,
+    num_indices:   u32,
+    aabb_min:      [f32; 3],
+    aabb_max:      [f32; 3],
+    label:         String,          // e.g. "거더 2", "교대 (시작)"
+    selected:      bool,
+    base_color:    [f32; 3],        // original colour (for deselect)
+}
+
+impl FeatureDraw {
+    fn from_mesh(device: &wgpu::Device, mesh: &cimery_kernel::Mesh, label: &str) -> Self {
+        let verts: Vec<Vertex> = mesh.vertices.iter()
+            .zip(mesh.normals.iter()).zip(mesh.colors.iter())
+            .map(|((p, n), c)| Vertex { position: *p, normal: *n, base_color: *c })
+            .collect();
+        let vbuf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+            label: Some("feature vbuf"), contents: bytemuck::cast_slice(&verts),
+            usage: wgpu::BufferUsages::VERTEX,
+        });
+        let ibuf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+            label: Some("feature ibuf"), contents: bytemuck::cast_slice(&mesh.indices),
+            usage: wgpu::BufferUsages::INDEX,
+        });
+        let (mn, mx) = mesh.aabb();
+        let base = if mesh.colors.is_empty() { [0.8_f32, 0.76, 0.65] } else { mesh.colors[0] };
+        Self {
+            vertex_buffer: vbuf, index_buffer: ibuf,
+            num_indices: mesh.indices.len() as u32,
+            aabb_min: mn, aabb_max: mx, label: label.to_owned(),
+            selected: false, base_color: base,
+        }
+    }
+}
+
+// ─── Ray casting ─────────────────────────────────────────────────────────────
+
+/// Ray-AABB intersection test (slab method). Returns distance or None.
+fn ray_aabb(
+    ray_origin: glam::Vec3, ray_dir: glam::Vec3,
+    mn: [f32;3], mx: [f32;3],
+) -> Option<f32> {
+    let mn = glam::Vec3::from(mn);
+    let mx = glam::Vec3::from(mx);
+    let inv = 1.0 / ray_dir;
+    let t1 = (mn - ray_origin) * inv;
+    let t2 = (mx - ray_origin) * inv;
+    let tmin = t1.min(t2).max_element();
+    let tmax = t1.max(t2).min_element();
+    if tmax >= tmin && tmax > 0.0 { Some(tmin.max(0.0)) } else { None }
+}
+
 // ─── RenderState ─────────────────────────────────────────────────────────────
 
 struct RenderState {
@@ -63,7 +119,9 @@ struct RenderState {
     surface:          wgpu::Surface<'static>,
     surface_config:   wgpu::SurfaceConfiguration,
     render_pipeline:  wgpu::RenderPipeline,
-    // Mesh
+    // Per-feature draw units (Sprint 10)
+    features:         Vec<FeatureDraw>,
+    // Legacy single-mesh (kept for overlay/ground features without selection)
     vertex_buffer:    wgpu::Buffer,
     index_buffer:     wgpu::Buffer,
     num_indices:      u32,
@@ -76,6 +134,7 @@ struct RenderState {
     // Mouse / keyboard state
     mid_pressed:     bool,
     shift_pressed:   bool,
+    left_just_pressed: bool,
     last_mouse:      winit::dpi::PhysicalPosition<f64>,
     // Scene extents for ZoomExtents
     scene_mn:      [f32; 3],
@@ -325,13 +384,15 @@ impl RenderState {
             camera_buffer,
             camera_bind_group,
             depth_view,
+            features:         vec![],         // filled by first rebuild_mesh
             mid_pressed:      false,
             shift_pressed:    false,
+            left_just_pressed:false,
             last_mouse:       winit::dpi::PhysicalPosition { x: 0.0, y: 0.0 },
             scene_mn,
             scene_mx,
             params,
-            dirty:         false,
+            dirty:         true,             // trigger initial feature build
             egui_ctx,
             egui_state,
             egui_renderer,
@@ -362,36 +423,46 @@ impl RenderState {
         .create_view(&wgpu::TextureViewDescriptor::default())
     }
 
-    /// Rebuild GPU buffers from current SceneParams. Called when `dirty` is set.
+    /// Rebuild GPU buffers from current SceneParams.
     fn rebuild_mesh(&mut self) {
+        // Build merged mesh (ground + alignment, for background draw)
         #[cfg(feature = "occt")]
-        let mesh = build_bridge_scene(&OcctKernel, &self.params);
+        let full_mesh = build_bridge_scene(&OcctKernel, &self.params);
         #[cfg(not(feature = "occt"))]
-        let mesh = build_bridge_scene(&PureRustKernel, &self.params);
+        let full_mesh = build_bridge_scene(&PureRustKernel, &self.params);
 
-        if let Ok(mesh) = mesh {
+        if let Ok(mesh) = full_mesh {
             let verts: Vec<Vertex> = mesh.vertices.iter()
                 .zip(mesh.normals.iter()).zip(mesh.colors.iter())
                 .map(|((p, n), c)| Vertex { position: *p, normal: *n, base_color: *c })
                 .collect();
             self.vertex_buffer = self.device.create_buffer_init(
                 &wgpu::util::BufferInitDescriptor {
-                    label:    Some("mesh vertex buffer"),
+                    label: Some("merged vbuf"), contents: bytemuck::cast_slice(&verts),
-                    contents: bytemuck::cast_slice(&verts),
                     usage: wgpu::BufferUsages::VERTEX,
                 });
             self.index_buffer = self.device.create_buffer_init(
                 &wgpu::util::BufferInitDescriptor {
-                    label:    Some("mesh index buffer"),
+                    label: Some("merged ibuf"), contents: bytemuck::cast_slice(&mesh.indices),
-                    contents: bytemuck::cast_slice(&mesh.indices),
                     usage: wgpu::BufferUsages::INDEX,
                 });
             self.num_indices = mesh.indices.len() as u32;
-            // Update camera extents
+        }
+
+        // Build per-feature meshes for selection (Sprint 10)
+        #[cfg(feature = "occt")]
+        let sel = build_selectable_scene(&OcctKernel, &self.params);
+        #[cfg(not(feature = "occt"))]
+        let sel = build_selectable_scene(&PureRustKernel, &self.params);
+        if let Ok(feature_meshes) = sel {
+            self.features = feature_meshes.into_iter()
+                .map(|fm| FeatureDraw::from_mesh(&self.device, &fm.mesh, &fm.label))
+                .collect();
+        }
+
         let (mn, mx) = scene_extents(&self.params);
         self.scene_mn = mn;
         self.scene_mx = mx;
-        }
         self.dirty = false;
     }
 
@@ -416,8 +487,35 @@ impl RenderState {
 
     fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
         // ── egui UI (use local copies to avoid self-borrow in closure) ───────
+        // Handle pick on left click (before egui, so egui can consume)
+        if self.left_just_pressed {
+            self.left_just_pressed = false;
+            let mx = self.last_mouse.x as f32;
+            let my = self.last_mouse.y as f32;
+            let w  = self.surface_config.width  as f32;
+            let h  = self.surface_config.height as f32;
+            // Compute ray from camera through pixel
+            let ndc_x =  (mx / w) * 2.0 - 1.0;
+            let ndc_y = -(my / h) * 2.0 + 1.0;
+            let vp_inv = self.camera.view_proj().inverse();
+            let near = vp_inv.project_point3(glam::Vec3::new(ndc_x, ndc_y, 0.0));
+            let far  = vp_inv.project_point3(glam::Vec3::new(ndc_x, ndc_y, 1.0));
+            let ray_dir = (far - near).normalize();
+            // Hit test against each feature AABB
+            let mut best: Option<(f32, usize)> = None;
+            for (i, feat) in self.features.iter().enumerate() {
+                if let Some(t) = ray_aabb(near, ray_dir, feat.aabb_min, feat.aabb_max) {
+                    if best.map_or(true, |(bt, _)| t < bt) { best = Some((t, i)); }
+                }
+            }
+            // Update selection
+            for feat in &mut self.features { feat.selected = false; }
+            if let Some((_, idx)) = best { self.features[idx].selected = true; }
+        }
+
         let raw_input = self.egui_state.take_egui_input(&self.window);
         let mut p           = self.params.clone();
+        let p_features      = &self.features;   // borrow for egui display only
         let mut dirty       = self.dirty;
         let was_dirty       = dirty;
         let mut apply       = false;
@@ -452,6 +550,15 @@ impl RenderState {
                         ui.label("✓ 최신 상태");
                     }
 
+                    ui.separator();
+                    // Selected feature info
+                    if let Some(idx) = p_features.iter().position(|f| f.selected) {
+                        ui.colored_label(egui::Color32::from_rgb(255, 170, 50),
+                            format!("▶ {}", p_features[idx].label));
+                    } else {
+                        ui.small("(클릭으로 피처 선택)");
+                    }
+
                     ui.separator();
                     ui.label("카메라 단축키");
                     ui.small("E: 전체뷰  7: 평면도");
@@ -642,6 +749,12 @@ impl ApplicationHandler for CimeryApp {
             // ── Resize ────────────────────────────────────────────────────────
             WindowEvent::Resized(sz) => state.resize(sz),
 
+            // ── Left click: pick feature ──────────────────────────────────────
+            WindowEvent::MouseInput { button: MouseButton::Left, state: btn_state, .. } => {
+                if btn_state == ElementState::Pressed {
+                    state.left_just_pressed = true;
+                }
+            }
             // ── Mouse orbit / pan (middle button drag) ────────────────────────
             WindowEvent::MouseInput { button: MouseButton::Middle, state: btn_state, .. } => {
                 state.mid_pressed = btn_state == ElementState::Pressed;