Modelling a level

The geometry of a level: what to model, how to light it, how to mark water, lava and pits, and how to export. Studio checks every file with the game’s own track importer, so these rules are the game’s.

Set up the scene

Y is up, as in Blender’s glTF export (keep +Y Up on).
One Blender unit is one game unit. For a sense of size: a step between platforms of 25 units is easy to climb, a door is about 144 high, the sample field is 2000 × 2000. Every position must stay within -32768…32767.
Collision is the drawn triangles. Model the floor the player walks on as real faces. There’s no separate collision mesh unless you make one (a collider surface).
Faces are counter-clockwise seen from their front (Blender’s normal direction). Turn on Backface Culling in the viewport to see which way faces point.

Ramps and steps: the hero can’t climb a lip. Start ramps a little below the ground they rise from, and keep raised floors (a bridge deck) reachable by a ramp rather than a step up. Juno walks under a deck she can’t step onto and falls.

Light it with vertex colours

The game’s levels are lit by vertex colours: the baked light is the main look. Paint or bake into a colour attribute (byte colour, face corner or point). It’s exported as COLOR_0 and multiplied with the texture: white is “as the texture”, darker is shadow. No vertex colours means full bright. The add-on’s Bake vertex light does this for you.

Textures and materials

One image per material, as PNG. Small is right for an N64 game: 16×16 to 64×64. Studio cuts larger ones to sizes that fit the console’s texture memory.
UVs may repeat past 0…1 (tiling).
New images are scarce: each becomes a new 3D texture, and the game’s table has room for about three. Reuse images across materials (lava can reuse a stone image under red vertex colours). Studio’s import check counts them.
Special surfaces come from words in the material name (anywhere, separated by _, -, a space or a dot):

Word	In the game
`water`	A water surface (see-through): the hero swims below its height. A flat face at the water’s height, with alpha in the texture
`lava` or `damage`	A damage floor: pushes the hero and hurts
`kill`	A kill plane: a pit floor that kills, below a drop
`collider`	Invisible but solid: walls that block without being drawn
`nocollide`	Drawn but not solid: grass tufts, decoration

Examples: rock_lava, pit_kill, glass_collider, pond_water.

Advanced: the custom properties batchFlags, pass (opaque / translucent) and triangleFlags on a material set the flags directly. Turn on Custom Properties in the export to keep them.

Export

File › Export › glTF 2.0 (or the add-on’s Export for JFG-Studio):

Format: glTF Binary (.glb).
Include: Selected or Visible Objects (only the level), Custom Properties on.
Transform: +Y Up on.
Mesh: Apply Modifiers on, UVs on; vertex colours: the active one.
Materials: Export; images Automatic (PNG).
No animation, no armature: a level is static geometry.

Checklist before Play

The level has a floor under the start point (Studio places objects on the floor it finds).
Pits have a kill floor, or the hero falls forever.
As few new images as you can.
Studio’s import check has no errors, and Validate shows none either.

When the check complains

Message	Fix in Blender
A vertex out of range	Move the level closer to the origin, or make it smaller
A non-triangle primitive	Remove loose edges and points (export meshes only)
Two materials give one texture different images	Give each image its own material
Doesn’t fit the track buffer	Fewer triangles, or split the level in two
More than 127 segments	Studio splits big meshes for you; a level this large needs splitting into two levels