Added localEnvUV world node.

Added support for blender's asset browser.
Added some simple utility scripts managing assets.

.gitignore

@@ -1 +1,2 @@
-*.blend1
+*.blend1
+*~

README.md

@@ -2,6 +2,9 @@
 
 A collection of my commonly used blender node groups (shading nodes, geometry nodes, ...)
 
+All the content is prepared to be used with blender's asset browser. Just add the root directory of this repository to
+the asset libraries in the preferences and enjoy all the content.
+
 ## Getting started
 
 To get the nodes either download the respecive blend file directly or download the full repository as a zip file using
@@ -48,6 +51,17 @@ support the asset workflow.
 
 > A volumetric water material.
 
+## World shader nodes
+
+### [LocalEnvUV](worldNodes/halfDomeEnv.blend)
+
+<img src="worldNodes/halfDomeEnv.png" height=200 />
+
+> A node, that calculates environment map UVs for realizing a flat ground on an HDRI based world environment. Just
+> connect this node to your environment image and adjust the size, camera height and the orientation angle to setup the
+> HDRI.
+
+
 ## Geometry nodes
 
 ### [Tissue](geoNodes/tissue.blend) (Blender 3.1)
@@ -126,4 +140,16 @@ The repository also will contain a list of small assets, that can be reused in m
 
 [<img src="assets/ufo.png" height=200/>](assets/ufo.blend)
 
-> A procedural UFO, that utilizes geometry nodes to build the spaceship from a cross section curve. This model additionally is rigged and has  a laser mounted at the bottom.
+> A procedural UFO, that utilizes geometry nodes to build the spaceship from a cross section curve. This model
+> additionally is rigged and has a laser mounted at the bottom.
+
+# Scripts
+
+The [scripts](scripts/) directory contains some little utility scripts, that are useful for asset handling.
+
+* [createAssetCatalogsFromFileTree.py](scripts/createAssetCatalogsFromFileTree.py) takes a directory structure and
+  creates/updates a catalog file for blender's asset browser.
+* [mark_scene_entities_as_asset.sh](scripts/mark_scene_entities_as_asset.sh) is a little script, that takes a scene file
+  and marks the content as assets. It looks into the scene file and if there's only a single object, this objects gets
+  marked as an asset, otherwise all top level collections will be assets. Additionally is finds the right catalog to
+  sort the assets into, ensures there's a preview image and if needed even renders one.

blender_assets.cats.txt

@@ -0,0 +1,12 @@
+# This is an Asset Catalog Definition file for Blender.
+#
+# Empty lines and lines starting with `#` will be ignored.
+# The first non-ignored line should be the version indicator.
+# Other lines are of the format "UUID:catalog/path/for/assets:simple catalog name"
+
+VERSION 1
+
+e35464fe-861b-4038-bf24-25968b09e5e9:assets:
+92f9a51c-b9e6-4acc-a7d7-8e3b070b24a8:geoNodes:
+897ff8e7-4d16-46e8-9ef2-c1a8fa3221a3:shadingNodes:
+db071ab1-33be-4ac0-943f-9012546c3f0d:worldNodes:

scripts/createAssetCatalogsFromFileTree.py

@@ -0,0 +1,59 @@
+#!/usr/bin/python3
+
+import os
+import sys
+import uuid
+import argparse
+import shutil
+
+
+parser = argparse.ArgumentParser(description='Generate an updated blender_assets.cats.txt')
+parser.add_argument('--write', help="If given, update blender's catalog file of the "+
+                                    "current dir. If not, print content to stdout.",
+                    action='store_true')
+args = parser.parse_args()
+
+
+pathsUUIDs = {}
+ignored_dirs = [".git", ".vscode"]
+
+catalog_file = "./blender_assets.cats.txt"
+
+if os.path.exists(catalog_file):
+    with open(catalog_file) as f:
+        for line in f.readlines():
+            if not line.startswith("#") and ":" in line:
+                line_uuid = line.split(":")[0].strip()
+                path = line.split(":")[1].strip()
+                pathsUUIDs[path] = line_uuid
+
+f = None
+if args.write:
+    if os.path.exists(catalog_file):
+        shutil.copyfile(catalog_file, catalog_file+".bak")
+    f = open(catalog_file, "w")
+else:
+    f = sys.stdout
+
+print("# Autogenerated folder based asset catalogs", file=f)
+print("", file=f)
+print("VERSION 1", file=f)
+catalog_paths = []
+for root,dirs,files in os.walk("."):
+    traverse_dirs = []
+    for dir in dirs:
+        if dir in ignored_dirs:
+            continue
+        path = os.path.join(root, dir)
+        if not os.path.exists(os.path.join(path, ".catalogignore")):
+            catalog_path = path.replace("./", "")
+            catalog_paths.append(catalog_path)
+            if not os.path.exists(os.path.join(path, ".nosubcatalogs")):
+                traverse_dirs.append(dir)
+    dirs[:] = traverse_dirs
+catalog_paths.sort()
+for catalog_path in catalog_paths:
+    line_uuid = str(uuid.uuid4())
+    if catalog_path in pathsUUIDs:
+        line_uuid = pathsUUIDs[catalog_path]
+    print(":".join([line_uuid, catalog_path])+":", file=f)

scripts/mark_scene_entities_as_asset.py

@@ -0,0 +1,153 @@
+#!/usr/bin/python3
+
+import os
+import pathlib
+import random
+import math
+from posixpath import relpath
+import tempfile
+
+import bpy
+
+# Config
+
+tags=[""]
+force_preview_update = True
+
+# Nothing to change below
+
+def find_catalog_id():
+    pathsUUIDs = {}
+    blender_catalogs_file = "blender_assets.cats.txt"
+    current_dir = pathlib.Path().absolute()
+    blender_catalogs_dir = None
+    catalog_id = None
+
+    for x in [current_dir, *pathlib.Path(current_dir).parents]:
+        if os.path.exists(os.path.join(x, blender_catalogs_file)):
+            blender_catalogs_dir = x
+            break
+
+    if blender_catalogs_dir is not None:
+        with open(os.path.join(blender_catalogs_dir, blender_catalogs_file)) as f:
+            for line in f.readlines():
+                if not line.startswith("#") and ":" in line:
+                    line_uuid = line.split(":")[0].strip()
+                    path = line.split(":")[1].strip()
+                    pathsUUIDs[path] = line_uuid
+        rel_path = os.path.relpath(current_dir, blender_catalogs_dir)
+        while rel_path != ".":
+            if rel_path in pathsUUIDs:
+                catalog_id = pathsUUIDs[rel_path]
+                break
+            rel_path = str(pathlib.Path(rel_path).parent)
+    return catalog_id
+
+
+def setup_world(scene):
+    # Make sure we have a camera
+    camera_data = bpy.data.cameras.new(name='Camera')
+    camera = bpy.data.objects.new('Camera', camera_data)
+    scene.camera = camera
+    bpy.context.scene.collection.objects.link(camera)
+        
+    # Change Settings
+    camera.rotation_euler = (70/180*math.pi, 0, -20/180*math.pi)
+    # This was needed for very small assets. We could base the clip planes on the scene's bounding box.
+    # camera_data.clip_start = 0.001
+    # camera_data.clip_end = 10
+    scene.render.engine = 'CYCLES'
+    scene.render.resolution_y = 256
+    scene.render.resolution_x = 256
+    scene.render.film_transparent = True
+    scene.render.image_settings.file_format = 'PNG'
+
+    # Setup the environment map
+    scene.world.use_nodes = True
+    world_tree = scene.world.node_tree
+    env_node = world_tree.nodes.new('ShaderNodeTexEnvironment')
+    bg_node = world_tree.nodes['Background']
+    world_tree.links.new(bg_node.inputs['Color'], env_node.outputs['Color'])
+    env_node.image = bpy.data.images.load("/windows/d/3DLibrary/hdri/HDRIHaven/old_depot_4k.hdr")
+
+
+def snapshot(scene, entity, tmpdirname):
+    bpy.ops.object.select_all(action='DESELECT')
+    if entity.rna_type.name == 'Collection':
+        for o in entity.objects:
+            o.select_set(True)
+    else:
+        entity.select_set(True)
+    bpy.ops.view3d.camera_to_view_selected()
+        
+    filename = str(random.randint(0,100000000000))+".png"
+    filepath = str(os.path.abspath(os.path.join(tmpdirname, filename)))
+    scene.render.filepath = filepath
+    
+    #Render File, Mark Asset and Set Image
+    bpy.ops.render.render(write_still = True)
+    
+    return filepath
+
+
+def ensure_preview_image(obj, tmpdirname):
+    preview_filepath = None
+    if obj.preview is None or force_preview_update:
+        exts=['.jpg', '.jpeg', '.png']
+        for ext in exts:
+            check_filepath = bpy.data.filepath.replace(".blend", ext)
+            if os.path.exists(check_filepath):
+                preview_filepath = check_filepath
+        if preview_filepath is None:
+            print("Generating preview image")
+            preview_filepath = snapshot(bpy.context.scene, obj, tmpdirname)
+    return preview_filepath
+
+def mark_entity(obj, preview_filepath, catalog_id):
+    # Mark asset
+    if obj.asset_data is None:
+        print("Marking ", obj)
+        obj.asset_mark()
+    # Set tags
+    for tag in tags:
+        if not tag in obj.asset_data.tags:
+            print("Creating tag ", tag)
+            obj.asset_data.tags.new(tag)
+    # Set preview
+    if obj.preview is None or force_preview_update:
+        override = bpy.context.copy()
+        override['id'] = obj
+        print("Loading preview image: ", preview_filepath)
+        with bpy.context.temp_override(**override):
+            bpy.ops.ed.lib_id_load_custom_preview(filepath=preview_filepath)
+    # Put into right catalog
+    if catalog_id is not None:
+        print("Setting catalog id:", catalog_id)
+        obj.asset_data.catalog_id = catalog_id
+
+
+def collect_asset_entities():
+    asset_entities = []
+    if len(bpy.data.objects)==1:
+        for obj in bpy.data.objects:    
+            if obj.parent is None:
+                asset_entities.append(obj)
+    else:
+        # We are only interested in root collections, which we can find as
+        # children of the scene collection
+        for col in bpy.context.scene.collection.children:
+            asset_entities.append(col)
+    return asset_entities
+
+
+with tempfile.TemporaryDirectory() as tmpdirname:
+    setup_world(bpy.context.scene)
+    preview_file_paths = []
+    for entity in collect_asset_entities():
+        preview_file_paths.append(ensure_preview_image(entity, tmpdirname))
+    #Cleanup
+    bpy.ops.wm.revert_mainfile()
+    # We need to collect the entities twice, because we might revert the blend file inbetween
+    for entity,preview_file_path in zip(collect_asset_entities(), preview_file_paths):
+        mark_entity(entity, preview_file_path, find_catalog_id())
+    bpy.ops.wm.save_mainfile()

scripts/mark_scene_entities_as_asset.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/bash
+
+if [[ $# -ne 1 ]]; then
+    echo "Usage: $0 blend-file"
+    exit 1
+fi
+
+/opt/blender-3.3/blender -b "$1"  -P ~/blender/mark_scene_entities_as_asset.py