Buildings textured by material (stone, iron, wood, cloth); the heart in crystal facets

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

art/generated/textures/materials/PROMPTS.md

@@ -58,6 +58,15 @@ The spine of one old leather-bound book standing upright, filling the whole imag
 An open page of an old spellbook filling the whole image: yellowed parchment with many lines of dark handwritten script, a small drawn magic circle and a red initial letter, in light neutral tones.
 ```
 
+## crystal
+
+```text
+A cut gemstone surface seen close: many sharp triangular and kite-shaped facets with bright edges and darker faces, a few internal glints, in light neutral grey tones.
+```
+
+The soul core's heart (its lobes) and the buildings use the materials too: `props::auto_cube`
+picks one for every box of the buildings by its colour and shape.
+
 ## Processing
 
 `tools/make_material.py` crops (stone and the book lay on white), turns the picture into grey
@@ -74,6 +83,7 @@ python3 $T straw-raw.png straw --crop 0.05,0.05,0.95,0.95
 python3 $T fur-raw.png fur
 python3 $T book-raw.png book --trim --mean 0.75
 python3 $T paper-raw.png paper --color --crop 0.04,0.04,0.96,0.96 --mean 0.8
+python3 $T crystal-raw.png crystal --crop 0.1,0.1,0.9,0.9 --mean 0.75
 ```
 
 Copied to `assets/textures/mat/`.

art/generated/textures/materials/batch.py

@@ -11,6 +11,7 @@ MATS = {
  "fur": "Thick shaggy animal fur with tufts and strands, in light neutral beige-grey tones.",
  "book": "The spine of one old leather-bound book standing upright, filling the whole image: two raised bands near the top and the bottom, "
          "a gilded frame and a short line of golden title letters in the middle, worn leather, in light neutral tones.",
+ "crystal": "A cut gemstone surface seen close: many sharp triangular and kite-shaped facets with bright edges and darker faces, a few internal glints, in light neutral grey tones.",
  "paper": "An open page of an old spellbook filling the whole image: yellowed parchment with many lines of dark handwritten script, "
           "a small drawn magic circle and a red initial letter, in light neutral tones.",
 }