CFL Tool

A 3DS homebrew app for previewing Mii heads (and full-body Miis) rendered by cfl-mii.

cfl-mii is a reimplementation of Nintendo's own CFL Mii-rendering library, reverse-engineered from a retail 3DS title binary's debug info and cross-referenced against the real, compiled RFL (Wii) and FFL (Wii U) Mii libraries - it is not Nintendo's own code, and it is not guaranteed to be 100% functionally accurate to real CFL. Most of it has been validated against real 3DS hardware output, but some corners (exact pixel-level texture formulas, a handful of edge cases in rarer Mii data combinations) are still being tracked down. Where this project found and fixed a real discrepancy from official Mii Maker/Mii Plaza output, it's noted in cfl-mii's own commit history and code comments - if something here looks visibly wrong compared to a real Mii Maker render, it's more likely an unfinished corner of this reimplementation than an intentional difference.

Building

cfl-mii is a git submodule that builds as a static library (libCFL.a), which this app links as -lCFL:

git clone --recursive https://github.com/jamesrhg/cfl-tool.git
cd cfl-tool
make        # builds external/cfl-mii's libCFL.a first, then cfl-tool.3dsx

Needs devkitARM/devkitPro (with citro2d/citro3d). If you cloned without --recursive, run git submodule update --init first.

cfl-mii itself only ever builds and renders a Mii head. Real CFL has no body-model concept anywhere (confirmed via the decompile), so this app owns everything below the neck entirely on its own side - real, standard IQM parsing, per-vertex linear-blend skinning, per-Mii build/height scaling, and skeletal animation sampling are all plain application code in source/main.c, built against nothing but cfl-mii's own public API (CFLCharModel/CFLPart, CFL_GetShaderLocations, CFL_BindDefaultShader/CFL_SetDefaultMaterial). See Body models below for the full picture.

Features

• CharModel Test - pick one or more Miis from the system Mii Selector and view them rendered as full 3D character models, with a free-orbiting camera and per-head auto-spin. Several resolution / expression-set presets are available depending on how many heads you want on screen at once.
• CharModel + Body Test - a single Mii's head attached to a full-body model, rendered in real time with the same free camera as CharModel Test. Two real body sources, swapped with Y: the real Nintendo Mii Maker bodies (MaleBody/FemaleBody, scaled per that Mii's own real build/height) and the real StreetPass Mii Plaza bodies (StreetPassBodyMale/StreetPassBodyFemale, fixed size - matching how the real StreetPass Mii Plaza game itself displayed them).
• Icon Test - renders a Mii through cfl-mii's own real CFL_CommandMakeModelIcon (head only) and displays the resulting icon texture at two sizes, transparent background. X toggles to a second, body-enabled pair rendered by this app's own appMakeModelIconWithBody - a from-scratch reimplementation of CFL_CommandMakeModelIcon's own real camera/render-target/depth setup that also draws a real IconBody alongside the head, entirely on this app's own side (cfl-mii itself has no body-attached icon path at all). Both pairs are pre-rendered up front when you pick a Mii - X just swaps which one is shown, no re-rendering on every press. The on-screen label always names whichever real function actually produced the icon currently displayed.
• CharModel from Data - decodes a sample CFLStoreData (the standard checksummed Mii exchange format) straight into a rendered CharModel, and lets you pick any Mii from the system selector and re-encode it back to base64 CFLStoreData - a round-trip demo of CFL_MakeStoreData/CFL_IsStoreDataValid.

Controls

• D-Pad - navigate menus / pan the camera
• A - confirm
• B - back
• X - screen-dependent: cycle facial expression (CharModel Test), toggle the attached body icon pair (Icon Test), pause/resume the body animation when one is active (CharModel + Body Test)
• Y - CharModel + Body Test only: swap between the Mii Maker and StreetPass body sources
• SELECT - replace the last Mii in the current scene
• Circle Pad - look around
• L / R - zoom camera in/out
• START - exit

Building

Requires devkitPro with the 3DS toolchain (devkitARM, libctru, citro3d, citro2d) installed.

git clone --recurse-submodules <this-repo-url>
cd cfl-tool
make

If you already cloned without --recurse-submodules:

git submodule update --init --recursive

Produces cfl-tool.3dsx.

Body models

All six of data/*.iqm (MaleBody, FemaleBody, IconBody, StreetPassBodyMale, StreetPassBodyFemale, DefaultAnim) are real, standard IQM (Inter-Quake Model) files - the same open format Blender's own importer/exporter and several other engines support, not a project-specific format - extracted once, offline, from real Nintendo body assets, and embedded into the .3dsx the same way the vertex shader is, via devkitPro's own bin2o mechanism (see the DATA directory in the Makefile) - no extra runtime asset loading or network access involved.

Every piece of body handling lives entirely in this app, not in cfl-mii: the real IQM parser (joints, meshes, linear-blend skinning vertex arrays), per-Mii build/height scaling (nn::mii::detail::GetBodyScale, applied only to the Mii Maker bodies - the StreetPass bodies render at a fixed size, matching how the real StreetPass Mii Plaza game itself used them), and a from-scratch anim-only .iqm reader/sampler for DefaultAnim.iqm are all plain C in source/main.c. This is a deliberate architecture choice, not a missing feature in cfl-mii - see the note at the top of this README and cfl-mii's own README for why.

Body animation playback exists but is currently disabled. DefaultAnim.iqm was authored against the female Mii Maker body's own bind pose - replaying it unmodified on the male body's differently- proportioned skeleton visibly misaligns the neck (no per-body retargeting is implemented yet). Body Test always shows the plain bind pose (T-pose) for both bodies until a real, per-body-retargeted clip (or a body-proportion-independent one) exists - the sampling/posing code itself (sampleBodyAnimFrame/poseBodyModel) is intact and already used once this is revisited.

The StreetPass bodies' own real pants/skin split is a texture-based mask in the original asset (a real, plain black/white palette texture, never shipped alongside the model), not a second mesh the way Mii Maker's MaleBody/FemaleBody use - parseBodyIqm's own splitBottomCircleFromBody reconstructs the real boundary geometrically (position + radius) instead, calibrated against a real independent rip of the same asset that does include the original texture and UV data.