Attachment Points

An attachment point is a named anchor on a rig: a bone plus a placement, carrying tags that attachments target. Points decouple attachments from body layouts. An “ears” attachment targets the ear tag, and each rig decides where its ears actually are.

Path: data/<namespace>/attachment_point/<id>.json

Schema: townstead:attachment_point/v1

Fields

Field	Type	Required	Notes
bone	string	no	The model bone the point rides. Defaults to body.
offset	[x, y, z]	no	Placement in model pixels, relative to the bone.
rotation	[x, y, z]	no	Base orientation applied to anything anchored here (ZYX degrees).
mirror	bool	no	Render anchored geometry mirrored across X. One authored ear fits both sides.
rig	string	no	Scope the point to one rig id. Empty means universal.
tags	list	no	The tags attachments target (ear, tail_root, and so on).

Resolution Rules

When a definition targets a tag, it renders one instance at every point carrying that tag. This is how a single ear definition fills both ears: the left and right ear points both carry the ear tag, and the right one is a mirror point.

Rig scoping refines placement per body. A point with "rig": "my_pack:spider" only resolves on that rig, and when any rig-scoped point carries a tag, the rig’s own placement replaces the universal set for that tag entirely. A spider puts its ear points where spider anatomy wants them, not where the humanoid head is.

For example, a universal ear point may serve every rig. A spider pack can replace the complete set for only its rig:

{
  "schema": "townstead:attachment_point/v1",
  "rig": "my_pack:spider",
  "bone": "cephalothorax",
  "offset": [3, 1, -4],
  "rotation": [0, 25, 0],
  "tags": ["ear"]
}

On my_pack:spider, { "tag": "ear" } now uses only spider-scoped ear points; it does not also render on the universal ears. Other rigs keep the universal set. Add a second spider point if the spider should receive a pair.

Targeting point instead of tag anchors to exactly one named point. Targeting a bone directly skips points altogether; that is the right choice for placements a pack author has hand-tuned for one specific model.

Mirrored Points

A mirror point renders the attachment as a mirrored re-bake of the same geometry, with winding and normals corrected. Poses and physics mirror automatically, so a symmetric pair folds and swings symmetrically. Author one side; the mirror is free.

Shipped Universal Points

Townstead pre-ships a universal humanoid set under the townstead namespace, so packs targeting standard anatomy need no point files of their own:

Point	Bone	Tag	Mirror
townstead:left_ear	head	ear	no
townstead:right_ear	head	ear	yes
townstead:horn	head	horn	no
townstead:brow	head	brow	no
townstead:snout	head	snout	no
townstead:crown	head	crown	no
townstead:tail_root	body	tail_root	no
townstead:back	body	back	no
townstead:wing_root_left	body	wing_root	no
townstead:wing_root_right	body	wing_root	yes

Head points ride the head bone, so ears, horns, and snouts follow head turns; body points follow the torso. A pack can add its own points, and a rig-specific pack can re-place any of these tags for its body via rig scoping.