Apply Assets

Source: src/mpfb/ui/apply_assets/assetlibrary/ (Root panel: src/mpfb/ui/apply_assets/assetspanel.py)

Parent panel: MPFB_PT_Assets_Panel ("Apply assets")

Overview

The asset library is the primary interface for browsing and applying pre-made assets to a character. It presents installed assets in a scrollable grid with optional thumbnail images, organised by asset type. Each asset type gets its own collapsible sub-panel: clothes, hair, eyes, eyebrows, eyelashes, teeth, tongue, topologies (body proxy meshes), skins, ink layers, and BVH pose files.

Assets are discovered from the user's data directory (configured in MPFB preferences) and from an optional secondary root directory set in the Library Settings panel. Each asset type is scanned from a specific subdirectory — for example, clothes are scanned from clothes/, skins from skins/, and so on.

The library panels are dynamically generated at addon registration time. Rather than defining eleven separate panel classes in Python, assetlibrarypanel.py loops over ASSET_LIBRARY_SECTIONS — a list of dictionaries exported from AssetService — and uses Python's built-in type() to create one bpy.types.Panel subclass per entry. Each generated class is then registered with ClassManager. This means that adding a new asset type to MPFB requires only adding an entry to ASSET_LIBRARY_SECTIONS in assetservice.py.

Equipped items (clothes and body parts already attached to the character) are tracked via the asset_source property stored on each Blender object using GeneralObjectProperties. When a panel draws, it compares each asset's path fragment against the list of equipped sources and highlights matching items in red (Blender's alert colour). An already-equipped asset shows an "Unequip" button instead of "Load".

If no basemesh is present in the scene — or if the basemesh has been baked (has no shape keys) and the bake-override setting is off — clothing and proxy panels will refuse to draw their asset list and instead show a message explaining the problem.

Panels

MPFB_PT_Assets_Panel ("Apply assets")

Attribute	Value
bl_label	"Apply assets"
bl_category	MATERIALSCATEGORY
Base class	Abstract_Panel
Properties prefix	"APAS_"

This is the root panel for the entire Apply Assets category. It lives in src/mpfb/ui/apply_assets/assetspanel.py rather than in the assetlibrary/ subdirectory, but it is the parent of all asset library panels.

On every draw it first checks whether the MakeHuman system assets pack is installed and shows a prominent warning box if it is not (or if the installed version appears to be very old). After the system asset check it draws a "Filter" box containing the filter properties. The pack name filter (packname) is only shown when at least one asset pack with metadata is installed, because without pack metadata the filter has nothing to match against.

All other Apply Assets panels declare bl_parent_id = "MPFB_PT_Assets_Panel", making them nested child panels inside this root.

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Dynamic library panels (_Abstract_Asset_Library_Panel)

The _Abstract_Asset_Library_Panel class in assetlibrarypanel.py defines the common behaviour for all library sub-panels. It is never registered with Blender directly; instead, eleven concrete subclasses are generated from it at module load time by iterating over ASSET_LIBRARY_SECTIONS.

Generated class name	bl_label	asset_subdir	asset_type	Load operator
MPFB_PT_Asset_Library_Panel_proxymeshes	"Topologies library"	proxymeshes	proxy	mpfb.load_library_proxy
MPFB_PT_Asset_Library_Panel_skins	"Skins library"	skins	mhmat	mpfb.load_library_skin
MPFB_PT_Asset_Library_Panel_ink_layers	"Ink layers"	ink_layers	json	mpfb.load_library_ink
MPFB_PT_Asset_Library_Panel_eyes	"Eyes library"	eyes	mhclo	mpfb.load_library_clothes / mpfb.unload_library_clothes
MPFB_PT_Asset_Library_Panel_eyebrows	"Eyebrows library"	eyebrows	mhclo	mpfb.load_library_clothes / mpfb.unload_library_clothes
MPFB_PT_Asset_Library_Panel_eyelashes	"Eyelashes library"	eyelashes	mhclo	mpfb.load_library_clothes / mpfb.unload_library_clothes
MPFB_PT_Asset_Library_Panel_hair	"Hair library"	hair	mhclo	mpfb.load_library_clothes / mpfb.unload_library_clothes
MPFB_PT_Asset_Library_Panel_teeth	"Teeth library"	teeth	mhclo	mpfb.load_library_clothes / mpfb.unload_library_clothes
MPFB_PT_Asset_Library_Panel_tongue	"Tongue library"	tongue	mhclo	mpfb.load_library_clothes / mpfb.unload_library_clothes
MPFB_PT_Asset_Library_Panel_clothes	"Clothes library"	clothes	mhclo	mpfb.load_library_clothes / mpfb.unload_library_clothes
MPFB_PT_Asset_Library_Panel_poses	"Poses library"	poses	bvh	mpfb.load_library_pose

All generated panels share these attributes:

Attribute	Value
bl_space_type	"VIEW_3D"
bl_region_type	"UI"
bl_parent_id	"MPFB_PT_Assets_Panel"
bl_category	CLOTHESCATEGORY
bl_options	{'DEFAULT_CLOSED'}
Base class	bpy.types.Panel (not Abstract_Panel)

The panel draws a responsive grid whose column count is computed from the viewport width (roughly one column per 256 pixels). Each asset in the grid is drawn in a box showing the asset's display name, optionally a thumbnail image (if the asset has a preview registered with Blender's preview system), and either a "Load" or "Unequip" button. An equipped asset's box is drawn with alert = True, which turns it red in Blender's default theme.

The displayed asset list is filtered against the three APAS_ filter properties from the root panel before the grid is rendered.

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MPFB_PT_Asset_Settings_Panel ("Library Settings")

Attribute	Value
bl_label	"Library Settings"
bl_category	CLOTHESCATEGORY
bl_parent_id	"MPFB_PT_Assets_Panel"
bl_options	{'DEFAULT_CLOSED'}
Base class	Abstract_Panel
Properties prefix	"ASLS_"

This panel collects all configuration that controls how assets are loaded. It is divided into several boxes:

• Materials — selects the material type for skins (skin_type), clothes and hair (clothes_type), and eyes (eyes_type), plus the material instances toggle (material_instances).
• Clothes, Bodyparts & Proxies — controls fitting and rigging behaviour: fit_to_body, mask_base_mesh, delete_group, specific_delete_group, set_up_rigging, interpolate_weights, import_subrig, import_weights, add_subdiv_modifier, subdiv_levels, and makeclothes_metadata.
• Install assets — two buttons that open file browsers: "Load pack from zip file" (mpfb.load_pack) and "Install custom target" (mpfb.install_target).
• Asset roots — lets the user override the secondary asset root directory (second_root). Changing this value triggers a full rescan of all asset lists via AssetService.update_all_asset_lists().
• Advanced — the override_bake_check toggle; it unlocks clothing operations on baked (non-deforming) meshes that would otherwise be blocked.

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MPFB_PT_Alternative_Material_Panel ("Alternative materials")

Attribute	Value
bl_label	"Alternative materials"
bl_category	CLOTHESCATEGORY
bl_parent_id	"MPFB_PT_Assets_Panel"
bl_options	{'DEFAULT_CLOSED'}
Base class	Abstract_Panel
Properties prefix	"ALTM_"

This panel allows replacing the material on a piece of equipment with an alternative .mhmat file that ships alongside the asset. It requires an active mesh object that MPFB recognises as a clothes or body-part type. Basemeshes, proxy meshes, and skeleton objects are explicitly excluded.

The panel presents the available materials as a grid of thumbnails, in the same manner as the asset library panels. It reads the asset_source property of the active object, then calls AssetService.alternative_material_tiles_for_asset() to list all .mhmat files belonging to that same asset directory. Each tile shows the material name, a thumbnail, and a Load button (mpfb.load_library_material) which applies that material to the active object.

The first tile represents the material defined by the asset's mhclo file. Loading it restores that material and clears the alternative_material property. The tile matching the object's current alternative_material property is highlighted; when no alternative material is applied, the default tile is the highlighted one.

Materials which do not have a thumbnail of their own get a bundled placeholder image, so that all tiles are drawn at the same size. The filter property narrows the grid by case-insensitive substring match against the material names. It is specific to this panel, and is not related to the shared APAS_ filter on the parent assets panel. The default tile is always shown regardless of the filter.

Operators

MPFB_OT_Load_Library_Clothes_Operator

Attribute	Value
bl_idname	mpfb.load_library_clothes
bl_label	"Load"
bl_options	{'REGISTER', 'UNDO'}
Base class	MpfbOperator

Used by all MHCLO-type library panels (eyes, eyebrows, eyelashes, hair, teeth, tongue, clothes). Steps:

1. Reads all fitting and rigging settings from ASSET_SETTINGS_PROPERTIES via MpfbContext.
2. Identifies the basemesh and rig from the active object or its nearest relatives.
3. Validates preconditions: if fit_to_body, delete_group, or interpolate_weights are enabled, a basemesh must be present; if set_up_rigging is enabled, a rig must be present.
4. Calls HumanService.add_mhclo_asset() with the file path, basemesh, object type, material type, rigging options, and subdivision level.

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MPFB_OT_Unload_Library_Clothes_Operator

Attribute	Value
bl_idname	mpfb.unload_library_clothes
bl_label	"Unequip"
bl_options	{'REGISTER', 'UNDO'}
Base class	MpfbOperator

Removes a previously equipped MHCLO asset from the character. The filepath property receives the asset's path fragment (the value stored in asset_source on the object) rather than the full absolute path. Steps:

1. Identifies the basemesh and rig from the active object.
2. Iterates over all mesh children of the character to find the object whose asset_source matches filepath.
3. Calls HumanService.unload_mhclo_asset() to remove the found object.
4. Re-selects the parent object (rig or basemesh) so the user's selection remains meaningful.

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MPFB_OT_Load_Library_Proxy_Operator

Attribute	Value
bl_idname	mpfb.load_library_proxy
bl_label	"Load"
bl_options	{'REGISTER', 'UNDO'}
Base class	MpfbOperator

Loads a topology proxy (an alternative full-body mesh) from a .mhclo file in the proxymeshes/ subdirectory. Unlike the clothes operator, this one handles proxy loading directly rather than delegating to HumanService.add_mhclo_asset(). Steps:

1. Validates basemesh and rig availability for all enabled settings.
2. Loads the MHCLO file using the Mhclo entity and extracts the mesh.
3. Sets object_type = "Proxymeshes", asset_source, and scale_factor on the new object.
4. Applies smooth shading and creates a MakeSkin material from the MHCLO's material reference.
5. If fit_to_body: calls ClothesService.fit_clothes_to_human() and sets scalings.
6. If set_up_rigging: calls ClothesService.set_up_rigging().
7. If add_subdiv_modifier: adds a Subdivision Surface modifier with render levels from subdiv_levels.
8. If mask_base_mesh: adds a Mask modifier to the basemesh to hide the body where the proxy covers it.
9. If the MHCLO has a UUID and extra vertex groups are registered for that UUID in ALL_EXTRA_GROUPS, those vertex groups are created on the proxy mesh.

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MPFB_OT_Load_Library_Skin_Operator

Attribute	Value
bl_idname	mpfb.load_library_skin
bl_label	"Load"
bl_options	{'REGISTER', 'UNDO'}
Base class	MpfbOperator

Applies a skin material (.mhmat file) to the character's basemesh and optional body proxy. Steps:

1. Reads skin_type and material_instances from ASSET_SETTINGS_PROPERTIES. Note that material_instances is forced to False for LAYERED, GAMEENGINE, and MAKESKIN skin types, since those types do not support multiple material instances.
2. Finds the basemesh and any body proxy from the active object or its relatives.
3. Calls HumanService.set_character_skin() with the .mhmat path, basemesh, optional body proxy, skin type, and material instances flag.
4. Sets the active material slot to the "Body" material on both the basemesh and body proxy (if present).

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MPFB_OT_Load_Library_Material_Operator

Attribute	Value
bl_idname	mpfb.load_library_material
bl_label	"Load"
bl_options	{'REGISTER', 'UNDO'}
Base class	MpfbOperator

Property	Type	Default	Description
filepath	string	""	Full path to the .mhmat file to apply
restore_default	boolean	false	Restore the material defined by the asset's mhclo file, rather than applying filepath

Replaces the material on the active object with the alternative material clicked in the Alternative Materials panel. Steps:

1. If restore_default is set, reads the asset_source property of the object, resolves it to an mhclo file, and reads that file's material reference. Otherwise, uses filepath as given.
2. Removes all existing materials from the object.
3. Creates a new empty material and applies the MakeSkin shader from the .mhmat file.
4. Sets the material's diffuse colour to the standard colour for the object's type (from MaterialService.get_diffuse_colors()).
5. Stores the alternative material fragment in GeneralObjectProperties.alternative_material on the object, or clears that property if the default material was restored.

The operator is cancelled with an error if the material cannot be found, which includes asking for the default material of an object which did not come from the asset library.

Note that the material is always rebuilt as a MakeSkin material. Eyes which were equipped with a procedural material are thus not handled.

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MPFB_OT_Load_Library_Pose_Operator

Attribute	Value
bl_idname	mpfb.load_library_pose
bl_label	"Load Pose"
bl_options	{'REGISTER', 'UNDO'}
Base class	MpfbOperator

Loads a BVH pose file from the Poses library onto the active armature. Warning: This operation changes the bone roll angles of all bones in the rig, making subsequent posing less predictable. Only use it when specifically needed. Steps:

1. Ensures the active object (or a relative) is an armature recognised as an MPFB skeleton.
2. Calls RigService.identify_rig() to determine the rig type. Only rigs that identify as "default" are supported; any other rig type causes an error.
3. Calls AnimationService.import_bvh_file_as_pose() with the armature object and the BVH file path.

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MPFB_OT_Load_Library_Ink_Operator

Attribute	Value
bl_idname	mpfb.load_library_ink
bl_label	"Load"
bl_options	{'REGISTER', 'UNDO'}
Base class	MpfbOperator

Adds an ink layer (a JSON-defined texture overlay, such as tattoos or makeup) to the basemesh's current material. Ink layers are only visible on the basemesh itself — they are not applied to topology proxy meshes. If a proxy is present, a warning is shown. Steps:

1. Finds the basemesh from the active object or its relatives.
2. Gets the basemesh's material and identifies its type via MaterialService.identify_material().
3. Validates that the material type is "makeskin" or "layered_skin". Any other type causes an error.
4. Calls MaterialService.load_ink_layer() with the basemesh and the ink layer JSON file path.
5. Checks whether a body proxy exists and issues a warning if so, because the ink layer will not be visible through the proxy.

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MPFB_OT_Load_Pack_Operator

Attribute	Value
bl_idname	mpfb.load_pack
bl_label	"Load pack from zip file"
bl_options	{'REGISTER'}
Base class	MpfbOperator, ImportHelper
File filter	*.zip

Opens a file browser filtered to .zip files. After the user selects a file, extracts its contents directly into the MPFB user data directory using Python's standard zipfile module. Then calls AssetService.update_all_asset_lists() to refresh the in-memory asset cache so newly installed assets appear without restarting Blender. Advises the user to restart Blender if assets still do not appear immediately.

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MPFB_OT_Install_Target_Operator

Attribute	Value
bl_idname	mpfb.install_target
bl_label	"Install custom target"
bl_options	{'REGISTER'}
Base class	MpfbOperator, ImportHelper
File filter	*.target

Opens a file browser filtered to .target morph target files. After the user selects a file, copies it into the custom/ subdirectory of the MPFB user data directory using shutil.copy(), creating the custom/ directory first if it does not yet exist. Blender must be restarted for the installed target to appear in the custom target list.

Properties

APAS_ — root panel filter properties

Defined inline in assetspanel.py as a SceneConfigSet with prefix "APAS_".

Property	Type	Default	Description
filter	string	""	Only list assets whose display name contains this text (case-insensitive)
packname	string	""	Only list assets belonging to a pack whose name matches this text. Only shown in the UI when at least one asset pack with metadata is installed
only_equipped	boolean	false	When enabled, only assets that are currently equipped on the active character are shown

ASLS_ — library settings properties

Loaded from JSON files in src/mpfb/ui/apply_assets/assetlibrary/properties/ with prefix "ASLS_".

Property	Type	Default	Description
skin_type	enum	MAKESKIN	Material type for skin: GAMEENGINE (simple PBR for export), MAKESKIN (PBR with image textures), ENHANCED (adds procedural aspects), ENHANCED_SSS (Enhanced plus subsurface scattering), LAYERED (most complex multilayered procedural skin)
clothes_type	enum	MAKESKIN	Material type for clothes and hair: GAMEENGINE or MAKESKIN
eyes_type	enum	MAKESKIN	Material type for eyes: GAMEENGINE, MAKESKIN, or PROCEDURAL_EYES (fully procedural with dynamic colour controls)
material_instances	boolean	true	When using Enhanced skin, create material instances for extra vertex groups (e.g. fingernails get a separate material slot alongside the body material)
fit_to_body	boolean	true	Deform the imported clothes to match the character's current body shape
mask_base_mesh	boolean	true	When loading a body proxy, add a Mask modifier to the basemesh to hide it where the proxy covers
delete_group	boolean	true	Create (or update) a delete group on the basemesh that marks the vertices hidden under the clothes
specific_delete_group	boolean	true	Name the delete group after the individual clothing item rather than using the generic name "Delete"
set_up_rigging	boolean	true	Parent the clothes to the rig and add an Armature modifier
interpolate_weights	boolean	true	Derive vertex weights for the clothes by interpolating from the basemesh's weights
import_subrig	boolean	true	Import any sub-rig armature bundled with the clothing object
import_weights	boolean	true	Import weight files bundled with the clothing object (these replace interpolated weights for the groups they cover)
add_subdiv_modifier	boolean	true	Add a Subdivision Surface modifier to the imported object
subdiv_levels	integer	1	Render subdivision levels for the Subdivision Surface modifier
makeclothes_metadata	boolean	false	Store MakeClothes-specific metadata on the object (only needed if the clothes will be re-edited in MakeClothes)
override_bake_check	boolean	false	Allow equipping clothes on baked (non-deforming) basemeshes. By default MPFB blocks this because it often produces unexpected results
second_root	string	""	Override the secondary asset root directory (normally set in the MPFB preferences)
procedural_eyes	boolean	true	Apply a procedural texture to eyes rather than using the standard image-based material

ALTM_ — alternative material properties

Defined inline in alternativematerialpanel.py as a SceneConfigSet with prefix "ALTM_".

Property	Type	Default	Description
filter	string	""	Only list materials with this term in the name. Matched case-insensitively against the material names of the active object's alternative materials

Related

• AssetService — provides ASSET_LIBRARY_SECTIONS, get_asset_list(), update_all_asset_lists(), alternative_materials_for_asset(), and alternative_material_tiles_for_asset()
• HumanService — provides add_mhclo_asset(), unload_mhclo_asset(), and set_character_skin()
• ClothesService — provides fit_clothes_to_human(), set_up_rigging(), and update_delete_group()
• MaterialService — provides load_ink_layer(), identify_material(), and related material utilities
• AnimationService — provides import_bvh_file_as_pose()
• MHCLO file format — the .mhclo format used for clothes and body-part assets