I have a function which converts some 3D coords (x, y, z) into a position in the screen (width, height), with an isometric perspective (true isometric, not dimetric).
Coords_3D_To_2D (x, y, z) {
return {
w: ((x-y) * (Math.sqrt(3)/2)),
h: (((-x-y) / 2) -z)
}
}
So, for better clarification, here we have the blue lines, which represents the 2D Screen, and the black lines, which represents the 3D isometric space:
The above function works fine. If I invoke it like this, for example: Coords_3D_To_2D(15, -10, 5)
it returns { w: 21.65, h: -7.5 }
, which will be the point projected in the 2D screen (in this case, it would be outside screen, but that doesn't matter).
So the projection 2D -> 3D seems to be working. But what I would like is to have a function which inverts that; it should receive some coords of the 2D Screen (w, h), and also some given value for the z-index, and return the corresponding 3D isometric point.
It should be something like this (here, I assigned a value of 5 for the z-index):
Coords_2D_To_3D (w, h, z = 5) {
return {
x: ?,
y: ?,
z: 5
}
}
CodePudding user response:
2 equations with 2 variables. Solvable.
function Coords_3D_To_2D(x, y, z) {
return {
w: ((x - y) * (Math.sqrt(3) / 2)),
h: (((-x - y) / 2) - z)
}
}
console.log(Coords_3D_To_2D(15, -10, 5))
function Coords_2D_and_Z_To_3D(w, h, z) {
var y = -(h z w / Math.sqrt(3))
var x = 2 * w / Math.sqrt(3) y
return {x, y, z}
}
console.log(Coords_2D_and_Z_To_3D(21.650635094610966, -7.5, 5))