converts from one format to another deterined by the extensions of the input and output:

flint convert models/mymod_mob.b3d models/mymod_mob.glb
flint convert models/mymod_table.obj models/mymod_table.lua
flint convert models/mymod_table.obj models/mymod_table.lua --scale 0.5
flint convert locale/mymod.de.tr locale/mymod.de.po

an existing output file is overwritten. .lua files are formatted like flint format does, with its settings from flint.toml.

b3d to glTF

ported from modlib’s converter. meshes, normals, vertex colors, texture coordinates, bones and their weights, and keyframes are converted, so the model loads in Luanti like the .b3d did. .glb is recommended, as it’s smaller.

usually only the file name in the mod needs changing:

• frame numbers stay the same, so set_animation ranges keep working
• textures keep applying to the same parts of the model
• the model faces the same way

the exception is a static model used as a node’s mesh: Luanti uses 1 unit per node for static .b3d models, but 10 for glTF, so multiply the node’s visual_scale by 10. animated models and entities use 10 units per node for both.

what Luanti ignores in a .b3d is left out, e.g. texture flags and brush blend modes. a warning is printed for anything that changes how the model looks, e.g. scaled textures, which Luanti stretches the texture coordinates of for .b3d but not glTF.

obj to node box

ported from objtonodebox. every connected part of the model, i.e. vertices joined by faces, becomes a box around it, so a model made of cuboids becomes a node box of those cuboids. the X axis is flipped, like Luanti does for .obj models, so the node box lines up with the mesh.

the result is a Lua file returning the node box, to use as is or copy into the node definition:

return {
	type = "fixed",
	fixed = {
		{ -0.5, 0.375, -0.5, 0.5, 0.5, 0.5 },
		{ 0.3125, -0.5, -0.4375, 0.4375, 0.375, -0.3125 },
	},
}

local node_box = dofile(core.get_modpath("mymod") .. "/models/mymod_table.lua")

core.register_node("mymod:table", {
	drawtype = "mesh",
	mesh = "mymod_table.obj",
	selection_box = node_box,
	collision_box = node_box,
	-- ...
})