Update app.py

app.py

@@ -2,6 +2,7 @@ import os
 import logging
 import json
 import tempfile
+import zipfile
 import shapely.geometry
 import pyprt
 import glob
@@ -102,55 +103,61 @@ def _clean_attributes(raw: Dict[str, Any]) -> Dict[str, Any]:
     return cleaned
 
 
-def _download_textures(attrs: Dict[str, Any]) -> tuple:
+def _inject_textures_into_rpk(rpk_path: str, attrs: Dict[str, Any]) -> tuple:
     """
-    Download any texture attributes (values starting with '/texture/') from
-    the Material API, save them to a temporary directory, and replace the
-    attribute values with absolute ``file://`` URIs so PRT can load them
-    from the local filesystem.
-
-    Returns ``(modified_attrs, temp_dir)`` where ``temp_dir`` is the path
-    of the created directory (or ``None`` if nothing was downloaded).
-    The caller **must** remove ``temp_dir`` after generation completes.
-
-    Strategy D: browser-side picks /texture/… path → backend downloads &
-    stores locally → passes absolute path as CGA attribute → PRT resolves
-    from disk → cleanup after generate_model().
+    For any texture attribute (value starts with '/texture/'), download the
+    texture from the Material API and inject it into a temporary copy of the
+    RPK (which is a ZIP file).  The attribute value is replaced with the
+    RPK-relative path so CGA's asset resolution finds it normally.
+
+    Returns ``(rpk_to_use, modified_attrs, temp_dir)``.
+    - ``rpk_to_use``    : path to use for generation (temp copy if textures injected)
+    - ``modified_attrs``: attrs with texture values replaced by RPK-relative paths
+    - ``temp_dir``      : directory to clean up after generation (or ``None``)
+
+    Why RPK injection instead of file:// URIs
+    -----------------------------------------
+    CGA's ``set(material.colormap, WallTexture)`` resolves asset paths relative
+    to the RPK, not the filesystem.  Passing a ``file://`` URI as an attribute
+    value results in "Unknown Texture" because PRT's asset pipeline never sees
+    it.  Injecting the texture directly into the RPK ZIP at a known path lets
+    PRT find it through the normal resolution mechanism.
     """
-    if not MATERIAL_API_BASE:
-        logger.warning("MATERIAL_API_URL not set — texture attributes will not be resolved")
-        return attrs, None
-
     texture_attrs = {
         k: v for k, v in attrs.items()
         if isinstance(v, str) and v.startswith("/texture/")
     }
     if not texture_attrs:
-        return attrs, None
+        return rpk_path, attrs, None
+    if not MATERIAL_API_BASE:
+        logger.warning("MATERIAL_API_URL not set — texture attributes will use CGA defaults")
+        return rpk_path, attrs, None
+
+    temp_dir = tempfile.mkdtemp(prefix="pyprt_rpk_")
+    temp_rpk = os.path.join(temp_dir, os.path.basename(rpk_path))
+    shutil.copy(rpk_path, temp_rpk)
 
-    temp_dir = tempfile.mkdtemp(prefix="pyprt_tex_")
     modified = dict(attrs)
 
     import requests as _requests
     for key, rel_path in texture_attrs.items():
         url = f"{MATERIAL_API_BASE}{rel_path}"
         filename = os.path.basename(rel_path)
-        local_path = os.path.join(temp_dir, filename)
+        # Store under assets/custom/ inside the RPK to avoid collision with existing assets
+        rpk_asset_path = f"assets/custom/{filename}"
         try:
             logger.info(f"Downloading texture '{key}': {url}")
             resp = _requests.get(url, timeout=20)
             resp.raise_for_status()
-            with open(local_path, "wb") as fh:
-                fh.write(resp.content)
-            # PRT accepts file:// URIs for asset resolution
-            file_uri = "file:///" + local_path.replace("\\", "/").lstrip("/")
-            modified[key] = file_uri
-            logger.info(f"Texture saved → {local_path}")
+            with zipfile.ZipFile(temp_rpk, "a", compression=zipfile.ZIP_STORED) as zf:
+                zf.writestr(rpk_asset_path, resp.content)
+            modified[key] = rpk_asset_path
+            logger.info(f"Texture '{key}' injected into RPK as: {rpk_asset_path}")
         except Exception as exc:
-            logger.warning(f"Texture download failed for '{key}' ({url}): {exc}. Using CGA default.")
-            modified.pop(key, None)  # drop so CGA falls back to its default
+            logger.warning(f"Texture injection failed for '{key}' ({url}): {exc}. Using CGA default.")
+            modified.pop(key, None)
 
-    return modified, temp_dir
+    return temp_rpk, modified, temp_dir
 
 
 # RPKs that control report emission via boolean attributes — always force them ON.
@@ -349,8 +356,8 @@ async def generate_model(request: GenerateRequest):
 
         # Sanitise attributes
         clean_attributes = _clean_attributes(request.attributes)
-        # Strategy D: download any Material-API textures to disk, replace attr values
-        clean_attributes, tex_temp_dir = _download_textures(clean_attributes)
+        # Inject any Material-API textures into a temp RPK copy so CGA resolves them
+        rpk_path, clean_attributes, tex_temp_dir = _inject_textures_into_rpk(rpk_path, clean_attributes)
         logger.info(f"Generating with RPK: {rpk_path}")
         logger.info(f"Clean attributes: {clean_attributes}")
 
@@ -536,8 +543,8 @@ async def generate_i3s(request: GenerateRequest):
         
         # Sanitise attributes
         clean_attributes = _clean_attributes(request.attributes)
-        # Strategy D: download any Material-API textures to disk, replace attr values
-        clean_attributes, tex_temp_dir = _download_textures(clean_attributes)
+        # Inject any Material-API textures into a temp RPK copy so CGA resolves them
+        rpk_path, clean_attributes, tex_temp_dir = _inject_textures_into_rpk(rpk_path, clean_attributes)
 
         initial_shape = pyprt.InitialShape(flattened_coords, indices, face_counts)
 
@@ -792,7 +799,8 @@ async def get_model_report(request: GenerateRequest):
 
         # --- Sanitise attributes ---
         clean_attributes = _clean_attributes(request.attributes)
-        clean_attributes, tex_temp_dir = _download_textures(clean_attributes)
+        # Inject any Material-API textures into a temp RPK copy so CGA resolves them
+        rpk_path, clean_attributes, tex_temp_dir = _inject_textures_into_rpk(rpk_path, clean_attributes)
         initial_shape = pyprt.InitialShape(flattened_coords, indices, face_counts)
 
         # --- Run PyEncoder report pass ---