Improve the material preview in the inspector

Author: ydeltastar

core/config/project_settings.cpp

@@ -1703,6 +1703,27 @@ ProjectSettings::ProjectSettings() {
 	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "rendering/textures/canvas_textures/default_texture_filter", PROPERTY_HINT_ENUM, "Nearest,Linear,Linear Mipmap,Nearest Mipmap"), 1);
 	GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "rendering/textures/canvas_textures/default_texture_repeat", PROPERTY_HINT_ENUM, "Disable,Enable,Mirror"), 0);
 
+	List<String> exts;
+	ResourceLoader::get_recognized_extensions_for_type("Environment", &exts);
+	String ext_hint;
+	for (const String &E : exts) {
+		if (!ext_hint.is_empty()) {
+			ext_hint += ",";
+		}
+		ext_hint += "*." + E;
+	}
+	GLOBAL_DEF(PropertyInfo(Variant::STRING, "editor/3d/preview_environment", PROPERTY_HINT_FILE, ext_hint), "");
+	List<String> mat_exts;
+	ResourceLoader::get_recognized_extensions_for_type("BaseMaterial3D", &mat_exts);
+	String mat_ext_hint;
+	for (const String &E : mat_exts) {
+		if (!mat_ext_hint.is_empty()) {
+			mat_ext_hint += ",";
+		}
+		mat_ext_hint += "*." + E;
+	}
+	GLOBAL_DEF(PropertyInfo(Variant::STRING, "editor/3d/preview_floor_material", PROPERTY_HINT_FILE, mat_ext_hint), "");
+
 	GLOBAL_DEF("collada/use_ambient", false);
 
 	// Input settings

doc/classes/ProjectSettings.xml

@@ -1072,6 +1072,12 @@
 			Directory that contains the [code].sln[/code] file. By default, the [code].sln[/code] files is in the root of the project directory, next to the [code]project.godot[/code] and [code].csproj[/code] files.
 			Changing this value allows setting up a multi-project scenario where there are multiple [code].csproj[/code]. Keep in mind that the Godot project is considered one of the C# projects in the workspace and it's root directory should contain the [code]project.godot[/code] and [code].csproj[/code] next to each other.
 		</member>
+		<member name="editor/3d/preview_environment" type="String" setter="" getter="" default="&quot;&quot;">
+			Path to the [Environment] resource that will be used in the Inspector's material preview. If this is not set, a default environment will be used instead.
+		</member>
+		<member name="editor/3d/preview_floor_material" type="String" setter="" getter="" default="&quot;&quot;">
+			Path to the [BaseMaterial3D] resource that will be assigned to the floor of the Inspector's material preview. If this is not set, a default material will be used instead.
+		</member>
 		<member name="editor/export/convert_text_resources_to_binary" type="bool" setter="" getter="" default="true">
 			If [code]true[/code], text resource ([code]tres[/code]) and text scene ([code]tscn[/code]) files are converted to their corresponding binary format on export. This decreases file sizes and speeds up loading slightly.
 			[b]Note:[/b] Because a resource's file extension may change in an exported project, it is heavily recommended to use [method @GDScript.load] or [ResourceLoader] instead of [FileAccess] to load resources dynamically.