feat(asset-gen): AI Asset Generation — 3D gen/import + 2D image (BYO-key)

.claude/skills/blender-to-unity/SKILL.md

@@ -0,0 +1,66 @@
+---
+name: blender-to-unity
+description: Hand off a model from Blender (via BlenderMCP) into Unity (via MCP for Unity) — export the current Blender model, import it through import_model_file, and place it in the open scene. Use when the user has BlenderMCP and MCP for Unity both connected and wants to bring a Blender model into Unity. Does NOT drive Blender's own generators; BlenderMCP owns how the model got into Blender.
+---
+
+# Blender → Unity Model Handoff
+
+Bring whatever model is currently in Blender into the open Unity scene. The seam is the
+local filesystem: Blender exports a file, Unity imports it. The two servers never talk
+directly.
+
+## Preconditions
+- Both `mcp__blender__*` tools and MCP for Unity tools are connected.
+- A model exists in the Blender scene (confirm with `mcp__blender__get_scene_info` /
+  `mcp__blender__get_object_info`). If empty, stop and tell the user — this skill does not generate models.
+
+## Steps
+1. **Resolve the Unity project path.** Read `mcpforunity://editor/state` for the project
+   root (the editor dataPath's parent). Decide the export format: **FBX by default**
+   (built-in importer, zero extra dependencies). Use glTF/.glb only if glTFast is installed
+   and PBR fidelity matters.
+2. **Export from Blender to a temp path** via `mcp__blender__execute_blender_code`:
+   ```python
+   import bpy, os, tempfile
+   out = os.path.join(tempfile.gettempdir(), "blender_to_unity.fbx")
+   # Export the selection if any, else the whole scene:
+   bpy.ops.export_scene.fbx(filepath=out, use_selection=bool(bpy.context.selected_objects),
+                            apply_unit_scale=True, bake_space_transform=True)
+   print(out)
+   ```
+   (glTF branch: `bpy.ops.export_scene.gltf(filepath=out_glb, export_format='GLB')`.)
+3. **Import into Unity** with `import_model_file`:
+   `import_model_file(source_path=<temp path>, name=<asset name>, target_size=<final size in meters>)`.
+   It returns `{ asset_path, asset_guid }`. Pass `target_size` as the intended final size, but treat
+   it only as a hint: it rescales at import solely when the project's **Auto-normalize** pref is on,
+   and even then is unreliable for Blender FBX (see the **Scale** note). Step 4 does the reliable
+   normalization.
+4. **Place it in the scene, normalized to size.** Ensure the scene has a camera + directional
+   light (`manage_scene` / `manage_gameobject`). Instantiate the model at the chosen position via
+   `manage_gameobject(action="create", prefab_path=<asset_path>, name=<asset name>, position=[x,y,z])`.
+   Then normalize its size deterministically — Blender FBX commonly imports ~100× too large — by
+   measuring the placed model's world bounds and scaling so its largest dimension equals your target
+   size. Run via `execute_code` (substitute your object name and target meters):
+   ```csharp
+   var go = GameObject.Find("<asset name>");
+   var rs = go.GetComponentsInChildren<Renderer>();
+   var b = rs[0].bounds; for (int i = 1; i < rs.Length; i++) b.Encapsulate(rs[i].bounds);
+   float maxDim = Mathf.Max(b.size.x, Mathf.Max(b.size.y, b.size.z));
+   float target = 2f; // intended size in meters
+   if (maxDim > 0.0001f) go.transform.localScale *= target / maxDim;
+   ```
+5. **Verify** with `manage_camera(action="screenshot", include_image=true)` and report the
+   asset path + a screenshot.
+
+## Notes
+- **Scale.** Models from Blender almost always arrive at the wrong scale — its FBX unit handling
+  makes them land ~100× too large in Unity. `import_model_file`'s `target_size` only rescales at
+  import when the project's Auto-normalize pref is enabled, and its importer-level normalization is
+  unreliable for Blender FBX (it can over- or under-shoot, e.g. a `target_size=2` model measured 200 m).
+  The robust fix is the Step 4 measure-bounds-then-set-`localScale` routine, which hits the target
+  size deterministically regardless of the import scale or the Auto-normalize pref.
+- FBX is the default because glTFast is optional in MCP for Unity. If the import errors with
+  "GLB import requires glTFast", re-export as FBX (or install glTFast from the Dependencies tab).
+- Keep one model per handoff; for batches, repeat the loop with distinct names.
+- This skill never sends API keys or file bytes over the MCP bridge — Unity reads the file from disk.
+- `import_model_file` copies only the single source file; for multi-file exports (a text `.gltf` with an external `.bin`, or an `.obj` with a sibling `.mtl`/textures), zip them first and pass the `.zip` — a bare `.gltf`/`.obj` will lose its sidecars.

.claude/skills/blender-to-unity/manual-verify.md

@@ -0,0 +1,14 @@
+# Manual Verify — blender-to-unity
+
+Run against a live Blender (BlenderMCP) + Unity (MCP for Unity) pair.
+
+- [ ] A cube/model exists in Blender (`get_scene_info` shows it).
+- [ ] FBX export writes a non-empty file to the temp path (printed path exists, size > 0).
+- [ ] `import_model_file` returns `success: true` with `asset_path` under `Assets/` and a non-empty `asset_guid`.
+- [ ] The imported model appears in the Project window at `asset_path`.
+- [ ] The model is instantiated in the open scene and visible in a `manage_camera` screenshot.
+- [ ] Scale: after the Step 4 measure-bounds-then-`localScale` routine, the placed model's largest
+      world dimension ≈ the target size (Blender FBX imports ~100× too large until normalized).
+- [ ] glTF path: with glTFast installed, a `.glb` export imports successfully; without it,
+      the error names glTFast/the Dependencies tab (and FBX still works).
+- [ ] No API keys or file bytes appear in any bridge payload (handoff is filesystem-only).

MCPForUnity/Editor/Constants/EditorPrefKeys.cs

@@ -73,5 +73,14 @@ internal static class EditorPrefKeys
         internal const string LogRecordEnabled = "MCPForUnity.LogRecordEnabled";
 
         internal const string ExecuteCodeCompiler = "MCPForUnity.ExecuteCode.Compiler";
+
+        // AI Asset Generation — NON-SECRET config only. Provider API keys live in the OS
+        // secure store (MCPForUnity.Editor.Security.SecureKeyStore), never in EditorPrefs.
+        internal const string AssetGenSelectedModelProvider = "MCPForUnity.AssetGen.ModelProvider";
+        internal const string AssetGenSelectedImageProvider = "MCPForUnity.AssetGen.ImageProvider";
+        internal const string AssetGenDefaultFormat = "MCPForUnity.AssetGen.Format";
+        internal const string AssetGenOutputRoot = "MCPForUnity.AssetGen.OutputRoot";
+        internal const string AssetGenAutoNormalize = "MCPForUnity.AssetGen.AutoNormalize";
+        internal const string AssetGenProviderEnabledPrefix = "MCPForUnity.AssetGen.Enabled.";
     }
 }

MCPForUnity/Editor/Helpers/AssetGenPaths.cs

@@ -0,0 +1,90 @@
+using System;
+using System.IO;
+using UnityEngine;
+
+namespace MCPForUnity.Editor.Helpers
+{
+    /// <summary>
+    /// Project-path conversions shared by the asset-gen import/write code: project-relative
+    /// ("Assets/...") ↔ absolute on-disk paths, with forward-slash normalization for
+    /// cross-platform consistency.
+    /// </summary>
+    public static class AssetGenPaths
+    {
+        /// <summary>Resolve a project-relative ("Assets/...") path to an absolute, forward-slashed path.</summary>
+        public static string ToAbsolute(string projectRelative)
+        {
+            if (string.IsNullOrWhiteSpace(projectRelative)) return projectRelative;
+            string p = projectRelative.Replace('\\', '/');
+            string abs = Path.IsPathRooted(p) ? p : Path.Combine(ProjectRoot(), p);
+            return Path.GetFullPath(abs).Replace('\\', '/');
+        }
+
+        /// <summary>Convert an absolute (or already-relative) path to a project-relative ("Assets/...") path.</summary>
+        public static string ToProjectRelative(string path)
+        {
+            if (TryGetAssetsRelativePath(path, out string rel)) return rel;
+            return path?.Replace('\\', '/');
+        }
+
+        /// <summary>
+        /// Normalize an absolute or "Assets/..." path and verify it resolves inside the project's
+        /// Assets directory. Rejects traversal such as "Assets/../ProjectSettings".
+        /// </summary>
+        public static bool TryGetAssetsRelativePath(string path, out string projectRelative)
+        {
+            projectRelative = null;
+            if (string.IsNullOrWhiteSpace(path)) return false;
+
+            try
+            {
+                string p = path.Replace('\\', '/');
+                string abs;
+                if (p == "Assets" || p.StartsWith("Assets/", StringComparison.Ordinal))
+                {
+                    abs = Path.Combine(ProjectRoot(), p);
+                }
+                else if (Path.IsPathRooted(p))
+                {
+                    abs = p;
+                }
+                else
+                {
+                    return false;
+                }
+
+                string full = Path.GetFullPath(abs).Replace('\\', '/');
+                string dataPath = Path.GetFullPath(Application.dataPath).Replace('\\', '/').TrimEnd('/');
+                if (string.Equals(full, dataPath, StringComparison.Ordinal))
+                {
+                    projectRelative = "Assets";
+                    return true;
+                }
+
+                string prefix = dataPath + "/";
+                if (!full.StartsWith(prefix, StringComparison.Ordinal)) return false;
+
+                projectRelative = "Assets/" + full.Substring(prefix.Length);
+                return true;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        /// <summary>Normalize an Assets folder path, trimming trailing slashes.</summary>
+        public static bool TryGetAssetsFolder(string path, out string projectRelative)
+        {
+            if (!TryGetAssetsRelativePath(path, out projectRelative)) return false;
+            projectRelative = projectRelative.TrimEnd('/');
+            return true;
+        }
+
+        private static string ProjectRoot()
+        {
+            string dataPath = Path.GetFullPath(Application.dataPath).Replace('\\', '/');
+            return dataPath.Substring(0, dataPath.Length - "Assets".Length);
+        }
+    }
+}

MCPForUnity/Editor/Helpers/AssetGenPrefs.cs

@@ -0,0 +1,73 @@
+using MCPForUnity.Editor.Constants;
+using UnityEditor;
+
+namespace MCPForUnity.Editor.Helpers
+{
+    /// <summary>
+    /// Per-user, NON-SECRET configuration for the AI Asset Generation feature.
+    ///
+    /// Provider API keys are never stored here — they live in the OS secure store
+    /// (<see cref="MCPForUnity.Editor.Security.SecureKeyStore"/>). Only UI/behavior
+    /// preferences (selected provider, default format, output folder, normalize toggle,
+    /// per-provider enable flags) are kept in EditorPrefs.
+    /// </summary>
+    public static class AssetGenPrefs
+    {
+        public const string DefaultOutputRoot = "Assets/Generated";
+        public const string DefaultModelProvider = "tripo";
+        public const string DefaultImageProvider = "fal";
+        public const string DefaultFormatValue = "glb";
+
+        public static string ModelProvider
+        {
+            get => EditorPrefs.GetString(EditorPrefKeys.AssetGenSelectedModelProvider, DefaultModelProvider);
+            set => SetOrDelete(EditorPrefKeys.AssetGenSelectedModelProvider, value);
+        }
+
+        public static string ImageProvider
+        {
+            get => EditorPrefs.GetString(EditorPrefKeys.AssetGenSelectedImageProvider, DefaultImageProvider);
+            set => SetOrDelete(EditorPrefKeys.AssetGenSelectedImageProvider, value);
+        }
+
+        public static string DefaultFormat
+        {
+            get => EditorPrefs.GetString(EditorPrefKeys.AssetGenDefaultFormat, DefaultFormatValue);
+            set => SetOrDelete(EditorPrefKeys.AssetGenDefaultFormat, value);
+        }
+
+        /// <summary>Project-relative root under which generated assets are written. Defaults to Assets/Generated.</summary>
+        public static string OutputRoot
+        {
+            get
+            {
+                string v = EditorPrefs.GetString(EditorPrefKeys.AssetGenOutputRoot, string.Empty);
+                return string.IsNullOrWhiteSpace(v) ? DefaultOutputRoot : v;
+            }
+            set => SetOrDelete(EditorPrefKeys.AssetGenOutputRoot, value);
+        }
+
+        /// <summary>When true, imported models are uniformly scaled to a target size on import.</summary>
+        public static bool AutoNormalize
+        {
+            get => EditorPrefs.GetBool(EditorPrefKeys.AssetGenAutoNormalize, true);
+            set => EditorPrefs.SetBool(EditorPrefKeys.AssetGenAutoNormalize, value);
+        }
+
+        public static bool IsProviderEnabled(string providerId) =>
+            !string.IsNullOrEmpty(providerId)
+            && EditorPrefs.GetBool(EditorPrefKeys.AssetGenProviderEnabledPrefix + providerId, false);
+
+        public static void SetProviderEnabled(string providerId, bool enabled)
+        {
+            if (string.IsNullOrEmpty(providerId)) return;
+            EditorPrefs.SetBool(EditorPrefKeys.AssetGenProviderEnabledPrefix + providerId, enabled);
+        }
+
+        private static void SetOrDelete(string key, string value)
+        {
+            if (string.IsNullOrWhiteSpace(value)) EditorPrefs.DeleteKey(key);
+            else EditorPrefs.SetString(key, value.Trim());
+        }
+    }
+}

MCPForUnity/Editor/Helpers/BlenderDetection.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using UnityEngine;
+
+namespace MCPForUnity.Editor.Helpers
+{
+    /// <summary>
+    /// Best-effort detection of a locally installed Blender application, for the Asset Gen tab's
+    /// "Blender → Unity handoff" hint. This finds the Blender APP only — it cannot tell whether the
+    /// BlenderMCP server is configured in the user's AI client (that lives outside Unity).
+    /// </summary>
+    internal static class BlenderDetection
+    {
+        /// <summary>True if a Blender executable is found in a well-known location or on PATH.</summary>
+        public static bool IsInstalled()
+        {
+            try { return DetectIn(CandidatePaths(), File.Exists); }
+            catch { return false; }
+        }
+
+        /// <summary>Pure core: true if <paramref name="exists"/> reports any candidate present. Testable.</summary>
+        internal static bool DetectIn(IEnumerable<string> candidates, Func<string, bool> exists)
+        {
+            if (candidates == null || exists == null) return false;
+            foreach (string c in candidates)
+                if (!string.IsNullOrEmpty(c) && exists(c)) return true;
+            return false;
+        }
+
+        /// <summary>Well-known Blender executable paths for the current platform, plus PATH entries.</summary>
+        internal static IEnumerable<string> CandidatePaths()
+        {
+            var list = new List<string>();
+            bool win = Application.platform == RuntimePlatform.WindowsEditor;
+            string exeName = win ? "blender.exe" : "blender";
+
+            // PATH entries: <dir>/blender(.exe)
+            string pathVar = Environment.GetEnvironmentVariable("PATH") ?? string.Empty;
+            foreach (string dir in pathVar.Split(win ? ';' : ':'))
+                if (!string.IsNullOrWhiteSpace(dir)) list.Add(Path.Combine(dir.Trim(), exeName));
+
+            switch (Application.platform)
+            {
+                case RuntimePlatform.OSXEditor:
+                    list.Add("/Applications/Blender.app/Contents/MacOS/Blender");
+                    string home = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
+                    if (!string.IsNullOrEmpty(home))
+                        list.Add(Path.Combine(home, "Applications/Blender.app/Contents/MacOS/Blender"));
+                    break;
+                case RuntimePlatform.WindowsEditor:
+                    foreach (string pf in new[]
+                             {
+                                 Environment.GetEnvironmentVariable("ProgramFiles"),
+                                 Environment.GetEnvironmentVariable("ProgramFiles(x86)")
+                             })
+                    {
+                        if (string.IsNullOrEmpty(pf)) continue;
+                        string foundation = Path.Combine(pf, "Blender Foundation");
+                        // Blender installs under a version subdir (Blender X.Y); enumerate them.
+                        try
+                        {
+                            if (Directory.Exists(foundation))
+                                foreach (string d in Directory.GetDirectories(foundation))
+                                    list.Add(Path.Combine(d, "blender.exe"));
+                        }
+                        catch { /* unreadable dir; ignore */ }
+                    }
+                    break;
+                case RuntimePlatform.LinuxEditor:
+                    list.Add("/usr/bin/blender");
+                    list.Add("/usr/local/bin/blender");
+                    list.Add("/snap/bin/blender");
+                    list.Add("/var/lib/flatpak/exports/bin/org.blender.Blender");
+                    break;
+            }
+            return list;
+        }
+    }
+}