Move triangle utils from "minetest" to "vector"

This commit is contained in:
Lars Mueller 2020-12-21 19:59:26 +01:00
parent 7fde587dab
commit 3631b1c4ca
2 changed files with 38 additions and 38 deletions

@ -263,42 +263,6 @@ function get_liquid_flow_direction(pos)
return dir return dir
end end
--+ Möller-Trumbore
function ray_triangle_intersection(origin, direction, triangle)
local point_1, point_2, point_3 = unpack(triangle)
local edge_1, edge_2 = vector.subtract(point_2, point_1), vector.subtract(point_3, point_1)
local h = vector.cross(direction, edge_2)
local a = vector.dot(edge_1, h)
if math.abs(a) < 1e-9 then
return
end
local f = 1 / a
local diff = vector.subtract(origin, point_1)
local u = f * vector.dot(diff, h)
if u < 0 or u > 1 then
return
end
local q = vector.cross(diff, edge_1)
local v = f * vector.dot(direction, q)
if v < 0 or u + v > 1 then
return
end
local pos_on_line = f * vector.dot(edge_2, q);
if pos_on_line >= 0 then
return pos_on_line
end
end
function triangle_normal(triangle)
local point_1, point_2, point_3 = unpack(triangle)
local edge_1, edge_2 = vector.subtract(point_2, point_1), vector.subtract(point_3, point_1)
return vector.normalize{
x = edge_1.y * edge_2.z - edge_1.z * edge_2.y,
y = edge_1.z * edge_2.x - edge_1.x * edge_2.z,
z = edge_1.x * edge_2.y - edge_1.y * edge_2.x
}
end
--+ Raycast wrapper with proper flowingliquid intersections --+ Raycast wrapper with proper flowingliquid intersections
function raycast(pos1, pos2, objects, liquids) function raycast(pos1, pos2, objects, liquids)
local raycast = minetest.raycast(pos1, pos2, objects, liquids) local raycast = minetest.raycast(pos1, pos2, objects, liquids)
@ -415,10 +379,10 @@ function raycast(pos1, pos2, objects, liquids)
{corner_levels[1], corner_levels[2], corner_levels[3]}, {corner_levels[1], corner_levels[2], corner_levels[3]},
{corner_levels[1], corner_levels[3], corner_levels[4]} {corner_levels[1], corner_levels[3], corner_levels[4]}
} do } do
local pos_on_ray = ray_triangle_intersection(relative, direction, triangle) local pos_on_ray = modlib.vector.ray_triangle_intersection(relative, direction, triangle)
if pos_on_ray and pos_on_ray <= length then if pos_on_ray and pos_on_ray <= length then
pointed_thing.intersection_point = vector.add(pos1, vector.multiply(direction, pos_on_ray)) pointed_thing.intersection_point = vector.add(pos1, vector.multiply(direction, pos_on_ray))
pointed_thing.intersection_normal = vector.multiply(triangle_normal(triangle), -1) pointed_thing.intersection_normal = vector.multiply(modlib.vector.triangle_normal(triangle), -1)
return pointed_thing return pointed_thing
end end
end end

@ -86,3 +86,39 @@ function box_box_collision(diff, box, other_box)
end end
return true return true
end end
--+ Möller-Trumbore
function ray_triangle_intersection(origin, direction, triangle)
local point_1, point_2, point_3 = unpack(triangle)
local edge_1, edge_2 = vector.subtract(point_2, point_1), vector.subtract(point_3, point_1)
local h = vector.cross(direction, edge_2)
local a = vector.dot(edge_1, h)
if math.abs(a) < 1e-9 then
return
end
local f = 1 / a
local diff = vector.subtract(origin, point_1)
local u = f * vector.dot(diff, h)
if u < 0 or u > 1 then
return
end
local q = vector.cross(diff, edge_1)
local v = f * vector.dot(direction, q)
if v < 0 or u + v > 1 then
return
end
local pos_on_line = f * vector.dot(edge_2, q);
if pos_on_line >= 0 then
return pos_on_line
end
end
function triangle_normal(triangle)
local point_1, point_2, point_3 = unpack(triangle)
local edge_1, edge_2 = vector.subtract(point_2, point_1), vector.subtract(point_3, point_1)
return vector.normalize{
x = edge_1.y * edge_2.z - edge_1.z * edge_2.y,
y = edge_1.z * edge_2.x - edge_1.x * edge_2.z,
z = edge_1.x * edge_2.y - edge_1.y * edge_2.x
}
end