Horn Auto Fit — Attach horns to the top of your avatar's head in one click [VRChat / Unity]

Horn Auto Fit is a Unity editor extension that attaches horns to your avatar's head in one click. It finds the hair surface and the head skin on top of the head and puts the horns' base slightly into the hair (for a pair, under each base). It sizes the horns to the avatar (based on where their creator placed them when their origin is at the avatar's feet; otherwise the size is kept and a note is shown), and makes them follow the head (Modular Avatar BoneProxy if present, otherwise they become a child of the Head bone). It can also hide the avatar's own horns (renderers whose names contain horn, ツノ or 角) with one checkbox. Original meshes and textures are not modified. Undo with Ctrl+Z.

No horn or avatar models are included (tool only).

Free vs Full

• Free trial: try the one-click fit on your own avatar and see the result. Preview only: it goes back after 30 seconds, or when you save the scene, enter Play mode, press Ctrl+Z or close the window.
• Full: keeps the result, plus sliders for front/back position, depth into hair, tilt, and size.

Try the Free trial with your own horns and avatar first to see how it fits. Importing the Full version over the Free version replaces it.

Carefully tested before release

Made by Kotokoto Lab, an independent creator. This version was tested on 3 popular free avatars plus the chibi version of one of them, with free horns from BOOTH and our own samples. The results — including where it does not work well — are written below.

Tested with 10 horns on 4 avatars (40 combinations): 6 from 3 free BOOTH items (antlers, a unicorn horn, ram horns that spread beside the ears, one-piece ram horns, only the left one of a left/right separate pair, horns with rose decorations) and 4 self-made samples. With the 4 self-made samples (16 combinations), the base went about 0.2 to 2.3 cm below the hair surface. This tool is for horns that go on top of the head: in the BOOTH tests, horns that spread out beside the ears floated a few cm away from the head on 2 avatars and sat at chin height on 1, and horns with rose decorations dropped to the side of the face on 1 avatar; antlers, the unicorn horn and the one-piece ram horns went on top of the head. Horns meant for the sides of the head cannot be fitted by this tool; move them by hand. Left/right separate horns keep their creator's spacing (checked with the left one only). Hiding the avatar's own horns was checked on all 4 avatars with a sample named "Horn". On the 3 adult-sized avatars with 4 horns (a plain sample, a sample with BoneProxy, and 2 BOOTH horns), position and size stayed the same after the upload-time processing (Modular Avatar / Avatar Optimizer). Hoods and hats are not used as the attach surface (the horns go on the hair under them): long horns poke through, short ones are hidden, so hide hoods and hats first. On chibi avatars with large heads, the horns come out about 1/3 the adult size and may be barely visible; the Full version can enlarge them up to 2x.

Requirements

Unity 2022.3 (tested on 2022.3.22f1), Humanoid avatar with Head and neck bones. Works without Modular Avatar.

How to install

• Download the .unitypackage (Free or Full) and drag it into the Project window, then click Import.
• Open Tools > Horn Auto Fit. The window has an "English" checkbox at the top.

Terms

OK for personal and commercial use. Do not redistribute or resell the tool. Follow each creator's terms for avatars and horns. Use at your own risk; back up important projects first.

Questions or bug reports: please send a message through the shop.