Sprint 5 — 인터랙티브 파라메트릭 + egui 속성 패널

- SceneParams: 경간/거더수/간격/높이/슬래브두께 — 실시간 변경 가능
- egui SidePanel(좌측): 슬라이더 편집 → ▶ 적용 → 씬 재생성
- rebuild_mesh(): 파라미터 변경 시 GPU 버텍스·인덱스 버퍼 재생성
- wgpu 22 + egui-wgpu 0.29: forget_lifetime() 로 render pass 전달
- 3D 인코더와 egui 인코더 분리 (wgpu 22 lifetime 호환)
- build_bridge_scene(&SceneParams): 경간·거더수·간격 파라메트릭

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

cimery/crates/viewer/Cargo.toml

@@ -23,3 +23,7 @@ pollster      = "0.3"
 glam          = "0.29"
 cimery-ir     = { workspace = true }
 cimery-core   = { workspace = true }
+cimery-incremental = { workspace = true }
+egui          = "0.29"
+egui-wgpu     = "0.29"
+egui-winit    = "0.29"

cimery/crates/viewer/src/bridge_scene.rs

@@ -16,6 +16,36 @@ use cimery_ir::{
 };
 use cimery_kernel::{GeomKernel, KernelError, Mesh};
 
+// ─── Scene parameters (user-editable) ────────────────────────────────────────
+
+/// Parameters that define the bridge geometry.
+/// Changing any field and calling `build_bridge_scene` regenerates the mesh.
+#[derive(Debug, Clone)]
+pub struct SceneParams {
+    /// Girder span [m]. Range 20–80 m.
+    pub span_m:         f64,
+    /// Number of girders (3–6).
+    pub girder_count:   usize,
+    /// Girder centre-to-centre spacing [mm].
+    pub girder_spacing: f32,
+    /// PSC-I total height [mm].
+    pub girder_height:  f32,
+    /// Slab thickness [mm].
+    pub slab_thickness: f32,
+}
+
+impl Default for SceneParams {
+    fn default() -> Self {
+        Self {
+            span_m:         40.0,
+            girder_count:   5,
+            girder_spacing: 2_500.0,
+            girder_height:  1_800.0,
+            slab_thickness: 220.0,
+        }
+    }
+}
+
 // ── Part colours (linear sRGB) ──────────────────────────────────────────────
 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
@@ -39,14 +69,14 @@ fn merge(meshes: Vec<Mesh>) -> Mesh {
 
 // ─── Scene builder ────────────────────────────────────────────────────────────
 
-/// Build a complete bridge scene mesh using the provided kernel.
+/// Build a complete bridge scene mesh using the provided kernel and parameters.
-pub fn build_bridge_scene<K: GeomKernel>(kernel: &K) -> Result<Mesh, KernelError> {
+pub fn build_bridge_scene<K: GeomKernel>(kernel: &K, p: &SceneParams) -> Result<Mesh, KernelError> {
-    const SPAN_M:       f64 = 40.0;
+    let SPAN_M       = p.span_m;
-    const SPAN_MM:      f32 = 40_000.0;
+    let SPAN_MM      = (p.span_m * 1_000.0) as f32;
-    const N_GIRDERS:    usize = 5;
+    let N_GIRDERS    = p.girder_count.max(1).min(10);
-    const SPACING:      f32 = 2_500.0;   // mm c/c
+    let SPACING      = p.girder_spacing;
-    const GIRDER_H:     f32 = 1_800.0;   // mm
+    let GIRDER_H     = p.girder_height;
-    const BEARING_H:    f32 = 60.0;      // mm
+    const BEARING_H: f32 = 60.0;      // mm
 
     let mut parts: Vec<Mesh> = Vec::new();
 
@@ -78,14 +108,14 @@ pub fn build_bridge_scene<K: GeomKernel>(kernel: &K) -> Result<Mesh, KernelError
         station_end:   SPAN_M,
         width_left:    half_width as f64,
         width_right:   half_width as f64,
-        thickness:     220.0,
+        thickness:     p.slab_thickness as f64,
         haunch_depth:  0.0,
         cross_slope:   2.0,
         material:      MaterialGrade::C40,
     };
     let mut deck_mesh = kernel.deck_slab_mesh(&deck_ir)?;
     deck_mesh.recolor(COL_DECK);
-    parts.push(translate(deck_mesh, 0.0, GIRDER_H + 220.0, 0.0));
+    parts.push(translate(deck_mesh, 0.0, GIRDER_H + p.slab_thickness, 0.0));
 
     // ── Bearings ───────────────────────────────────────────────────────────────
     // 5 per abutment, one under each girder
@@ -109,7 +139,8 @@ pub fn build_bridge_scene<K: GeomKernel>(kernel: &K) -> Result<Mesh, KernelError
 
     // ── 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
+    let total_w = (N_GIRDERS as f64 - 1.0) * SPACING as f64 + 3_000.0;
+    let breast_wall_h = (GIRDER_H + BEARING_H) as f64;
 
     for &(station, z) in &[(0.0f64, -800.0_f32), (SPAN_M, SPAN_MM)] {
         let abut_ir = AbutmentIR {
@@ -117,7 +148,7 @@ pub fn build_bridge_scene<K: GeomKernel>(kernel: &K) -> Result<Mesh, KernelError
             station,
             skew_angle:              0.0,
             abutment_type:           AbutmentType::ReverseT,
-            breast_wall_height:      (GIRDER_H + BEARING_H) as f64,
+            breast_wall_height:      breast_wall_h,
             breast_wall_thickness:   800.0,
             breast_wall_width:       total_w,
             footing_length:          4_000.0,
@@ -137,10 +168,10 @@ pub fn build_bridge_scene<K: GeomKernel>(kernel: &K) -> Result<Mesh, KernelError
 }
 
 /// Bounding box of the full bridge scene (for camera setup).
-pub fn scene_extents() -> ([f32; 3], [f32; 3]) {
+pub fn scene_extents(p: &SceneParams) -> ([f32; 3], [f32; 3]) {
-    const SPAN_MM: f32 = 40_000.0;
+    let span_mm  = (p.span_m * 1_000.0) as f32;
-    const HALF_W:  f32 = 6_500.0;
+    let half_w   = ((p.girder_count as f32 - 1.0) * p.girder_spacing * 0.5 + 2_000.0).max(5_000.0);
-    const TOP_Y:   f32 = 2_020.0;  // top of slab
+    let top_y    = p.girder_height + p.slab_thickness + 200.0;
-    const BOT_Y:   f32 = -3_000.0; // footing bottom approx
+    let bot_y    = -(p.girder_height + 3_000.0 + 1_000.0);
-    ([-HALF_W, BOT_Y, -2_000.0], [HALF_W, TOP_Y, SPAN_MM + 2_000.0])
+    ([-half_w, bot_y, -2_000.0], [half_w, top_y, span_mm + 2_000.0])
 }

cimery/crates/viewer/src/lib.rs

@@ -1,15 +1,7 @@
-//! cimery-viewer — Sprint 2.
+//! cimery-viewer — Sprint 5: Interactive Parametric.
 //!
-//! Renders a PSC-I girder mesh (from StubKernel or OcctKernel) with:
+//! egui Properties panel (left) + real-time bridge scene regeneration.
-//! - Perspective camera (Revit-style orbit: middle-mouse drag + scroll)
+//! Parameter change → rebuild_mesh() → new GPU buffers → immediate redraw.
-//! - Depth buffer
-//! - Simple directional lighting from surface normals
-//! - Back-face culling
-//!
-//! # Sprint 3 upgrade path
-//! - Swap `StubKernel` → `OcctKernel` once OCCT compiles.
-//! - Add ViewCube widget overlay.
-//! - Add selection highlight.
 
 pub mod camera;
 pub mod bridge_scene;
@@ -30,6 +22,7 @@ use cimery_kernel::OcctKernel;
 use cimery_kernel::PureRustKernel;
 use camera::{Camera, StandardView};
 use glam;
+use bridge_scene::{SceneParams, build_bridge_scene, scene_extents};
 
 // ─── Vertex ───────────────────────────────────────────────────────────────────
 
@@ -80,12 +73,19 @@ struct RenderState {
     // Depth
     depth_view:       wgpu::TextureView,
     // Mouse / keyboard state
-    mid_pressed:  bool,
+    mid_pressed:   bool,
     shift_pressed: bool,
-    last_mouse:   winit::dpi::PhysicalPosition<f64>,
+    last_mouse:    winit::dpi::PhysicalPosition<f64>,
     // Scene extents for ZoomExtents
-    scene_mn:     [f32; 3],
+    scene_mn:      [f32; 3],
-    scene_mx:     [f32; 3],
+    scene_mx:      [f32; 3],
+    // Scene parameters (user-editable via egui panel)
+    params:        SceneParams,
+    dirty:         bool,            // needs mesh rebuild
+    // egui
+    egui_ctx:      egui::Context,
+    egui_state:    egui_winit::State,
+    egui_renderer: egui_wgpu::Renderer,
 }
 
 impl RenderState {
@@ -144,14 +144,12 @@ impl RenderState {
         // ── Depth texture ─────────────────────────────────────────────────────
         let depth_view = Self::make_depth_view(&device, &surface_config);
 
-        // ── Full bridge scene (Sprint 4) ──────────────────────────────────────
+        // ── Bridge scene (parametric) ─────────────────────────────────────────
-        // Girder + DeckSlab + Bearing + Abutment
+        let params = SceneParams::default();
         #[cfg(feature = "occt")]
-        let mesh = bridge_scene::build_bridge_scene(&OcctKernel)
+        let mesh = build_bridge_scene(&OcctKernel, &params).expect("bridge scene");
-            .expect("OcctKernel bridge scene");
         #[cfg(not(feature = "occt"))]
-        let mesh = bridge_scene::build_bridge_scene(&PureRustKernel)
+        let mesh = build_bridge_scene(&PureRustKernel, &params).expect("bridge scene");
-            .expect("PureRustKernel bridge scene");
 
         let verts: Vec<Vertex> = mesh.vertices.iter()
             .zip(mesh.normals.iter())
@@ -173,7 +171,7 @@ impl RenderState {
 
         // ── Camera ────────────────────────────────────────────────────────────
         // Camera for full bridge scene
-        let (mn, mx) = bridge_scene::scene_extents();
+        let (mn, mx) = scene_extents(&params);
         let cx = (mn[0] + mx[0]) * 0.5;
         let cy = (mn[1] + mx[1]) * 0.5;
         let cz = (mn[2] + mx[2]) * 0.5;
@@ -276,7 +274,19 @@ impl RenderState {
             cache:     None,
         });
 
-        let (scene_mn, scene_mx) = bridge_scene::scene_extents();
+        let (scene_mn, scene_mx) = scene_extents(&params);
+
+        // ── egui ──────────────────────────────────────────────────────────────
+        let egui_ctx = egui::Context::default();
+        let egui_state = egui_winit::State::new(
+            egui_ctx.clone(),
+            egui::ViewportId::ROOT,
+            &*window,
+            None, None, None,
+        );
+        let egui_renderer = egui_wgpu::Renderer::new(
+            &device, format, Some(DEPTH_FORMAT), 1, false,
+        );
 
         RenderState {
             window,
@@ -297,6 +307,11 @@ impl RenderState {
             last_mouse:    winit::dpi::PhysicalPosition { x: 0.0, y: 0.0 },
             scene_mn,
             scene_mx,
+            params,
+            dirty:         false,
+            egui_ctx,
+            egui_state,
+            egui_renderer,
         }
     }
 
@@ -324,6 +339,39 @@ impl RenderState {
         .create_view(&wgpu::TextureViewDescriptor::default())
     }
 
+    /// Rebuild GPU buffers from current SceneParams. Called when `dirty` is set.
+    fn rebuild_mesh(&mut self) {
+        #[cfg(feature = "occt")]
+        let mesh = build_bridge_scene(&OcctKernel, &self.params);
+        #[cfg(not(feature = "occt"))]
+        let mesh = build_bridge_scene(&PureRustKernel, &self.params);
+
+        if let Ok(mesh) = 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"),
+                    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"),
+                    contents: bytemuck::cast_slice(&mesh.indices),
+                    usage:    wgpu::BufferUsages::INDEX,
+                });
+            self.num_indices = mesh.indices.len() as u32;
+            // Update camera extents
+            let (mn, mx) = scene_extents(&self.params);
+            self.scene_mn = mn;
+            self.scene_mx = mx;
+        }
+        self.dirty = false;
+    }
+
     fn update_camera(&self) {
         self.queue.write_buffer(
             &self.camera_buffer,
@@ -344,6 +392,66 @@ impl RenderState {
     }
 
     fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
+        // ── egui UI (use local copies to avoid self-borrow in closure) ───────
+        let raw_input = self.egui_state.take_egui_input(&self.window);
+        let mut p      = self.params.clone();
+        let mut dirty  = self.dirty;
+        let was_dirty  = dirty;
+        let mut apply  = false;
+
+        let full_output = self.egui_ctx.run(raw_input, |ctx| {
+            egui::SidePanel::left("properties")
+                .resizable(true)
+                .default_width(230.0)
+                .show(ctx, |ui| {
+                    ui.heading("교량 속성");
+                    ui.separator();
+
+                    let prev = p.span_m;
+                    ui.label("경간 (m)");
+                    ui.add(egui::Slider::new(&mut p.span_m, 20.0..=80.0).step_by(1.0));
+                    if (p.span_m - prev).abs() > 0.001 { dirty = true; }
+
+                    let prev = p.girder_count;
+                    ui.label("거더 수");
+                    ui.add(egui::Slider::new(&mut p.girder_count, 3..=7));
+                    if p.girder_count != prev { dirty = true; }
+
+                    let prev = p.girder_spacing;
+                    ui.label("c/c 간격 (mm)");
+                    ui.add(egui::Slider::new(&mut p.girder_spacing, 1_500.0..=4_000.0).step_by(100.0));
+                    if (p.girder_spacing - prev).abs() > 1.0 { dirty = true; }
+
+                    let prev = p.girder_height;
+                    ui.label("거더 높이 (mm)");
+                    ui.add(egui::Slider::new(&mut p.girder_height, 1_000.0..=3_000.0).step_by(100.0));
+                    if (p.girder_height - prev).abs() > 1.0 { dirty = true; }
+
+                    let prev = p.slab_thickness;
+                    ui.label("슬래브 두께 (mm)");
+                    ui.add(egui::Slider::new(&mut p.slab_thickness, 150.0..=400.0).step_by(10.0));
+                    if (p.slab_thickness - prev).abs() > 1.0 { dirty = true; }
+
+                    ui.separator();
+                    if dirty {
+                        apply = ui.button("▶ 적용").clicked();
+                    } else {
+                        ui.label("✓ 최신 상태");
+                    }
+
+                    ui.separator();
+                    ui.label("카메라 단축키");
+                    ui.small("E: 전체뷰  7: 평면도");
+                    ui.small("1: 정면  3: 측면  Home: 아이소");
+                    ui.small("가운데버튼: 회전  Shift+가운데: 팬");
+                });
+        });
+        self.egui_state.handle_platform_output(&self.window, full_output.platform_output);
+        self.params = p;
+        self.dirty  = dirty;
+        if apply { self.rebuild_mesh(); }
+
+        // ── 3D scene ─────────────────────────────────────────────────────────
         let output = self.surface.get_current_texture()?;
         let view   = output.texture.create_view(&Default::default());
         let mut enc = self.device.create_command_encoder(&wgpu::CommandEncoderDescriptor {
@@ -379,7 +487,49 @@ impl RenderState {
             rp.set_index_buffer(self.index_buffer.slice(..), wgpu::IndexFormat::Uint32);
             rp.draw_indexed(0..self.num_indices, 0, 0..1);
         }
+        // ── egui render ──────────────────────────────────────────────────────
+        let screen_desc = egui_wgpu::ScreenDescriptor {
+            size_in_pixels: [self.surface_config.width, self.surface_config.height],
+            pixels_per_point: self.window.scale_factor() as f32,
+        };
+        let tris = self.egui_ctx.tessellate(
+            full_output.shapes, screen_desc.pixels_per_point,
+        );
+        for (id, delta) in full_output.textures_delta.set {
+            self.egui_renderer.update_texture(&self.device, &self.queue, id, &delta);
+        }
+        // Submit 3D first
         self.queue.submit(std::iter::once(enc.finish()));
+
+        // egui uses its own encoder (avoids wgpu 22 lifetime issue)
+        let mut egui_enc = self.device.create_command_encoder(
+            &wgpu::CommandEncoderDescriptor { label: Some("egui encoder") },
+        );
+        self.egui_renderer.update_buffers(
+            &self.device, &self.queue, &mut egui_enc, &tris, &screen_desc,
+        );
+        {
+            // wgpu 22: use forget_lifetime() so render pass can be passed to egui renderer
+            let mut rp = egui_enc.begin_render_pass(&wgpu::RenderPassDescriptor {
+                label: Some("egui pass"),
+                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+                    view: &view, resolve_target: None,
+                    ops: wgpu::Operations {
+                        load: wgpu::LoadOp::Load, store: wgpu::StoreOp::Store,
+                    },
+                })],
+                depth_stencil_attachment: None,
+                occlusion_query_set:      None,
+                timestamp_writes:         None,
+            }).forget_lifetime();
+            self.egui_renderer.render(&mut rp, &tris, &screen_desc);
+        }
+        for id in full_output.textures_delta.free {
+            self.egui_renderer.free_texture(&id);
+        }
+        let _ = was_dirty;
+
+        self.queue.submit(std::iter::once(egui_enc.finish()));
         output.present();
         Ok(())
     }
@@ -423,6 +573,10 @@ impl ApplicationHandler for CimeryApp {
         let Some(state) = self.state.as_mut() else { return };
         if state.window.id() != window_id { return; }
 
+        // Forward to egui first; if egui consumes the event, skip camera
+        let egui_resp = state.egui_state.on_window_event(&state.window, &event);
+        if egui_resp.consumed { return; }
+
         match event {
             // ── Exit ──────────────────────────────────────────────────────────
             WindowEvent::CloseRequested => event_loop.exit(),