Sprint 4: badge_with_text deterministic template

Adds a badge_with_text template that computes text size and z-position
deterministically so text and badge never drift regardless of LLM output.

- scene.py: _template_badge_with_text() builds ExtrudeNode + Text3DNode with
font-width-aware text_size and fixed z=0.15 front-face offset; registered
in TEMPLATES
- app.py: _detect_badge_template() regex routes "a <shape> badge with text X"
prompts to the template, bypassing the LLM entirely
- llm.py: SYSTEM documents badge_with_text template format; FEWSHOT updated to
use template JSON for both "star badge PRO" and new "shield badge NEW" examples

app.py

@@ -10,6 +10,7 @@ from __future__ import annotations
 import json
 import logging
 import os
+import re
 
 import gradio as gr
 
@@ -53,6 +54,22 @@ EXAMPLES = [
 
 _NESTED_SPHERE_PATTERNS = ("wireframe sphere inside", "sphere inside", "nested sphere")
 
+# Detect "a <shape> badge with the text <WORD>" patterns deterministically.
+# Group 1 = shape, group 2 = text word (converted to uppercase).
+_BADGE_TEXT_RE = re.compile(
+    r'\b(star|shield|hexagon|badge|heart)\b.{0,60}'
+    r'\b(?:text|saying|word|label)\b\s*["\']?([A-Za-z0-9]{1,20})["\']?',
+    re.IGNORECASE,
+)
+
+
+def _detect_badge_template(prompt: str):
+    """Return (shape, text) if prompt matches badge-with-text, else (None, None)."""
+    m = _BADGE_TEXT_RE.search(prompt)
+    if m:
+        return m.group(1).lower(), m.group(2).upper()
+    return None, None
+
 
 def generate(prompt: str, glow: bool, glow_strength: float, style: str, motion: str,
              lighting: str, shadows: bool):
@@ -64,7 +81,24 @@ def generate(prompt: str, glow: bool, glow_strength: float, style: str, motion:
 
     lo = prompt.lower()
 
-    if any(pat in lo for pat in _NESTED_SPHERE_PATTERNS):
+    badge_shape, badge_text = _detect_badge_template(lo)
+    if badge_shape and badge_text:
+        scene = build_scene({
+            "background": "#0d1117",
+            "template": {
+                "name": "badge_with_text",
+                "shape": badge_shape,
+                "text": badge_text,
+            },
+            "lights": [
+                {"type": "ambient", "intensity": 0.4},
+                {"type": "directional", "color": "#ffffff", "intensity": 2.0,
+                 "position": [4, 6, 4]},
+            ],
+            "animation": {"type": "rotate", "speed": 0.5, "axis": "y"},
+        })
+        note = "Template (badge with text)."
+    elif any(pat in lo for pat in _NESTED_SPHERE_PATTERNS):
         scene = build_scene({
             "background": "#0b0e14",
             "objects": [o.model_dump() for o in TEMPLATES["nested_spheres"]({})],

llm.py

@@ -76,7 +76,23 @@ For 3D text (words, numbers, short labels) use a TEXT3D object (Latin chars only
   "position": [x, y, z]
 }
 Use text3d for: single words, numbers, initials, short labels (max 2 text objects per scene).
-Combine text3d with extrude for badges with text (position text slightly in front: z+0.3).
+For a badge/emblem with text on it, use the badge_with_text TEMPLATE — never place text3d manually on an extrude:
+{
+  "background": "#0d1117",
+  "template": {
+    "name": "badge_with_text",
+    "shape": "star|shield|hexagon|badge|heart",
+    "text": "WORD",
+    "color_badge": "#RRGGBB",
+    "color_text": "#RRGGBB",
+    "metalness": 0.0-1.0,
+    "roughness": 0.0-1.0,
+    "preset_badge": "gold|chrome|glass|neon|matte|plastic"
+  },
+  "lights": [...],
+  "animation": {...}
+}
+The template positions and scales the text automatically — never set text position or size.
 
 Material preset notes:
 - gold/chrome: use for shiny metallic looks; color overrides the base hue
@@ -313,25 +329,39 @@ FEWSHOT = [
     {"role": "user", "content": "a star badge with the text PRO"},
     {"role": "assistant", "content": json.dumps({
         "background": "#0d1117",
-        "objects": [
-            {
-                "type": "extrude", "shape": "star", "depth": 0.15, "bevel": True,
-                "color": "#3a6bc4", "metalness": 0.7, "roughness": 0.2,
-                "position": [0, 0, 0],
-            },
-            {
-                "type": "text3d", "text": "PRO",
-                "size": 0.35, "depth": 0.1, "bevel": True,
-                "color": "#ffffff", "metalness": 0.1, "roughness": 0.4,
-                "position": [0, -0.15, 0.3],
-            },
-        ],
+        "template": {
+            "name": "badge_with_text",
+            "shape": "star",
+            "text": "PRO",
+            "color_badge": "#3a6bc4",
+            "color_text": "#ffffff",
+            "metalness": 0.7,
+            "roughness": 0.2,
+        },
         "lights": [
             {"type": "ambient", "intensity": 0.4},
             {"type": "directional", "color": "#ffffff", "intensity": 2.0, "position": [3, 5, 4]},
         ],
         "animation": {"type": "rotate", "speed": 0.5, "axis": "y"},
     })},
+    {"role": "user", "content": "a shield badge with the text NEW"},
+    {"role": "assistant", "content": json.dumps({
+        "background": "#0d1117",
+        "template": {
+            "name": "badge_with_text",
+            "shape": "shield",
+            "text": "NEW",
+            "color_badge": "#22aa66",
+            "color_text": "#ffffff",
+            "metalness": 0.5,
+            "roughness": 0.3,
+        },
+        "lights": [
+            {"type": "ambient", "intensity": 0.4},
+            {"type": "directional", "color": "#ffffff", "intensity": 2.0, "position": [4, 6, 4]},
+        ],
+        "animation": {"type": "rotate", "speed": 0.5, "axis": "y"},
+    })},
 ]
 
 _tok = None

scene.py

@@ -591,11 +591,70 @@ def _template_nested_spheres(params: Dict[str, Any]) -> List[Obj]:
     ]
 
 
+# Per-shape: safe text face width (world units after normalization to 1.5)
+# and a small y nudge so text sits in the visual body, not the tapered parts.
+_BADGE_SHAPE_PARAMS: Dict[str, Dict[str, float]] = {
+    "star":    {"safe_w": 0.85, "text_y": 0.0},
+    "heart":   {"safe_w": 0.65, "text_y": 0.2},
+    "hexagon": {"safe_w": 1.1,  "text_y": 0.0},
+    "badge":   {"safe_w": 1.2,  "text_y": 0.0},
+    "shield":  {"safe_w": 0.9,  "text_y": 0.1},
+}
+
+_CHAR_W = 0.65  # helvetiker average char width per size=1.0 unit
+
+
+def _template_badge_with_text(params: Dict[str, Any]) -> List[Any]:
+    """Deterministic badge+text: model supplies shape/text/colors; compiler sets layout."""
+    shape = str(params.get("shape", "star")).lower()
+    if shape not in EXTRUDE_SHAPES:
+        shape = "star"
+
+    text_raw = str(params.get("text", "TEXT"))
+    text = "".join(c for c in text_raw if c.isprintable() and ord(c) < 128)[:24].strip() or "TEXT"
+
+    color_badge  = _sanitize_color(str(params.get("color_badge", "#3a6bc4")),   "#3a6bc4")
+    color_text   = _sanitize_color(str(params.get("color_text",  "#ffffff")),   "#ffffff")
+    badge_metal  = _clamp(float(params.get("metalness", 0.5)),  0.0, 1.0)
+    badge_rough  = _clamp(float(params.get("roughness", 0.25)), 0.0, 1.0)
+
+    preset_badge = str(params.get("preset_badge", "")) or None
+    if preset_badge not in PRESET_NAMES:
+        preset_badge = None
+    preset_text = str(params.get("preset_text", "")) or None
+    if preset_text not in PRESET_NAMES:
+        preset_text = None
+
+    sp = _BADGE_SHAPE_PARAMS.get(shape, {"safe_w": 1.0, "text_y": 0.0})
+
+    # Scale text so it fills ~80 % of the badge face width
+    text_size = round(
+        _clamp(sp["safe_w"] * 0.8 / (max(1, len(text)) * _CHAR_W), 0.12, 0.55), 3
+    )
+
+    return [
+        ExtrudeNode(
+            shape=shape, depth=0.15, bevel=True,
+            color=color_badge, preset=preset_badge,
+            metalness=badge_metal, roughness=badge_rough,
+            emissive="#000000", position=[0.0, 0.0, 0.0],
+        ),
+        Text3DNode(
+            text=text, size=text_size, depth=0.06, bevel=True,
+            color=color_text, preset=preset_text,
+            metalness=0.1, roughness=0.4, emissive="#000000",
+            # z=0.15 always clears the badge front face (badge front ≈ 0.05–0.07 after scale)
+            position=[0.0, sp["text_y"], 0.15],
+        ),
+    ]
+
+
 TEMPLATES: Dict[str, Any] = {
-    "burger":         _template_burger,
-    "snowman":        _template_snowman,
-    "tree":           _template_tree,
-    "nested_spheres": _template_nested_spheres,
+    "burger":           _template_burger,
+    "snowman":          _template_snowman,
+    "tree":             _template_tree,
+    "nested_spheres":   _template_nested_spheres,
+    "badge_with_text":  _template_badge_with_text,
 }