EinsDreiDreiSieben/mods/character_anim/workaround.lua
2025-05-13 23:14:13 +02:00

54 lines
1.4 KiB
Lua

-- See https://github.com/luanti-org/luanti/issues/15692
local mod = modlib.mod
local b3d = modlib.b3d
local media_paths = modlib.minetest.media.paths
local function is_perfect(quat)
local mat = modlib.matrix4.rotation(quat)
local diag_abs_sum = 0
for i = 1, 3 do
diag_abs_sum = diag_abs_sum + math.abs(mat[i][i])
end
return math.abs(diag_abs_sum - 3) < 1e-5
end
return function(name)
local stream = assert(io.open(media_paths[name], "rb"))
local character = assert(b3d.read(stream))
stream:close()
local function wiggle_rotation(quat)
if math.abs(quat[1]) + math.abs(quat[2]) + math.abs(quat[3]) < 1e-5 then return quat end -- identity
if not is_perfect(quat) then return quat end
local wiggled = {}
for i = 1, 4 do
wiggled[i] = quat[i] + 1e-3
end
wiggled = modlib.quaternion.normalize(wiggled)
if not is_perfect(wiggled) then return wiggled end
for i = 1, 4 do
wiggled[i] = quat[i] - 1e-3
end
wiggled = modlib.quaternion.normalize(wiggled)
if not is_perfect(wiggled) then return wiggled end
return quat -- this shouldn't happen
end
local function wiggle_rotations(node)
node.rotation = wiggle_rotation(node.rotation)
node.keys = {}
for _, child in ipairs(node.children) do
wiggle_rotations(child)
end
end
wiggle_rotations(character.node)
local rope = {}
character:write({write = function(_, str)
table.insert(rope, str)
end})
return table.concat(rope)
end