fix(ugc): metal look only from the client's material types

LU Toolbox's metallic table also has colors the client's Materials.xml types
shinyPlastic, such as 131, the grey of many baseplates, so whole baseplates went
into S88_Metal_Model. Metal now comes from the Materials.xml types (shinySteel)
and the settings' colors only; the table still gives colors.

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

dUgcServer/Bricks/UgcPalette.cpp

@@ -171,10 +171,6 @@ namespace UgcPalette {
 		return Transparent().contains(id);
 	}
 
-	bool IsMetallic(uint32_t id) {
-		return Metallic().contains(id);
-	}
-
 	std::optional<glm::vec3> Glow(uint32_t id) {
 		const auto it = GlowColors().find(id);
 		return it != GlowColors().end() ? std::optional(it->second) : std::nullopt;

dUgcServer/Bricks/UgcPalette.h

@@ -18,7 +18,6 @@ namespace UgcPalette {
 	std::optional<glm::vec3> Linear(uint32_t id, bool icon = false);
 
 	bool IsTransparent(uint32_t id);
-	bool IsMetallic(uint32_t id);
 
 	// The glow color (linear) of a glowing material, nullopt for the others
 	std::optional<glm::vec3> Glow(uint32_t id);

dUgcServer/Model/UgcModel.cpp

@@ -204,7 +204,6 @@ namespace UgcModel {
 	eLook LookOf(uint32_t id, const UgcBricks::Material& material, const LookRules& rules) {
 		if (const auto color = rules.colors.find(id); color != rules.colors.end()) return color->second;
 		if (rules.paletteGlow && UgcPalette::Glow(id)) return eLook::GLOW;
-		if (rules.paletteMetallic && UgcPalette::IsMetallic(id)) return eLook::METAL;
 		const auto type = rules.materialTypes.find(material.type);
 		return type != rules.materialTypes.end() ? type->second : eLook::PLASTIC;
 	}

dUgcServer/Model/UgcModel.h

@@ -81,15 +81,15 @@ namespace UgcModel {
 	};
 
 	/**
-	 * Which colors have which look, from the client's data: a Materials.xml MaterialType (brickdb.zip) and LU Toolbox's
+	 * Which colors have which look, from the client's data: a Materials.xml MaterialType (brickdb.zip), LU Toolbox's
-	 * metallic and glow colors (UgcPalette), and colors named in the settings. A named color wins, then glow over metal;
+	 * glow colors (UgcPalette) and colors named in the settings. A named color wins, then glow; transparent bricks are
-	 * transparent bricks are plastic unless their color is glitter.
+	 * plastic unless their color is glitter. LU Toolbox's metallic table is not a look: it has colors the client types
+	 * shinyPlastic (131, 139, 179, 183, 184, ...), plastic in the client's data.
 	 */
 	struct LookRules {
 		std::map<uint32_t, eLook> colors;  // LEGO color ids given a look by the settings (brushed_colors, glitter_colors)
 		std::map<std::string, eLook> materialTypes{ { "shinySteel", eLook::METAL }, { "brushedSteel", eLook::BRUSHED }, { "matteSteel", eLook::BRUSHED },
 			{ "glitter", eLook::GLITTER } };
-		bool paletteMetallic{ true }; // LU Toolbox's Metallic colors (UgcPalette::IsMetallic) are METAL
 		bool paletteGlow{ true };     // its glow colors (UgcPalette::Glow) are GLOW
 	};
 

docs/UgcServer.md

@@ -452,9 +452,11 @@ all of its levels, so each look needs a group of its own.
 | `satin_whiten` | 20 | Percent: how far satin colors are moved towards white (in linear RGB, after the color variation). |
 
 Which color has which look is data, not a list in the code (`UgcModel::LookOf`): glow is LU Toolbox's glow table
-(`UgcPalette::Glow`: 50, 294, 329, 9000-9027), metal is LU Toolbox's metallic table (`UgcPalette::IsMetallic`) plus
+(`UgcPalette::Glow`: 50, 294, 329, 9000-9027), metal is the Materials.xml types above (the clients checked have 8 or
-the Materials.xml types above (the clients checked have 8 or 14 `shinySteel` colors, and 1 or 3 `glitter` ones: 129,
+14 `shinySteel` colors, and 1 or 3 `glitter` ones: 129, 341, 351), glitter is the `glitter` type plus
-341, 351), glitter is the `glitter` type plus `glitter_colors`. Pearl stays plastic (the client has no shader for it).
+`glitter_colors`. LU Toolbox's metallic table only colors bricks, it gives no look: most of it is `shinyPlastic` in the
+client's Materials.xml (131, the grey of many baseplates, is plastic in the client's brick colors too), and it put
+whole baseplates in `S88_Metal_Model`. Pearl stays plastic (the client has no shader for it).
 Only opaque bricks get metal and glow: a transparent glowing color (294 with the brick database palette, alpha 150)
 stays in `S01_Alpha_Model`. Transparent bricks can be glitter (every glitter color the clients have is transparent:
 341 and 351 have alpha 150, 129 is in `transparent_colors`).

tests/dUgcTests/UgcTests.cpp

@@ -476,7 +476,7 @@ TEST(UgcPalette, ColorVariationMatchesLuToolbox) {
 	EXPECT_FALSE(UgcPalette::IsTransparent(21));
 	EXPECT_TRUE(UgcPalette::Glow(9013).has_value());
 	EXPECT_FALSE(UgcPalette::Glow(21).has_value());
-	EXPECT_TRUE(UgcPalette::IsMetallic(309));
+	EXPECT_TRUE(UgcPalette::Linear(309).has_value()); // LU Toolbox's metallic colors are colors, not looks
 	EXPECT_FALSE(UgcPalette::Linear(123456).has_value());
 	EXPECT_NEAR(UgcPalette::LinearToSrgb(*UgcPalette::Linear(1, true)).r, 0.7f, 1e-5f);
 	EXPECT_NEAR(UgcPalette::LinearToSrgb(red).r * 255.0f, 222.0f, 0.5f); // LDD's bright red
@@ -1146,7 +1146,8 @@ TEST(UgcShaders, LooksComeFromTheColorData) {
 	EXPECT_EQ(UgcModel::LookOf(21, plastic, rules), UgcModel::eLook::PLASTIC);
 	EXPECT_EQ(UgcModel::LookOf(5000, steel, rules), UgcModel::eLook::METAL);       // a Materials.xml shinySteel
 	EXPECT_EQ(UgcModel::LookOf(5000, brushed, rules), UgcModel::eLook::BRUSHED);
-	EXPECT_EQ(UgcModel::LookOf(183, plastic, rules), UgcModel::eLook::METAL);      // LU Toolbox's metallic, shinyPlastic in Materials.xml
+	EXPECT_EQ(UgcModel::LookOf(183, plastic, rules), UgcModel::eLook::PLASTIC);    // LU Toolbox's metallic, shinyPlastic in Materials.xml
+	EXPECT_EQ(UgcModel::LookOf(131, plastic, rules), UgcModel::eLook::PLASTIC);    // the same (a grey that is often a whole baseplate)
 	EXPECT_EQ(UgcModel::LookOf(329, plastic, rules), UgcModel::eLook::GLOW);       // LU Toolbox's glow colors
 	EXPECT_EQ(UgcModel::LookOf(50, plastic, rules), UgcModel::eLook::GLOW);
 	EXPECT_EQ(UgcModel::LookOf(9016, plastic, rules), UgcModel::eLook::GLOW);
@@ -1158,13 +1159,12 @@ TEST(UgcShaders, LooksComeFromTheColorData) {
 	EXPECT_EQ(UgcModel::LookOf(150, steel, named), UgcModel::eLook::METAL);
 	UgcModel::LookRules none;
 	none.materialTypes.clear();
-	none.paletteMetallic = false;
 	EXPECT_EQ(UgcModel::LookOf(5000, steel, none), UgcModel::eLook::PLASTIC);
 	EXPECT_EQ(UgcModel::LookOf(150, steel, none), UgcModel::eLook::PLASTIC);
 
 	// Built: opaque vertices get their color's look, transparent bricks none (their glow stays with them)
 	UgcBricks::BrickLibrary library(MakeRes(), 0);
-	library.SetMaterials({ { 5000, brushed } });
+	library.SetMaterials({ { 150, steel }, { 5000, brushed } });
 	std::string error;
 	const auto model = UgcModel::Build(UgcModel::ParseLxfml(R"(<LXFML versionMajor="5"><Bricks>
 		<Brick><Part designID="3001" materials="150"><Bone transformation="1,0,0,0,1,0,0,0,1,0,0,0"/></Part></Brick>
@@ -1189,6 +1189,7 @@ TEST(UgcShaders, LooksComeFromTheColorData) {
 
 TEST(UgcShaders, WritesAGroupPerLookWithEveryLevel) {
 	UgcBricks::BrickLibrary library(MakeRes(), 0);
+	library.SetMaterials({ { 150, { 152, 155, 153, 255, "shinySteel" } } }); // the client's Materials.xml entry
 	auto settings = SmallSettings();
 	settings.build.colorVariation = 0.0f;
 	settings.shaders.metal = 88;