diff --git a/Makefile b/Makefile
index b91c4e1..cf2ce0d 100644
--- a/Makefile
+++ b/Makefile
@@ -272,10 +272,13 @@ gen_scene:
 			@$(CC) -Wall -Wextra -Werror -o gen_scene tools/gen_scene.c -lm
 			@echo "Built gen_scene tool"
 
+render-cathedral:	$(NAME) gen_scene
+			@scripts/render_cathedral.sh $(ARGS)
+
 testclean:
 			$(RM) run_test_math run_test_camera run_test_intersections run_test_lighting run_test_parsing run_test_pbr run_benchmark
 			$(RM) cov_test_math cov_test_intersections cov_test_lighting cov_test_parsing cov_test_all
 			$(RM) -r coverage
 			$(RM) *.gcno *.gcda src/*.gcno src/*.gcda tests/*.gcno tests/*.gcda
 
-.PHONY:		re all clean fclean sanitize debug release test testclean coverage regression regression-generate lint benchmark gen_scene
+.PHONY:		re all clean fclean sanitize debug release test testclean coverage regression regression-generate lint benchmark gen_scene render-cathedral
diff --git a/README.md b/README.md
index d5554e3..9493e33 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # miniRT
 
-![Cathedral Ruins](./saves/cathedral_ruins.bmp?raw=true)
+![Cathedral Ruins](./renders_preview/cathedral_ruins.png?raw=true)
 
 **A basic RayTracer using minilibX**    
 project of 42 Paris's common-core
diff --git a/renders_preview/cathedral_ruins.png b/renders_preview/cathedral_ruins.png
index c24288c..844915c 100644
Binary files a/renders_preview/cathedral_ruins.png and b/renders_preview/cathedral_ruins.png differ
diff --git a/saves/cathedral_ruins.bmp b/saves/cathedral_ruins.bmp
index 1d46077..fe99969 100755
Binary files a/saves/cathedral_ruins.bmp and b/saves/cathedral_ruins.bmp differ
diff --git a/saves/cathedral_ruins.png b/saves/cathedral_ruins.png
new file mode 100644
index 0000000..844915c
Binary files /dev/null and b/saves/cathedral_ruins.png differ
diff --git a/scenes/cathedral_ruins.rt b/scenes/cathedral_ruins.rt
index 1c86a47..771f7a3 100644
--- a/scenes/cathedral_ruins.rt
+++ b/scenes/cathedral_ruins.rt
@@ -2,7 +2,10 @@ R	2560	1440
 A	0.08	200,190,170
 E
 
-c	0.0,6.0,12.0	0.03,0,0	70
+c	0.0,12.0,25.0	0.055,0,0	70
+c	-4.0,7.0,18.0	0.04,-0.03,0	70
+c	8.0,6.0,-15.0	0.03,0.3,0	70
+c	0.0,2.0,16.0	0.0,0,0	70
 
 l	-3.0,25.0,-5.0	0.9	255,240,200
 l	5.0,20.0,5.0	0.6	255,235,190
diff --git a/scripts/bmp2png.py b/scripts/bmp2png.py
new file mode 100755
index 0000000..6e36f96
--- /dev/null
+++ b/scripts/bmp2png.py
@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+"""Convert BMP files to PNG format."""
+import sys
+from PIL import Image
+
+def convert(src, dst=None):
+    if dst is None:
+        dst = src.rsplit('.', 1)[0] + '.png'
+    img = Image.open(src)
+    img.save(dst, 'PNG')
+    print(f"{src} -> {dst} ({img.width}x{img.height})")
+
+if __name__ == '__main__':
+    if len(sys.argv) < 2:
+        print("Usage: bmp2png.py <input.bmp> [output.png]")
+        sys.exit(1)
+    convert(sys.argv[1], sys.argv[2] if len(sys.argv) > 2 else None)
diff --git a/scripts/render_cathedral.sh b/scripts/render_cathedral.sh
new file mode 100755
index 0000000..d5f65e7
--- /dev/null
+++ b/scripts/render_cathedral.sh
@@ -0,0 +1,129 @@
+#!/bin/bash
+# Render the cathedral ruins scene
+# Generates the .rt file via gen_scene and renders it with miniRT
+#
+# Usage: scripts/render_cathedral.sh [OPTIONS]
+#   --preview         Quick render at 640x360
+#   --full            Full resolution render (2560x1440)
+#   --generate-only   Create .rt file without rendering
+#   --png             Convert output BMP to PNG (requires Pillow)
+#   --width N         Custom width (default: 1280)
+#   --height N        Custom height (default: 720)
+#   --threads N       Thread count (default: auto)
+#   --seed N          RNG seed for debris placement (default: 42)
+#   --output PATH     Output BMP path (default: saves/cathedral_ruins.bmp)
+#   --scene PATH      Use existing .rt file instead of generating
+
+set -euo pipefail
+
+PROJECT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+
+WIDTH=1280
+HEIGHT=720
+THREADS="auto"
+SEED=42
+OUTPUT="$PROJECT_DIR/saves/cathedral_ruins.bmp"
+SCENE_FILE=""
+GENERATE_ONLY=0
+USE_EXISTING=0
+CONVERT_PNG=0
+
+while [ $# -gt 0 ]; do
+    case "$1" in
+        --preview)
+            WIDTH=640; HEIGHT=360 ;;
+        --full)
+            WIDTH=2560; HEIGHT=1440 ;;
+        --generate-only)
+            GENERATE_ONLY=1 ;;
+        --png)
+            CONVERT_PNG=1 ;;
+        --width)
+            WIDTH="$2"; shift ;;
+        --height)
+            HEIGHT="$2"; shift ;;
+        --threads)
+            THREADS="$2"; shift ;;
+        --seed)
+            SEED="$2"; shift ;;
+        --output)
+            OUTPUT="$2"; shift ;;
+        --scene)
+            SCENE_FILE="$2"; USE_EXISTING=1; shift ;;
+        --help|-h)
+            head -16 "$0" | tail -14
+            exit 0 ;;
+        *)
+            echo "Unknown option: $1" >&2
+            exit 1 ;;
+    esac
+    shift
+done
+
+# Build miniRT if missing
+if [ ! -f "$PROJECT_DIR/miniRT" ]; then
+    echo "Building miniRT..."
+    make -C "$PROJECT_DIR" -j"$(nproc)" 2>&1 | tail -1
+fi
+
+# Build gen_scene if missing
+if [ ! -f "$PROJECT_DIR/gen_scene" ]; then
+    echo "Building gen_scene..."
+    make -C "$PROJECT_DIR" gen_scene 2>&1
+fi
+
+# Generate scene file
+if [ "$USE_EXISTING" -eq 0 ]; then
+    SCENE_FILE="$PROJECT_DIR/scenes/cathedral_ruins_gen.rt"
+    echo "Generating cathedral scene (${WIDTH}x${HEIGHT}, seed=${SEED})..."
+    "$PROJECT_DIR/gen_scene" --preset cathedral \
+        --width "$WIDTH" --height "$HEIGHT" \
+        --seed "$SEED" \
+        --output "$SCENE_FILE"
+    echo "Scene file: $SCENE_FILE"
+    SHAPE_COUNT=$(grep -c "^[a-z]" "$SCENE_FILE" || true)
+    echo "Shape/element count: $SHAPE_COUNT"
+fi
+
+if [ "$GENERATE_ONLY" -eq 1 ]; then
+    echo "Done (generate-only mode)."
+    exit 0
+fi
+
+# Render
+mkdir -p "$(dirname "$OUTPUT")"
+echo ""
+echo "Rendering ${WIDTH}x${HEIGHT} with --threads=${THREADS}..."
+echo "Output: $OUTPUT"
+echo "This may take a while for large resolutions."
+echo ""
+
+START=$(date +%s)
+
+cd "$PROJECT_DIR"
+xvfb-run -a "$PROJECT_DIR/miniRT" "$SCENE_FILE" -save \
+    --output "$OUTPUT" --threads="$THREADS" || {
+    echo "Retrying with default output path..."
+    xvfb-run -a "$PROJECT_DIR/miniRT" "$SCENE_FILE" -save \
+        --threads="$THREADS"
+    mv -f "$PROJECT_DIR/miniRT.bmp" "$OUTPUT"
+}
+
+END=$(date +%s)
+ELAPSED=$((END - START))
+MINUTES=$((ELAPSED / 60))
+SECONDS=$((ELAPSED % 60))
+
+echo ""
+echo "=== Render Complete ==="
+echo "Time: ${MINUTES}m ${SECONDS}s"
+ls -lh "$OUTPUT" | awk '{print "Size:", $5}'
+file "$OUTPUT" | sed 's/.*: /Format: /'
+
+# Convert to PNG if requested
+if [ "$CONVERT_PNG" -eq 1 ]; then
+    PNG_OUTPUT="${OUTPUT%.bmp}.png"
+    echo ""
+    echo "Converting to PNG..."
+    python3 "$PROJECT_DIR/scripts/bmp2png.py" "$OUTPUT" "$PNG_OUTPUT"
+fi
diff --git a/skills/scene-design.md b/skills/scene-design.md
new file mode 100644
index 0000000..012d138
--- /dev/null
+++ b/skills/scene-design.md
@@ -0,0 +1,302 @@
+# Scene Design & Rendering Workflows
+
+## Architectural Scene Design Principles
+
+### Building from primitives
+
+Complex architectural scenes are built by composing simple shapes:
+
+| Architectural Element | Primary Shape | Supporting Shapes |
+|----------------------|---------------|-------------------|
+| Walls | `bx` (box) | Multiple boxes with gaps for ruin effect |
+| Columns/pillars | `cy` (cylinder) | `dk` (disk) base + `sp` (sphere) capital |
+| Gothic arches | `to` (torus) | Half-torus between column tops |
+| Floors | `pl` (plane) | `sq` (square) overlays for tile variation |
+| Roofs/vaults | `tr` (triangle) | Angled triangles + `sq` for panels |
+| Windows | `sq` with `trans:` | `sp` for round window tops (oculi) |
+| Towers | `cy` base | `co` (cone) roof |
+| Debris | `bx`, `sp`, `tr` | Mixed small shapes at ground level |
+| Vegetation | `el` (ellipsoid) | Organic shapes for ivy/moss |
+
+### Layered composition
+
+Build scenes in layers, from structural to atmospheric:
+
+1. **Structural shell** -- walls, floor plane, ceiling/roof
+2. **Architectural features** -- columns, arches, windows, altar
+3. **Decorative elements** -- crosses, candelabra, fonts, tomb slabs
+4. **Decay/wear** -- broken columns, rubble, fallen roof pieces
+5. **Atmospheric effects** -- dust motes, water puddles, stained glass light patches
+
+### Depth through repetition
+
+Colonnades (rows of repeated columns) and arcades (rows of arches) create visual depth and rhythm. Use loops in the scene generator:
+
+```c
+// 8 columns spaced 5 units apart along Z axis
+i = 0;
+while (i < 8) {
+    col_z = 10.0 - (double)i * 5.0;
+    cathedral_column(f, -6.0, col_z, heights[i]);
+    i++;
+}
+```
+
+Varying individual column heights within the row breaks monotony and suggests ruin/decay.
+
+## Cathedral Ruins Case Study
+
+### Scene overview
+
+- **File:** `scenes/cathedral_ruins.rt` (307 lines)
+- **Shapes:** ~236 geometric objects
+- **Resolution:** 2560x1440
+- **Render time:** ~20 minutes (multi-threaded, depends on hardware)
+
+### Shape census
+
+| Type | Count | Primary Use |
+|------|-------|-------------|
+| `sp` (sphere) | 68 | Column capitals, rubble, rose window glass, dust motes, candle flames |
+| `bx` (box) | 49 | Walls, rubble blocks, altar, tower battlements, tomb slab |
+| `cy` (cylinder) | 31 | Column shafts, candlesticks, cross, fallen columns, roof rafters |
+| `dk` (disk) | 26 | Column bases, water puddles, candelabra top, font water |
+| `to` (torus) | 20 | Gothic arches, rose window frame, fallen arch fragments |
+| `tr` (triangle) | 16 | Vault fragments, rubble, fallen roof pieces |
+| `sq` (square) | 13 | Floor tiles, stained glass windows, tilted roof panels |
+| `el` (ellipsoid) | 10 | Ivy/vegetation, fallen glass shards |
+| `pl` (plane) | 1 | Ground floor |
+| `pa` (paraboloid) | 1 | Stone font/basin |
+| `co` (cone) | 1 | Tower roof |
+
+### Structural breakdown
+
+| Section | Shapes | Z Range | Description |
+|---------|--------|---------|-------------|
+| Floor & tiles | 5 | all | Ground plane + 4 stone tile squares |
+| Walls | 19 | -30 to 15 | Left/right walls, apse, entrance, transept stubs, buttresses |
+| Left colonnade | 23 | -25 to 10 | 8 columns (cy+dk+sp), 2 broken |
+| Right colonnade | 23 | -25 to 10 | 8 columns, 2 broken differently |
+| Gothic arches | 18 | -28 to 7.5 | 12 side arches + 3 transverse + 1 apse + 2 fallen |
+| Rose window | 22 | -29.3 | 2 torus frames + 12 outer + 6 inner + 1 center glass spheres |
+| Altar area | 12 | -27 to -24 | Table, base, candles, cross, steps |
+| Debris | ~45 | scattered | Fallen columns, rubble boxes/spheres, fragment triangles, capitals |
+| Roof fragments | 18 | 0 to 17 | Vault triangles, tilted panels, floor debris, ridge beams, rafters |
+| Bell tower | 15 | 11 to 23 | Base cylinder, upper section, cone roof, windows, battlements |
+| Dust motes | 5 | 7 to 11 | Tiny transparent spheres in light beams |
+| Water puddles | 8 | 0.02 | Reflective disks on floor |
+| Stained glass | 15 | walls + floor | Transparent windows, floor glass shards, accent spheres |
+| Decorations | 15 | various | Font, tomb, candelabra, ivy |
+
+### Design decisions
+
+**Sandstone palette (R: 170-200, G: 155-185, B: 130-160):** Warm earth tones with a consistent R > G > B bias. Each element varies by 5-10 per channel to prevent flat appearance while maintaining cohesion.
+
+**Column height variation:** Columns at z=-10 (left) and z=0 (right) are broken short. This is controlled by the `left_h[]` and `right_h[]` arrays in the generator. Broken columns omit the capital sphere and have fallen capital spheres placed on the ground nearby.
+
+**Torus for arches:** The torus is the closest available primitive to a semicircular arch. Placed at column-top height (y=14) with axis along Z, each torus spans the gap between adjacent columns. The 20 tori are the scene's biggest performance cost.
+
+**Transparent spheres for rose window:** 12 outer spheres in a circular pattern (computed with sin/cos) with `trans:0.7 ior:1.3` simulate stained glass. Saturated colors (reds, blues, greens, golds) create the jewel-like effect.
+
+## Material Strategy
+
+| Goal | Properties | Example |
+|------|-----------|---------|
+| Polished stone | `spec:0.2` | Column shafts -- subtle sheen on weathered stone |
+| Wet stone / water | `refl:0.5-0.7 spec:0.7-0.9` | Floor puddles -- mirror-like reflections |
+| Stained glass | `trans:0.7-0.85 ior:1.3-1.5` | Rose window, wall windows -- colored light |
+| Metal / gold | `spec:0.6-0.9 refl:0.2-0.3` | Cross, candlesticks -- metallic shine |
+| Pure diffuse | (none) | Rubble, ivy -- no special surface treatment |
+| Atmospheric dust | `trans:0.9 ior:1.0` | Dust motes -- nearly invisible, catches light |
+
+**Guidelines:**
+- Use `spec:` liberally (0.1-0.3) on stone for a wet/polished look
+- Use `refl:` sparingly -- only on puddles and metal. Each reflective surface triggers recursive ray tracing (max depth 4)
+- Combine `trans:` with `ior:` for glass effects. Higher `ior` = more distortion (1.0=air, 1.3=water, 1.5=glass, 1.7=crystal)
+- Don't use materials on rubble/debris -- pure diffuse is faster and looks natural
+
+## Lighting Design
+
+### Warm/cool contrast
+
+The cathedral uses 6 lights with deliberate warm/cool separation:
+
+| Light | Position | Intensity | Color | Purpose |
+|-------|----------|-----------|-------|---------|
+| Main sun | (-3, 25, -5) | 0.9 | 255,240,200 | Primary warm illumination through roof gaps |
+| Secondary sun | (5, 20, 5) | 0.6 | 255,235,190 | Fill warm light from side |
+| Altar glow | (-8, 15, -15) | 0.5 | 255,220,180 | Warm backlight behind altar |
+| Deep apse | (0, 12, -25) | 0.4 | 255,200,150 | Deep warm glow at back wall |
+| Cool fill | (10, 18, -10) | 0.3 | 200,210,255 | Sky-blue through broken wall (contrast) |
+| Ground bounce | (0, 3, 10) | 0.2 | 180,190,210 | Subtle cool ambient from floor |
+
+### Intensity cascade
+
+Lights decrease in intensity from 0.9 to 0.2. The key (brightest) light dominates shadow direction, while fill lights soften shadows without washing them out.
+
+### Ambient ratio
+
+Ambient is set very low (0.08) to preserve dramatic shadows. For gallery scenes, keep ambient at 0.05-0.15. Above 0.2 washes out the scene.
+
+## Color Palette Design
+
+### Base sandstone range
+
+```
+R: 170-200  (warm)
+G: 155-185  (mid)
+B: 130-160  (cool)
+Offset: R > G by ~15, G > B by ~25
+```
+
+### Variation strategy
+
+- **Per-element variation:** Each wall/column/rubble piece varies by 5-10 per channel from neighbors
+- **Height gradient:** Upper elements slightly lighter than ground-level ones
+- **Debris darkening:** Rubble is 10-20 units darker than intact structures
+- **Accent colors:** Only on stained glass (saturated primaries), vegetation (40-80 green range), and metallic objects (gold: 150,120,40)
+
+## Performance Considerations
+
+### Torus cost
+
+The torus intersection requires solving a **quartic equation** (degree 4 polynomial) per ray-torus test. With 20 tori, 6 lights (each casting shadow rays), and 3.7M pixels at 2560x1440, torus shapes dominate render time.
+
+**Optimization options:**
+- Replace decorative tori with cylinder approximations (save ~40% render time)
+- Reduce torus count by removing some side arches
+- Use `--width 1920 --height 1080` for faster iteration
+
+### Shape count impact
+
+| Shapes | Resolution | Approximate Time |
+|--------|-----------|-----------------|
+| ~236 (full) | 2560x1440 | 20-30 min |
+| ~236 (full) | 1920x1080 | 10-15 min |
+| ~236 (full) | 640x360 | 1-3 min |
+
+The BVH acceleration structure helps with large shape counts, but per-intersection cost (especially torus) dominates.
+
+### Shadow rays
+
+Each light source fires a shadow ray per intersection point. With 6 lights, shadow computation is 6x the cost of a single-light scene. Consider reducing to 3-4 lights for faster iteration.
+
+## Scene Improvement Tips
+
+### Adding detail
+- More debris variation: smaller rubble at column bases
+- Moss/lichen: tiny green ellipsoids on north-facing surfaces (wall x=-12)
+- Cobwebs: very thin triangles spanning column gaps
+- Broken furniture: small boxes with wood color (80,50,30) near altar
+
+### Camera angles
+- **Low angle** (y=2): dramatic, emphasizes column height and vault
+- **Bird's eye** (y=25, rot_x=0.2): shows floor plan layout
+- **From altar** looking toward entrance: reverse perspective, entrance light as backlight
+- **Close-up** on rose window (z=-28, y=12): detailed glass pattern
+
+### Material tuning
+- Increase `spec:` on all stone to 0.3 for a rain-wet look
+- Add `refl:0.05` to floor plane for subtle ground reflection
+- Increase rose window `trans:` to 0.9 for more light-passing effect
+
+### Atmospheric effects
+- Add more dust mote spheres (20-30) for visible light shafts
+- Place a semi-transparent plane at y=2 with `trans:0.95` for ground fog
+
+## Using the Scene Generator
+
+### Available presets
+
+| Preset | Description | Key Features |
+|--------|-------------|-------------|
+| `cornell` | Cornell box | Reflective/refractive spheres in enclosed room |
+| `checkerboard` | 5x5 sphere grid | Color palette showcase |
+| `solar` | Solar system | 8 planets orbiting a sun |
+| `spiral` | Spiral spheres | Parametric arrangement |
+| `grid` | Mixed shape grid | Spheres, boxes, cylinders in grid |
+| `scatter` | Random scatter | Mixed shapes, random placement |
+| `reflections` | Reflection showcase | Mirror and colored spheres |
+| `glass` | Glass spheres | Transparent/refractive materials |
+| `cathedral` | Cathedral ruins | 236-shape architectural scene |
+
+### CLI reference
+
+```bash
+# Build the generator
+make gen_scene
+
+# Generate cathedral at default resolution (1920x1080)
+./gen_scene --preset cathedral --output scenes/my_cathedral.rt
+
+# Generate at full resolution with custom seed
+./gen_scene --preset cathedral --width 2560 --height 1440 --seed 42 \
+    --output scenes/cathedral_full.rt
+
+# List all presets
+./gen_scene --list
+```
+
+### Seed behavior
+
+The `--seed` parameter controls randomized debris placement. Structural elements (walls, columns, arches, altar) are deterministic regardless of seed. Only the 30 debris items (15 boxes + 15 spheres) vary with different seeds.
+
+### Adding new presets
+
+1. Add writer helpers for any new shape types needed (see `write_disk`, `write_torus`, etc.)
+2. Write a `gen_yourscene(FILE *f, t_config *cfg)` function
+3. Register in `generate_scene()` dispatcher and `list_presets()`
+4. Rebuild: `make gen_scene`
+
+## Rendering Workflow
+
+### Preview -> Iterate -> Full Render
+
+```bash
+# 1. Quick preview (~1-3 min)
+scripts/render_cathedral.sh --preview
+
+# 2. Edit scene file or adjust generator parameters
+vim scenes/cathedral_ruins_gen.rt
+
+# 3. Medium quality check (~5-10 min)
+scripts/render_cathedral.sh
+
+# 4. Full resolution render (~20-30 min)
+scripts/render_cathedral.sh --full
+
+# 5. Use existing .rt file (skip generation)
+scripts/render_cathedral.sh --scene scenes/cathedral_ruins.rt --full
+```
+
+### Headless rendering
+
+miniRT requires X11 initialization even for `-save` mode. The render script uses `xvfb-run` automatically. For manual headless rendering:
+
+```bash
+Xvfb :99 -screen 0 2560x1440x24 &
+DISPLAY=:99 ./miniRT scene.rt -save --output out.bmp --threads=auto
+```
+
+### Makefile integration
+
+```bash
+# Render with default settings (1280x720)
+make render-cathedral
+
+# Pass custom arguments
+make render-cathedral ARGS="--full"
+make render-cathedral ARGS="--preview --seed 123"
+```
+
+### CLI flags reference
+
+| Flag | Purpose | Default |
+|------|---------|---------|
+| `-save` | Render and save BMP | Required for headless |
+| `--output PATH` | BMP save location | `miniRT.bmp` in CWD |
+| `--threads=auto` | Use all CPU cores | Single-threaded |
+| `--threads N` | Use N threads (max 64) | Single-threaded |
+| `--width N` | Override resolution width | From .rt file |
+| `--height N` | Override resolution height | From .rt file |
+| `--verbose` | Print scene info | Off |
diff --git a/tools/gen_scene.c b/tools/gen_scene.c
index 5e04596..269433b 100644
--- a/tools/gen_scene.c
+++ b/tools/gen_scene.c
@@ -136,6 +136,17 @@ static void write_cylinder(FILE *f, t_vec pos, t_vec ori, double diam,
 		diam, height, col.r, col.g, col.b);
 }
 
+static void write_cylinder_mat(FILE *f, t_vec pos, t_vec ori, double diam,
+							   double height, t_color col, const char *mat)
+{
+	fprintf(f, "cy\t%.2f,%.2f,%.2f\t%.2f,%.2f,%.2f\t%.2f\t%.2f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, ori.x, ori.y, ori.z,
+		diam, height, col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
 static void write_cone(FILE *f, t_vec pos, t_vec ori, double diam,
 						double height, t_color col)
 {
@@ -144,6 +155,17 @@ static void write_cone(FILE *f, t_vec pos, t_vec ori, double diam,
 		diam, height, col.r, col.g, col.b);
 }
 
+static void write_cone_mat(FILE *f, t_vec pos, t_vec ori, double diam,
+						   double height, t_color col, const char *mat)
+{
+	fprintf(f, "co\t%.2f,%.2f,%.2f\t%.2f,%.2f,%.2f\t%.2f\t%.2f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, ori.x, ori.y, ori.z,
+		diam, height, col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
 static void write_square(FILE *f, t_vec pos, t_vec ori, double side,
 						  t_color col)
 {
@@ -152,12 +174,86 @@ static void write_square(FILE *f, t_vec pos, t_vec ori, double side,
 		col.r, col.g, col.b);
 }
 
+static void write_square_mat(FILE *f, t_vec pos, t_vec ori, double side,
+							 t_color col, const char *mat)
+{
+	fprintf(f, "sq\t%.1f,%.1f,%.1f\t%.1f,%.1f,%.1f\t%.0f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, ori.x, ori.y, ori.z, side,
+		col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
 static void write_box(FILE *f, t_vec pos, t_vec size, t_color col)
 {
 	fprintf(f, "bx\t%.2f,%.2f,%.2f\t%.2f,%.2f,%.2f\t%d,%d,%d\n",
 		pos.x, pos.y, pos.z, size.x, size.y, size.z, col.r, col.g, col.b);
 }
 
+static void write_box_mat(FILE *f, t_vec pos, t_vec size, t_color col,
+						   const char *mat)
+{
+	fprintf(f, "bx\t%.2f,%.2f,%.2f\t%.2f,%.2f,%.2f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, size.x, size.y, size.z, col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
+static void write_disk(FILE *f, t_vec pos, t_vec ori, double diam,
+					   t_color col, const char *mat)
+{
+	fprintf(f, "dk\t%.2f,%.2f,%.2f\t%.1f,%.1f,%.1f\t%.2f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, ori.x, ori.y, ori.z, diam,
+		col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
+static void write_torus(FILE *f, t_vec pos, t_vec ori, double major,
+						double minor, t_color col, const char *mat)
+{
+	fprintf(f, "to\t%.2f,%.2f,%.2f\t%.1f,%.1f,%.1f\t%.2f\t%.2f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, ori.x, ori.y, ori.z, major, minor,
+		col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
+static void write_ellipsoid(FILE *f, t_vec pos, t_vec radii, t_color col,
+							const char *mat)
+{
+	fprintf(f, "el\t%.2f,%.2f,%.2f\t%.2f,%.2f,%.2f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, radii.x, radii.y, radii.z,
+		col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
+static void write_triangle(FILE *f, t_vec p1, t_vec p2, t_vec p3,
+						   t_color col)
+{
+	fprintf(f, "tr\t%.1f,%.1f,%.1f\t%.1f,%.1f,%.1f\t%.1f,%.1f,%.1f"
+		"\t%d,%d,%d\n",
+		p1.x, p1.y, p1.z, p2.x, p2.y, p2.z, p3.x, p3.y, p3.z,
+		col.r, col.g, col.b);
+}
+
+static void write_paraboloid(FILE *f, t_vec pos, t_vec ori, double scale,
+							 double height, t_color col, const char *mat)
+{
+	fprintf(f, "pa\t%.2f,%.2f,%.2f\t%.1f,%.1f,%.1f\t%.2f\t%.2f\t%d,%d,%d",
+		pos.x, pos.y, pos.z, ori.x, ori.y, ori.z, scale, height,
+		col.r, col.g, col.b);
+	if (mat)
+		fprintf(f, "\t%s", mat);
+	fprintf(f, "\n");
+}
+
 static void gen_cornell_box(FILE *f, t_config *cfg)
 {
 	write_header(f, cfg);
@@ -454,12 +550,459 @@ static void gen_glass_spheres(FILE *f, t_config *cfg)
 	write_sphere(f, (t_vec){0, 0.6, 6}, 1.2, (t_color){50, 200, 50}, NULL);
 }
 
+/* ---- Cathedral Ruins helpers ---- */
+
+static void cathedral_column(FILE *f, double x, double z, double height)
+{
+	t_color shaft = {200, 185, 160};
+	t_color base = {190, 175, 150};
+
+	write_cylinder_mat(f, (t_vec){x, 0, z}, (t_vec){0, 1, 0},
+		1.4, height, shaft, "spec:0.2");
+	write_disk(f, (t_vec){x, 0.01, z}, (t_vec){0, 1, 0}, 2.4, base, NULL);
+	if (height >= 10.0)
+		write_sphere(f, (t_vec){x, height, z}, 1.6, shaft, "spec:0.2");
+}
+
+static void cathedral_walls(FILE *f)
+{
+	t_color s1 = {190, 175, 150};
+	t_color s2 = {185, 170, 145};
+	t_color s3 = {195, 180, 155};
+
+	write_box(f, (t_vec){-12, 6, -10}, (t_vec){1, 12, 40}, s1);
+	write_box(f, (t_vec){-12, 14, -25}, (t_vec){1, 4, 10}, s2);
+	write_box(f, (t_vec){-12, 3, 8}, (t_vec){1, 6, 8}, s3);
+	write_box(f, (t_vec){12, 7, -10}, (t_vec){1, 14, 40}, s1);
+	write_box(f, (t_vec){12, 16, -5}, (t_vec){1, 2, 15}, s2);
+	write_box(f, (t_vec){0, 7, -30}, (t_vec){10, 14, 1},
+		(t_color){200, 185, 160});
+	write_box(f, (t_vec){-6, 8, -29.5}, (t_vec){2, 16, 1}, s3);
+	write_box(f, (t_vec){6, 8, -29.5}, (t_vec){2, 16, 1}, s3);
+	write_box(f, (t_vec){-9, 5, 15}, (t_vec){3, 10, 1}, s1);
+	write_box(f, (t_vec){9, 5, 15}, (t_vec){3, 10, 1}, s1);
+	write_box(f, (t_vec){0, 15, 15}, (t_vec){12, 3, 1}, s2);
+	write_box(f, (t_vec){-12, 5, -15}, (t_vec){3, 10, 1}, s3);
+	write_box(f, (t_vec){12, 5, -15}, (t_vec){3, 10, 1}, s3);
+	write_box(f, (t_vec){-12, 5, -16}, (t_vec){1, 10, 3}, s1);
+	write_box(f, (t_vec){12, 5, -16}, (t_vec){1, 10, 3}, s1);
+	write_box(f, (t_vec){-12.5, 4, 0}, (t_vec){1.5, 8, 2}, s2);
+	write_box(f, (t_vec){12.5, 4, 0}, (t_vec){1.5, 8, 2}, s2);
+	write_box(f, (t_vec){-12.5, 4, -20}, (t_vec){1.5, 8, 2},
+		(t_color){180, 165, 140});
+	write_box(f, (t_vec){12.5, 4, -20}, (t_vec){1.5, 8, 2},
+		(t_color){180, 165, 140});
+}
+
+static void cathedral_arches(FILE *f)
+{
+	t_color arch = {205, 190, 165};
+	t_color big = {210, 195, 170};
+	double left_z[] = {7.5, 2.5, -2.5, -7.5, -17.5, -22.5};
+	double right_z[] = {7.5, 2.5, -7.5, -10.0, -17.5, -22.5};
+	int i;
+
+	i = 0;
+	while (i < 6)
+	{
+		write_torus(f, (t_vec){-6, 14, left_z[i]}, (t_vec){0, 0, 1},
+			2.5, 0.4, arch, "spec:0.1");
+		write_torus(f, (t_vec){6, 14, right_z[i]}, (t_vec){0, 0, 1},
+			2.5, 0.4, arch, "spec:0.1");
+		i++;
+	}
+	write_torus(f, (t_vec){0, 15, -15}, (t_vec){1, 0, 0}, 6, 0.5, big,
+		"spec:0.15");
+	write_torus(f, (t_vec){0, 15, -5}, (t_vec){1, 0, 0}, 6, 0.5, big,
+		"spec:0.15");
+	write_torus(f, (t_vec){0, 15, 5}, (t_vec){1, 0, 0}, 6, 0.5, big,
+		"spec:0.15");
+	write_torus(f, (t_vec){0, 14, -28}, (t_vec){1, 0, 0}, 5, 0.5, big,
+		"spec:0.15");
+	write_torus(f, (t_vec){-3, 1, -12}, (t_vec){0.3, 0.1, 0.7},
+		2.0, 0.3, (t_color){195, 180, 155}, NULL);
+	write_torus(f, (t_vec){5, 0.5, 3}, (t_vec){0.5, 0.2, 0.6},
+		1.8, 0.3, (t_color){190, 175, 150}, NULL);
+}
+
+static void cathedral_rose_window(FILE *f)
+{
+	t_color outer[] = {
+		{200, 50, 50}, {220, 100, 30}, {230, 200, 50}, {50, 200, 50},
+		{50, 150, 200}, {80, 50, 200}, {150, 50, 200}, {200, 50, 150},
+		{50, 100, 220}, {100, 200, 100}, {220, 180, 50}, {200, 80, 80}};
+	t_color inner[] = {
+		{255, 220, 100}, {100, 180, 255}, {255, 100, 100},
+		{100, 255, 150}, {200, 100, 255}, {255, 200, 100}};
+	double cx = 0.0;
+	double cy = 12.0;
+	double cz = -29.3;
+	double r = 3.2;
+	double ri = 1.3;
+	double angle;
+	int i;
+
+	write_torus(f, (t_vec){0, 12, -29.2}, (t_vec){0, 0, 1}, 3.5, 0.3,
+		(t_color){180, 170, 155}, "spec:0.3");
+	write_torus(f, (t_vec){0, 12, -29.2}, (t_vec){0, 0, 1}, 2.2, 0.2,
+		(t_color){175, 165, 150}, "spec:0.3");
+	i = 0;
+	while (i < 12)
+	{
+		angle = (double)i * PI / 6.0;
+		write_sphere(f, (t_vec){cx + r * sin(angle), cy + r * cos(angle), cz},
+			0.8, outer[i], "trans:0.7 ior:1.3");
+		i++;
+	}
+	i = 0;
+	while (i < 6)
+	{
+		angle = (double)i * PI / 3.0;
+		write_sphere(f, (t_vec){cx + ri * sin(angle), cy + ri * cos(angle),
+			cz}, 0.5, inner[i], "trans:0.8 ior:1.5");
+		i++;
+	}
+	write_sphere(f, (t_vec){0, 12, -29.3}, 0.7,
+		(t_color){255, 255, 220}, "trans:0.85 ior:1.5\tspec:0.5");
+}
+
+static void cathedral_altar(FILE *f)
+{
+	t_color gold = {150, 120, 40};
+
+	write_box_mat(f, (t_vec){0, 1.5, -27}, (t_vec){3, 1.5, 1.5},
+		(t_color){220, 210, 190}, "spec:0.3");
+	write_box(f, (t_vec){0, 0.5, -27}, (t_vec){3.5, 0.5, 2},
+		(t_color){210, 200, 180});
+	write_cylinder_mat(f, (t_vec){-1, 2.25, -27}, (t_vec){0, 1, 0}, 0.15,
+		1.5, (t_color){240, 230, 200}, "spec:0.4");
+	write_sphere(f, (t_vec){-1, 3.75, -27}, 0.25,
+		(t_color){255, 220, 100}, "spec:0.8");
+	write_cylinder_mat(f, (t_vec){1, 2.25, -27}, (t_vec){0, 1, 0}, 0.15,
+		1.5, (t_color){240, 230, 200}, "spec:0.4");
+	write_sphere(f, (t_vec){1, 3.75, -27}, 0.25,
+		(t_color){255, 220, 100}, "spec:0.8");
+	write_cylinder_mat(f, (t_vec){0, 2.25, -27.5}, (t_vec){0, 1, 0}, 0.2,
+		3.0, gold, "spec:0.6 refl:0.2");
+	write_cylinder_mat(f, (t_vec){0, 4.0, -27.5}, (t_vec){1, 0, 0}, 0.2,
+		1.5, gold, "spec:0.6 refl:0.2");
+	write_box(f, (t_vec){0, 0.15, -25.5}, (t_vec){5, 0.15, 1},
+		(t_color){200, 190, 170});
+	write_box(f, (t_vec){0, 0.30, -24.5}, (t_vec){6, 0.15, 1},
+		(t_color){200, 190, 170});
+}
+
+static void cathedral_debris(FILE *f, int seed)
+{
+	int i;
+	double x;
+	double z;
+	double sz;
+	int base_r;
+
+	write_cylinder(f, (t_vec){-4, 0.5, -11}, (t_vec){0.2, 0.1, 0.9},
+		1.3, 3.0, (t_color){195, 180, 155});
+	write_cylinder(f, (t_vec){-3, 0.6, -9}, (t_vec){0.8, 0.1, 0.3},
+		1.3, 2.5, (t_color){200, 185, 160});
+	write_cylinder(f, (t_vec){5, 0.5, 1}, (t_vec){0.1, 0.05, 0.95},
+		1.3, 4.0, (t_color){190, 175, 150});
+	write_cylinder(f, (t_vec){7, 0.6, -18}, (t_vec){0.7, 0.15, 0.5},
+		1.2, 2.0, (t_color){195, 180, 155});
+	srand(seed);
+	i = 0;
+	while (i < 15)
+	{
+		x = randf_range(-9.0, 9.0);
+		z = randf_range(-25.0, 9.0);
+		sz = randf_range(0.4, 1.0);
+		base_r = 175 + (int)(randf() * 15);
+		write_box(f, (t_vec){x, sz / 2.0, z},
+			(t_vec){sz, sz * randf_range(0.5, 1.0), sz * randf_range(0.5, 1.0)},
+			(t_color){base_r, base_r - 15, base_r - 30});
+		i++;
+	}
+	i = 0;
+	while (i < 15)
+	{
+		x = randf_range(-9.0, 9.0);
+		z = randf_range(-25.0, 9.0);
+		sz = randf_range(0.2, 0.4);
+		base_r = 170 + (int)(randf() * 15);
+		write_sphere(f, (t_vec){x, sz / 2.0, z}, sz,
+			(t_color){base_r, base_r - 15, base_r - 30}, NULL);
+		i++;
+	}
+	write_triangle(f, (t_vec){-3.5, 0.1, -10}, (t_vec){-2.5, 0.8, -10.5},
+		(t_vec){-3, 0.1, -11}, (t_color){185, 170, 145});
+	write_triangle(f, (t_vec){4, 0.1, -12}, (t_vec){5, 0.6, -11.5},
+		(t_vec){4.5, 0.1, -12.5}, (t_color){180, 165, 140});
+	write_triangle(f, (t_vec){-7, 0.1, -5}, (t_vec){-6.5, 0.5, -4.5},
+		(t_vec){-7.5, 0.1, -5.5}, (t_color){175, 160, 135});
+	write_triangle(f, (t_vec){7.5, 0.1, -8}, (t_vec){8, 0.7, -7.5},
+		(t_vec){7, 0.1, -8.5}, (t_color){185, 170, 145});
+	write_triangle(f, (t_vec){-1.5, 0.1, 7}, (t_vec){-0.5, 0.6, 6.5},
+		(t_vec){-1, 0.1, 7.5}, (t_color){180, 165, 140});
+	write_triangle(f, (t_vec){2.5, 0.1, 2.5}, (t_vec){3.5, 0.5, 2},
+		(t_vec){3, 0.1, 3}, (t_color){175, 160, 135});
+	write_sphere(f, (t_vec){-6, 0.6, -10.5}, 0.7,
+		(t_color){195, 180, 155}, NULL);
+	write_sphere(f, (t_vec){6, 0.5, 0.5}, 0.6,
+		(t_color){200, 185, 160}, NULL);
+	write_sphere(f, (t_vec){-5.5, 0.4, -20.5}, 0.5,
+		(t_color){190, 175, 150}, NULL);
+	write_sphere(f, (t_vec){6.5, 0.55, -15.5}, 0.65,
+		(t_color){195, 180, 155}, NULL);
+}
+
+static void cathedral_roof(FILE *f)
+{
+	t_color r1 = {175, 165, 145};
+	t_color r2 = {180, 170, 150};
+
+	write_triangle(f, (t_vec){-6, 14, -8}, (t_vec){-2, 10, -6},
+		(t_vec){-6, 14, -4}, r1);
+	write_triangle(f, (t_vec){-2, 10, -6}, (t_vec){2, 10, -6},
+		(t_vec){0, 16, -6}, r2);
+	write_triangle(f, (t_vec){6, 14, -8}, (t_vec){2, 10, -6},
+		(t_vec){6, 14, -4}, r1);
+	write_triangle(f, (t_vec){-6, 15, 2}, (t_vec){-3, 12, 3},
+		(t_vec){-6, 15, 4}, r2);
+	write_triangle(f, (t_vec){6, 15, 2}, (t_vec){3, 12, 3},
+		(t_vec){6, 15, 4}, r1);
+	write_triangle(f, (t_vec){-4, 16, -20}, (t_vec){0, 18, -20},
+		(t_vec){4, 16, -20}, r2);
+	write_square(f, (t_vec){-4, 10, -10}, (t_vec){0.3, 0.7, 0.1}, 4,
+		(t_color){170, 160, 140});
+	write_square(f, (t_vec){5, 11, -3}, (t_vec){0.2, 0.8, 0.3}, 3.5,
+		(t_color){175, 165, 145});
+	write_square(f, (t_vec){-3, 9, 5}, (t_vec){0.4, 0.6, 0.2}, 3,
+		(t_color){165, 155, 135});
+	write_triangle(f, (t_vec){-8, 0.2, -8}, (t_vec){-5, 0.2, -7},
+		(t_vec){-7, 0.2, -10}, (t_color){170, 160, 140});
+	write_triangle(f, (t_vec){3, 0.2, 4}, (t_vec){5, 0.2, 3},
+		(t_vec){4, 0.2, 6}, (t_color){165, 155, 135});
+	write_triangle(f, (t_vec){-2, 0.2, -18}, (t_vec){1, 0.2, -17},
+		(t_vec){-1, 0.2, -20}, (t_color){175, 165, 145});
+	write_triangle(f, (t_vec){7, 0.2, -20}, (t_vec){9, 0.2, -19},
+		(t_vec){8, 0.2, -22}, (t_color){170, 160, 140});
+	write_box(f, (t_vec){0, 17, -5}, (t_vec){0.4, 0.4, 15},
+		(t_color){190, 180, 160});
+	write_box(f, (t_vec){0, 17, -22}, (t_vec){0.4, 0.4, 6},
+		(t_color){185, 175, 155});
+	write_cylinder(f, (t_vec){-3, 15.5, -5}, (t_vec){0.5, 0.3, 0}, 0.3,
+		7.0, (t_color){195, 185, 165});
+	write_cylinder(f, (t_vec){3, 15.5, -5}, (t_vec){0.5, 0.3, 0}, 0.3,
+		7.0, (t_color){195, 185, 165});
+	write_cylinder(f, (t_vec){-3, 15.5, -20}, (t_vec){0.5, 0.3, 0}, 0.3,
+		7.0, (t_color){190, 180, 160});
+}
+
+static void cathedral_tower(FILE *f)
+{
+	write_cylinder_mat(f, (t_vec){-14, 0, 14}, (t_vec){0, 1, 0}, 5.0, 18.0,
+		(t_color){195, 180, 155}, "spec:0.15");
+	write_cylinder_mat(f, (t_vec){-14, 18, 14}, (t_vec){0, 1, 0}, 4.5, 5.0,
+		(t_color){190, 175, 150}, "spec:0.15");
+	write_cone_mat(f, (t_vec){-14, 23, 14}, (t_vec){0, 1, 0}, 5.0, 4.0,
+		(t_color){120, 100, 80}, "spec:0.2");
+	write_box(f, (t_vec){-11.8, 12, 14}, (t_vec){0.5, 2, 1},
+		(t_color){60, 55, 50});
+	write_box(f, (t_vec){-14, 12, 11.8}, (t_vec){1, 2, 0.5},
+		(t_color){60, 55, 50});
+	write_box(f, (t_vec){-11.8, 8, 14}, (t_vec){0.5, 1.5, 0.8},
+		(t_color){65, 60, 55});
+	write_box(f, (t_vec){-14, 8, 11.8}, (t_vec){0.8, 1.5, 0.5},
+		(t_color){65, 60, 55});
+	write_box(f, (t_vec){-12, 23, 14}, (t_vec){0.8, 1, 0.8},
+		(t_color){200, 185, 160});
+	write_box(f, (t_vec){-14, 23, 12}, (t_vec){0.8, 1, 0.8},
+		(t_color){200, 185, 160});
+	write_box(f, (t_vec){-16, 23, 14}, (t_vec){0.8, 1, 0.8},
+		(t_color){195, 180, 155});
+	write_box(f, (t_vec){-14, 23, 16}, (t_vec){0.8, 1, 0.8},
+		(t_color){195, 180, 155});
+	write_cylinder(f, (t_vec){-10, 0.4, 11}, (t_vec){0.6, 0.1, 0.7}, 2.0,
+		3.0, (t_color){190, 175, 150});
+	write_sphere(f, (t_vec){-11, 0.5, 10}, 0.8,
+		(t_color){185, 170, 145}, NULL);
+}
+
+static void cathedral_atmosphere(FILE *f)
+{
+	int i;
+	double dust_x[] = {-2, -1, 0.5, -0.5, 1};
+	double dust_y[] = {8, 10, 9, 11, 7};
+	double dust_z[] = {-4, -3, -5, -6, -2};
+	double dust_sz[] = {0.15, 0.12, 0.10, 0.13, 0.11};
+
+	i = 0;
+	while (i < 5)
+	{
+		write_sphere(f, (t_vec){dust_x[i], dust_y[i], dust_z[i]}, dust_sz[i],
+			(t_color){255, 250, 230}, "trans:0.9 ior:1.0");
+		i++;
+	}
+	write_disk(f, (t_vec){-2, 0.02, -8}, (t_vec){0, 1, 0}, 3.0,
+		(t_color){100, 110, 130}, "refl:0.6 spec:0.8");
+	write_disk(f, (t_vec){3, 0.02, -3}, (t_vec){0, 1, 0}, 2.5,
+		(t_color){95, 105, 125}, "refl:0.6 spec:0.8");
+	write_disk(f, (t_vec){-5, 0.02, 4}, (t_vec){0, 1, 0}, 2.0,
+		(t_color){100, 110, 130}, "refl:0.5 spec:0.7");
+	write_disk(f, (t_vec){7, 0.02, -15}, (t_vec){0, 1, 0}, 1.8,
+		(t_color){95, 105, 125}, "refl:0.5 spec:0.7");
+	write_disk(f, (t_vec){0, 0.02, -18}, (t_vec){0, 1, 0}, 3.5,
+		(t_color){100, 115, 135}, "refl:0.7 spec:0.9");
+	write_disk(f, (t_vec){-8, 0.02, -12}, (t_vec){0, 1, 0}, 1.5,
+		(t_color){90, 100, 120}, "refl:0.5 spec:0.7");
+	write_disk(f, (t_vec){4, 0.02, 8}, (t_vec){0, 1, 0}, 2.2,
+		(t_color){100, 110, 130}, "refl:0.6 spec:0.8");
+	write_disk(f, (t_vec){-1, 0.02, -24}, (t_vec){0, 1, 0}, 2.8,
+		(t_color){95, 110, 130}, "refl:0.65 spec:0.85");
+}
+
+static void cathedral_stained_glass(FILE *f)
+{
+	write_square_mat(f, (t_vec){-11.5, 10, -5}, (t_vec){1, 0, 0}, 2,
+		(t_color){180, 40, 40}, "trans:0.75 ior:1.4");
+	write_square_mat(f, (t_vec){-11.5, 10, -15}, (t_vec){1, 0, 0}, 2,
+		(t_color){40, 80, 180}, "trans:0.75 ior:1.4");
+	write_square_mat(f, (t_vec){11.5, 10, -10}, (t_vec){1, 0, 0}, 2.5,
+		(t_color){40, 160, 80}, "trans:0.7 ior:1.4");
+	write_square_mat(f, (t_vec){11.5, 10, 0}, (t_vec){1, 0, 0}, 2,
+		(t_color){180, 160, 40}, "trans:0.75 ior:1.4");
+	write_square_mat(f, (t_vec){11.5, 10, -20}, (t_vec){1, 0, 0}, 2,
+		(t_color){160, 40, 160}, "trans:0.7 ior:1.4");
+	write_ellipsoid(f, (t_vec){-3, 0.1, -6}, (t_vec){0.5, 0.05, 0.3},
+		(t_color){200, 50, 50}, "trans:0.6 ior:1.3");
+	write_ellipsoid(f, (t_vec){2, 0.1, -14}, (t_vec){0.4, 0.05, 0.4},
+		(t_color){50, 50, 200}, "trans:0.6 ior:1.3");
+	write_ellipsoid(f, (t_vec){-6, 0.1, -19}, (t_vec){0.3, 0.05, 0.5},
+		(t_color){50, 180, 50}, "trans:0.6 ior:1.3");
+	write_ellipsoid(f, (t_vec){4, 0.1, 5}, (t_vec){0.5, 0.05, 0.3},
+		(t_color){200, 180, 50}, "trans:0.6 ior:1.3");
+	write_ellipsoid(f, (t_vec){-1, 0.1, -2}, (t_vec){0.4, 0.05, 0.4},
+		(t_color){180, 50, 180}, "trans:0.6 ior:1.3");
+	write_square_mat(f, (t_vec){0, 11, -29.5}, (t_vec){0, 0, 1}, 3,
+		(t_color){240, 220, 180}, "trans:0.5 ior:1.4 spec:0.3");
+	write_sphere(f, (t_vec){-11.5, 12.5, -5}, 0.5,
+		(t_color){220, 60, 60}, "trans:0.6 ior:1.3");
+	write_sphere(f, (t_vec){-11.5, 12.5, -15}, 0.5,
+		(t_color){60, 100, 220}, "trans:0.6 ior:1.3");
+	write_sphere(f, (t_vec){11.5, 12.5, -10}, 0.5,
+		(t_color){60, 200, 100}, "trans:0.6 ior:1.3");
+	write_sphere(f, (t_vec){11.5, 12.5, 0}, 0.5,
+		(t_color){220, 200, 60}, "trans:0.6 ior:1.3");
+}
+
+static void cathedral_decorations(FILE *f)
+{
+	write_paraboloid(f, (t_vec){-3, 0, 10}, (t_vec){0, 1, 0}, 0.6, 1.5,
+		(t_color){200, 190, 170}, "spec:0.3");
+	write_disk(f, (t_vec){-3, 1.5, 10}, (t_vec){0, 1, 0}, 1.8,
+		(t_color){180, 190, 210}, "refl:0.3 spec:0.5");
+	write_box_mat(f, (t_vec){3, 0.2, -22}, (t_vec){2.5, 0.2, 1.2},
+		(t_color){170, 165, 155}, "spec:0.15");
+	write_sphere(f, (t_vec){3, 0.45, -22}, 0.3,
+		(t_color){160, 155, 145}, NULL);
+	write_cylinder_mat(f, (t_vec){-2, 0, -20}, (t_vec){0, 1, 0}, 0.2, 4.0,
+		(t_color){80, 60, 50}, "spec:0.7 refl:0.3");
+	write_disk(f, (t_vec){-2, 4, -20}, (t_vec){0, 1, 0}, 1.2,
+		(t_color){80, 60, 50}, "spec:0.7 refl:0.3");
+	write_sphere(f, (t_vec){-2, 4.2, -20}, 0.15,
+		(t_color){255, 200, 80}, "spec:0.9");
+	write_sphere(f, (t_vec){-1.5, 4.2, -20}, 0.15,
+		(t_color){255, 200, 80}, "spec:0.9");
+	write_sphere(f, (t_vec){-2.5, 4.2, -20}, 0.15,
+		(t_color){255, 200, 80}, "spec:0.9");
+	write_ellipsoid(f, (t_vec){-11.3, 3, 5}, (t_vec){0.8, 1.5, 0.5},
+		(t_color){40, 80, 30}, NULL);
+	write_ellipsoid(f, (t_vec){-11.3, 5, 4}, (t_vec){0.6, 1.2, 0.4},
+		(t_color){35, 75, 25}, NULL);
+	write_ellipsoid(f, (t_vec){-11.3, 2, 6}, (t_vec){0.7, 1, 0.6},
+		(t_color){45, 85, 35}, NULL);
+	write_ellipsoid(f, (t_vec){11.3, 4, -7}, (t_vec){0.5, 1.3, 0.5},
+		(t_color){40, 80, 30}, NULL);
+	write_ellipsoid(f, (t_vec){11.3, 6, -8}, (t_vec){0.6, 1, 0.4},
+		(t_color){35, 70, 25}, NULL);
+}
+
+static void gen_cathedral_ruins(FILE *f, t_config *cfg)
+{
+	double left_h[] = {14, 14, 14, 14, 8, 14, 5, 14};
+	double right_h[] = {14, 14, 6, 14, 14, 10, 14, 14};
+	double col_z;
+	int i;
+
+	fprintf(f, "R\t%d\t%d\n", cfg->width, cfg->height);
+	fprintf(f, "A\t0.08\t200,190,170\n");
+	fprintf(f, "E\n\n");
+	fprintf(f, "c\t0.0,12.0,25.0\t0.055,0,0\t70\n");
+	fprintf(f, "c\t-4.0,7.0,18.0\t0.04,-0.03,0\t70\n");
+	fprintf(f, "c\t8.0,6.0,-15.0\t0.03,0.3,0\t70\n");
+	fprintf(f, "c\t0.0,2.0,16.0\t0.0,0,0\t70\n\n");
+	write_light(f, (t_vec){-3, 25, -5}, 0.9, (t_color){255, 240, 200});
+	write_light(f, (t_vec){5, 20, 5}, 0.6, (t_color){255, 235, 190});
+	write_light(f, (t_vec){-8, 15, -15}, 0.5, (t_color){255, 220, 180});
+	write_light(f, (t_vec){0, 12, -25}, 0.4, (t_color){255, 200, 150});
+	write_light(f, (t_vec){10, 18, -10}, 0.3, (t_color){200, 210, 255});
+	write_light(f, (t_vec){0, 3, 10}, 0.2, (t_color){180, 190, 210});
+	fprintf(f, "\n");
+	write_plane(f, (t_vec){0, 0, 0}, (t_vec){0, 1, 0},
+		(t_color){170, 160, 140});
+	fprintf(f, "\n");
+	write_square(f, (t_vec){-2, 0.01, -20}, (t_vec){0, 1, 0}, 8,
+		(t_color){140, 130, 110});
+	write_square(f, (t_vec){3, 0.01, -8}, (t_vec){0, 1, 0}, 6,
+		(t_color){155, 145, 125});
+	write_square(f, (t_vec){-5, 0.01, 0}, (t_vec){0, 1, 0}, 5,
+		(t_color){145, 135, 120});
+	write_square(f, (t_vec){6, 0.01, -15}, (t_vec){0, 1, 0}, 7,
+		(t_color){160, 150, 130});
+	fprintf(f, "\n");
+	cathedral_walls(f);
+	fprintf(f, "\n");
+	i = 0;
+	while (i < 8)
+	{
+		col_z = 10.0 - (double)i * 5.0;
+		cathedral_column(f, -6.0, col_z, left_h[i]);
+		i++;
+	}
+	fprintf(f, "\n");
+	i = 0;
+	while (i < 8)
+	{
+		col_z = 10.0 - (double)i * 5.0;
+		cathedral_column(f, 6.0, col_z, right_h[i]);
+		i++;
+	}
+	fprintf(f, "\n");
+	cathedral_arches(f);
+	fprintf(f, "\n");
+	cathedral_rose_window(f);
+	fprintf(f, "\n");
+	cathedral_altar(f);
+	fprintf(f, "\n");
+	cathedral_debris(f, cfg->seed);
+	fprintf(f, "\n");
+	cathedral_roof(f);
+	fprintf(f, "\n");
+	cathedral_tower(f);
+	fprintf(f, "\n");
+	cathedral_atmosphere(f);
+	fprintf(f, "\n");
+	cathedral_stained_glass(f);
+	fprintf(f, "\n");
+	cathedral_decorations(f);
+}
+
 static void print_usage(void)
 {
 	printf("Usage: gen_scene [OPTIONS]\n\n");
 	printf("Options:\n");
 	printf("  --preset NAME    Preset scene (cornell, checkerboard, solar,\n");
-	printf("                   spiral, grid, scatter, reflections, glass)\n");
+	printf("                   spiral, grid, scatter, reflections, glass,\n");
+	printf("                   cathedral)\n");
 	printf("  --width N        Image width (default: 1920)\n");
 	printf("  --height N       Image height (default: 1080)\n");
 	printf("  --objects N      Number of objects (default: 20)\n");
@@ -481,6 +1024,8 @@ static void list_presets(void)
 	printf("  scatter      - Random scatter of mixed shapes\n");
 	printf("  reflections  - Showcase of reflective and refractive materials\n");
 	printf("  glass        - Glass/transparent sphere showcase\n");
+	printf("  cathedral    - Medieval cathedral ruins with columns, arches,"
+		" rose window\n");
 }
 
 static void generate_scene(FILE *f, t_config *cfg)
@@ -501,6 +1046,8 @@ static void generate_scene(FILE *f, t_config *cfg)
 		gen_reflections(f, cfg);
 	else if (strcmp(cfg->preset, "glass") == 0)
 		gen_glass_spheres(f, cfg);
+	else if (strcmp(cfg->preset, "cathedral") == 0)
+		gen_cathedral_ruins(f, cfg);
 	else
 	{
 		fprintf(stderr, "Error: unknown preset '%s'\n", cfg->preset);