SceneConfigSet

Overview

SceneConfigSet is a specialized subclass of BlenderConfigSet that manages configuration settings stored on Blender scenes. It provides convenience features for scene-based storage, which is the most common configuration pattern in MPFB for panel settings and global options.

The primary enhancement over BlenderConfigSet is automatic handling of Blender Context objects. When you pass a bpy.types.Context as the entity reference, SceneConfigSet automatically extracts the context.scene for you. This eliminates boilerplate code in operators and panels where the context is readily available but the scene must be extracted.

SceneConfigSet also provides a convenient factory method from_definitions_in_json_directory() that combines property loading and instantiation in a single call, which is the typical pattern used throughout MPFB's UI modules.

Most MPFB panels use SceneConfigSet to store their settings. When a user adjusts a slider or checkbox in an MPFB panel, the value is written to a property on bpy.context.scene. This means settings persist with the .blend file and can differ between scenes in the same file.

Source

src/mpfb/services/sceneconfigset.py

Dependencies

Dependency	Usage
LogService	Logging via LogService.get_logger("configuration.sceneconfigset")
BlenderConfigSet	Parent class providing core functionality
bpy	bpy.types.Scene as the storage type, bpy.types.Context for automatic extraction

Public API

Constructor

SceneConfigSet(properties, prefix="")

Create a new scene configuration set.

Argument	Type	Default	Description
properties	list[dict]	—	List of property definitions
prefix	str	""	Prefix added after MPFB_

Internally calls BlenderConfigSet.__init__() with bpy.types.Scene as the type.

---

Static Methods

from_definitions_in_json_directory(properties_dir, prefix="")

Create a SceneConfigSet from JSON property definitions in a directory.

Argument	Type	Default	Description
properties_dir	str	—	Directory containing JSON definition files
prefix	str	""	Prefix added after MPFB_

Returns: SceneConfigSet — Configured instance with all properties loaded.

This is the standard factory method used throughout MPFB. It reads all .json files in the directory, parses their property definitions, and creates a ready-to-use SceneConfigSet.

---

Instance Methods

check_and_transform_entity_reference(entity_reference)

Validate and transform the entity reference, extracting the scene from a Context if provided.

Argument	Type	Default	Description
entity_reference	Scene or Context	—	A Blender scene or context

Returns: bpy.types.Scene — The validated scene object.

Raises: ValueError — If the reference is None or not a Scene/Context.

This override allows passing bpy.context directly instead of bpy.context.scene.

---

Inherited Methods

All methods from BlenderConfigSet are available:

• get_value(name, default_value=None, entity_reference=None)
• set_value(name, value, entity_reference=None)
• get_keys()
• has_key(name)
• has_key_with_value(name, entity_reference=None)
• add_property(prop, items_callback=None, override_prefix=None)
• draw_properties(entity_reference, component_to_draw_on, property_names, *, text=None, **kwargs)
• serialize_to_json(json_file_path, entity_reference=None, exclude_keys=None)
• deserialize_from_json(json_file_path, entity_reference=None)
• as_dict(entity_reference=None, exclude_keys=None, json_with_overrides=None)

---

Examples

Creating from JSON Directory

from mpfb.services.sceneconfigset import SceneConfigSet
from mpfb.services.locationservice import LocationService
import os

# Typical MPFB pattern: load properties from a ui subdirectory
props_dir = os.path.join(os.path.dirname(__file__), "properties")
PANEL_PROPERTIES = SceneConfigSet.from_definitions_in_json_directory(
    props_dir,
    prefix="mypanel_"
)

Using Context Instead of Scene

# With SceneConfigSet, you can pass context directly
class MY_OT_Operator(bpy.types.Operator):
    def execute(self, context):
        # These are equivalent:
        value1 = PANEL_PROPERTIES.get_value("setting", entity_reference=context)
        value2 = PANEL_PROPERTIES.get_value("setting", entity_reference=context.scene)

        return {'FINISHED'}

Panel Implementation Pattern

from mpfb.services.sceneconfigset import SceneConfigSet
import os

# Load properties at module level
_PROPS_DIR = os.path.join(os.path.dirname(__file__), "properties")
PANEL_PROPERTIES = SceneConfigSet.from_definitions_in_json_directory(
    _PROPS_DIR,
    prefix="modeling_"
)

class MPFB_PT_ModelingPanel(bpy.types.Panel):
    bl_label = "Modeling"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'
    bl_category = "MPFB"

    def draw(self, context):
        layout = self.layout

        # Draw all panel properties
        PANEL_PROPERTIES.draw_properties(
            context.scene,
            layout,
            ["detail_level", "smoothing_iterations", "preserve_volume"]
        )

Saving and Loading Presets

def save_preset(context, preset_path):
    PANEL_PROPERTIES.serialize_to_json(
        preset_path,
        entity_reference=context.scene,
        exclude_keys=["internal_state"]
    )

def load_preset(context, preset_path):
    PANEL_PROPERTIES.deserialize_from_json(
        preset_path,
        entity_reference=context.scene
    )

Property JSON File Structure

Properties are typically defined in separate JSON files within a properties/ subdirectory:

properties/detail_level.json:

{
    "name": "detail_level",
    "type": "int",
    "description": "Subdivision level for mesh detail",
    "default": 2,
    "min": 0,
    "max": 6,
    "label": "Detail Level"
}

properties/preserve_volume.json:

{
    "name": "preserve_volume",
    "type": "boolean",
    "description": "Maintain mesh volume during smoothing",
    "default": true,
    "label": "Preserve Volume"
}