Generated soul core heart: concept image, preview and prompts

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

art/generated/soul-core-heart/PROMPTS.md

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+# Soul core heart - generated 3D model
+
+Generated on 2026-11-07 with fal.ai. The prompt was written from the game's procedural soul core
+(`draw_throne` and `draw_heart` in `src/render3d.rs`): an obsidian stepped throne, four curved spikes
+with bone tips, iron chains holding a beating crystal heart, and glowing veins.
+
+## Step 1: concept image
+
+- Model: `fal-ai/flux-2-pro`
+- Settings: `image_size: square_hd` (1024x1024), `output_format: png`, `seed: 4711`
+- Result: `concept.png`
+
+Prompt:
+
+```text
+A single dark-fantasy game prop, the "soul core" of an evil dungeon master, isometric three-quarter front view, full object visible and centered, on a plain neutral light-grey studio background, no floor, no scenery, no text.
+
+The prop: a squat stepped pyramid throne of polished black-purple obsidian, four square tiers getting smaller towards the top. At each of the four corners of the base stands a short obsidian pillar, and from each pillar a thick curved obsidian spike rises and leans slightly outwards, its tip capped with yellowed bone. From near the top of every spike a heavy dark iron chain sags inwards and holds a floating heart.
+
+The heart: a faceted crystal heart of deep blood-red ruby, classic heart shape with two rounded lobes and a pointed bottom, hovering about one heart-height above the top tier, held in the air only by the four chains. It glows from inside with hot red-orange light, a few brighter facets catch the light, faint embers drift upwards from it. Thin glowing red veins run across the obsidian steps from below the heart.
+
+Style: stylized low-to-mid poly game asset, chunky readable silhouette, clean shapes, hand-painted textures, like a strategy game building seen from above. Even soft lighting, sharp focus, the whole prop fits in the frame with margin.
+```
+
+## Step 2: image to 3D
+
+- Model: `fal-ai/hunyuan-3d/v3.1/pro/image-to-3d`
+- Input: `concept.png` (front view only, no extra views)
+- Settings: `generate_type: Normal` (textured), `face_count: 100000`, `enable_pbr: false`
+- Result: `soul-core-heart.glb` (about 20 MB, texture baked in), preview `preview.png`
+
+No text prompt is used in this step. The model only sees the concept image.
+
+## Notes
+
+- The throne, the chains and the heart are one fused mesh. The heart cannot be animated on its own;
+  for a beating heart, generate it as a separate model (see below).
+- In the concept the heart rests on a small glowing pedestal instead of floating freely.