L21 — Fast64 materials & glTF export

Goal

Export a model Tiny3D accepts: either Fast64 (best) or the course f3d inject helper (good enough for class props).

Path A — Fast64 (recommended for real games)

1. Install Fast64 into Blender.
2. Create F3D materials (not only Principled).
3. Use a vertex-colored texture preset when blending texture × Col.
4. Export glTF Binary:
   • Include → Custom Properties enabled
   • Selected objects if needed
5. Convert:

source scripts/env.sh
gltf_to_t3d myprop.glb filesystem/myprop.t3dm
mkasset -c 2 -o filesystem filesystem/myprop.t3dm

Place textures (PNG) beside the export; importers/tools emit sprites.

Export footguns

Symptom	Fix
Material has no fast64 data	Custom Properties off, or not F3D material
Missing textures	PNG path wrong; re-export; check sprite names
Inside-out mesh	Recalculate normals outside; winding
Huge/tiny	Apply scale; match course units

Path B — Course inject (no Fast64)

For placeholders and class machines without the addon:

python3 scripts/gltf_inject_f3d.py raw.glb fixed.glb
gltf_to_t3d fixed.glb out.t3dm

common/lesson.mk runs this inject automatically when converting assets/*.glb.

Inject is a teaching bridge

It attaches a generic shade/lighting material. It will not replace learning Fast64 combiners for production look.

Lesson Makefile integration

Drop files in a lesson’s assets/:

• *.glb → inject → .t3dm
• *.png → .sprite
• prebuilt *.t3dm / *.sdata copied through

Lesson code

Module 3 is Blender-first — there is no per-lesson C ROM for L17–L25.

Runnable code that loads the course meshes lives in the Module 3 asset lab checkpoint (lessons/m3-asset-lab/).

Next

L22 — Player & platform.