Fit an accessory to a rigged 3D model for Directional Sprites: an item GLB (a sword, a gun, a staff, a bow, a shield, a helmet, a hat, a backpack...) held by one bone of the model - a hand, the head, the back or the hips. Nothing is saved. The item is first placed automatically for its `kind` (a sword by its handle, a gun by its pistol grip, a shield on the forearm, a helmet over the head, a backpack on the back), and the hand closes round it. Adjust it relative to that automatic fit with `size` (% of it), `move` (% of the character's height along forward/up/out) and `turn` (degrees about those axes), and call again with the new values until it looks right: each call starts from the automatic fit, so send the full adjustment every time. The response has the `placement` to pass to attachDirectionalAccessories, `checks` (how far the item sinks into the body, how far its grip is from the palm, how much of the head pokes through a helmet, each in % of the character's height or of its vertices), and, unless `preview` is false, `model_url` (the model holding the item, a GLB kept 7 days) and `previews`: frames of the model walking with it, seen from SW and SE, like previewDirectionalSprites' (which this shares: one preview at a time, a newer one cancels the older, which then comes back without previews). Free (no credits) and synchronous; a fit takes a few seconds with previews. Requires an API key (user scope).

The rigged 3D model, as a URL or base64-encoded GLB file - create3DModel with rig true, or rigModel. Up to 30MB; a larger file is rejected with HTTP 400.

The item, as a URL or base64-encoded GLB file - any 3D model (create3DModel without rig, standing as generated). Up to 30MB.

What the item is, in words ("rusty sword"). Used to guess kind when it is omitted, and as the item's name when saved.

What the item is, which decides how it is first held: blade (sword, axe, dagger, mace, wand...: by its handle, pointing forward), gun (by its pistol grip, barrel forward), staff (spear, polearm: at its middle, upright), bow (at its middle, upright), shield (on the forearm, facing out), helmet (over the head, sized to it), hat (hat or crown: on top of the head), back (backpack, quiver: flat on the back), other. Omit to guess it from name and the item's shape (other when unsure).

Where the item goes. Omit for where its kind goes (a bow and a shield in the left hand, a helmet or hat on the head, a backpack on the back, anything else in the right hand). The response lists the points this skeleton has.

A bone of the model's skeleton to hold the item, by name, instead of point.

The item's size in % of the automatic fit's (100 = as fitted, 150 = half as big again).

Hold the item by its other end (when the automatic fit grabbed it by the wrong end).

Close the hand round the item (on a skeleton with finger bones).

Render previews and host the model holding the item. False answers only the fit and its checks, in about a second.

The animation preset (listAnimationPresets) the previews show the model doing with the item.

What the item was fitted as (as sent, or guessed).

The attach point the bone is, if it is one.

The bone holding the item.

The model holding the item, as a GLB (kept 7 days). Unless preview is false.

Why there are no previews, when they could not be made (the fit itself is still valid).