ModelTranslator: 新增 uv_preview.render_uv_png——PIL 绘 UV 线框 PNG

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Tools/ModelTranslator/tests/test_uv_preview.py

@@ -0,0 +1,48 @@
+import os
+import sys
+import tempfile
+import unittest
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+import uv_preview as up
+from PIL import Image
+
+
+class TestToPx(unittest.TestCase):
+    def test_origin_bottom_left_maps_to_bottom_left_pixel(self):
+        # UV(0,0) 原点在左下 -> 图像左下角（x=pad, y=size-pad）
+        x, y = up._to_px(0.0, 0.0, size=100, pad=10)
+        self.assertAlmostEqual(x, 10.0)
+        self.assertAlmostEqual(y, 90.0)
+
+    def test_top_right(self):
+        x, y = up._to_px(1.0, 1.0, size=100, pad=10)
+        self.assertAlmostEqual(x, 90.0)
+        self.assertAlmostEqual(y, 10.0)
+
+
+class TestRenderUvPng(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.mkdtemp()
+
+    def _out(self, name="uv.png"):
+        return os.path.join(self.tmp, name)
+
+    def test_writes_png_of_requested_size(self):
+        polys = [[[0.1, 0.1], [0.4, 0.1], [0.25, 0.4]],
+                 [[0.6, 0.6], [0.9, 0.6], [0.9, 0.9], [0.6, 0.9]]]
+        out = up.render_uv_png(polys, self._out(), size=128)
+        self.assertTrue(os.path.isfile(out))
+        with Image.open(out) as im:
+            self.assertEqual(im.size, (128, 128))
+            self.assertEqual(im.format, "PNG")
+
+    def test_empty_polygons_still_writes_blank(self):
+        out = up.render_uv_png([], self._out("blank.png"), size=64)
+        self.assertTrue(os.path.isfile(out))
+        with Image.open(out) as im:
+            self.assertEqual(im.size, (64, 64))
+
+    def test_degenerate_polygon_skipped_no_crash(self):
+        out = up.render_uv_png([[[0.5, 0.5]]], self._out("deg.png"), size=64)
+        self.assertTrue(os.path.isfile(out))

Tools/ModelTranslator/uv_preview.py

@@ -0,0 +1,31 @@
+"""UV 线框观察图渲染：把 UV 多边形（归一化 0-1 坐标）画成 PNG 供人工查阅。
+在系统 Python（有 Pillow）中运行——Blender 自带 Python 无 PIL，故 UV 几何由
+bl_decimate 导出为 JSON，本模块负责绘制。"""
+from PIL import Image, ImageDraw
+
+
+def _to_px(u, v, size, pad):
+    """UV(0-1, 原点左下) -> 像素(原点左上)，含边距。"""
+    span = size - 2 * pad
+    x = pad + u * span
+    y = pad + (1.0 - v) * span   # V 轴翻转：图像 y 向下
+    return x, y
+
+
+def render_uv_png(polygons, out_png, size=1024, pad=8,
+                  line=(30, 30, 30, 255), fill=(80, 140, 220, 64)):
+    """polygons: [[[u,v], ...], ...] 每个多边形一组 UV 顶点。
+    白底 + 半透明填充 + 深色线框；写 PNG 到 out_png，返回 out_png。"""
+    base = Image.new("RGBA", (size, size), (255, 255, 255, 255))
+    overlay = Image.new("RGBA", (size, size), (0, 0, 0, 0))
+    draw = ImageDraw.Draw(overlay, "RGBA")
+    for poly in polygons:
+        pts = [_to_px(u, v, size, pad) for (u, v) in poly]
+        if len(pts) >= 3:
+            draw.polygon(pts, fill=fill)
+    for poly in polygons:
+        pts = [_to_px(u, v, size, pad) for (u, v) in poly]
+        if len(pts) >= 2:
+            draw.line(pts + pts[:1], fill=line, width=1)
+    Image.alpha_composite(base, overlay).convert("RGB").save(out_png, "PNG")
+    return out_png