Terrain: winter preset for snowy mountains with trees

app/llms.txt

@@ -202,8 +202,8 @@ Request (JSON; only the ground and a prompt are required):
   in fixed directions, so describe surfaces, not structures with a direction: "packed gravel", not "a lane with two
   ruts and a grass strip" (paths get an even surface automatically). "from_above" (optional) says how a layer looks
   in the colour map when that differs from its close-up; forests and woods default to their tree crowns. Presets
-  (when layers is omitted, chosen from the prompt's words): alpine, temperate, desert, arctic, volcanic (GET /api
-  lists them).
+  (when layers is omitted, chosen from the prompt's words): alpine, temperate, desert, arctic, winter, volcanic (GET
+  /api lists them).
 - uv: planar (default: terrain.glb gets top-down UVs) | keep (the colour map is baked into your own UVs).
 - backend: qwen-turbo (default) | qwen-space | mock (free dry run). Cost: layers + 1 + tiles images (2048: about
   15 images, ~2 min of GPU quota and ~2-3 min in all; 4096: ~31 images).

projtex/terrain.py

@@ -805,6 +805,17 @@ PRESETS: dict[str, dict] = {
                     "where": {"slope": [22, None], "curvature": [0.1, None]}, "tile_m": 4},
                    {"name": "rock", "prompt": "dark grey rock with snow caught in the cracks",
                     "where": {"slope": [34, None]}, "tile_m": 6}]},
+    "winter": {"about": "snowy mountains: deep snow, snow-dusted conifer forest on the lower slopes, scree and dark "
+                        "rock on the steep faces",
+               "layers": [
+                   {"name": "snow", "prompt": "deep white snow with soft wind ripples", "tile_m": 6},
+                   {"name": "forest", "prompt": "snow on a conifer forest floor with fallen needles and small twigs",
+                    "from_above": "snow-dusted dark green conifer tree crowns",
+                    "where": {"height": [None, 0.5], "slope": [8, 36]}, "tile_m": 4},
+                   {"name": "scree", "prompt": "grey scree half buried in snow",
+                    "where": {"slope": [26, None], "curvature": [0.15, None], "height": [0.2, None]}, "tile_m": 4},
+                   {"name": "rock", "prompt": "dark grey rock with snow caught in the cracks",
+                    "where": {"slope": [36, None]}, "tile_m": 6}]},
     "volcanic": {"about": "volcanic land: ash plains, black lava flows, basalt cliffs, moss",
                  "layers": [
                      {"name": "ash", "prompt": "dark grey volcanic ash and fine cinders", "tile_m": 4},
@@ -823,8 +834,15 @@ MAX_LAYERS = 8
 
 
 def choose_preset(prompt: str) -> str:
+    """The preset a prompt's words point to. A snowy mountain with trees (a ski area in winter) is "winter": the
+    arctic preset has no forest and paints its stream beds as blue ice (round 29)."""
     import re
 
+    if (re.search(r"\b(?:mid)?winter|\bsnowy|\bsnow-covered|\bski(?:s|ing)?\b", prompt or "", re.I)
+            and re.search(r"\b(?:alpine|alps|mountains?|peaks?|ski|forests?|woods|spruces?|pines?|firs?|conifers?|trees)\b",
+                          prompt or "", re.I)
+            and not re.search(r"arctic|antarctic|polar|tundra|glacier", prompt or "", re.I)):
+        return "winter"
     for name, pat in _PRESET_WORDS:
         if re.search(pat, prompt or "", re.I):
             return name