Direction affected by itself

[pirosow]

Hello, sorry if that’s a dumb question, but:

I’m trying to make a pathtracing script. It scans from left to right, then rotates up by a bit.

I have this script that creates a direction for a ray.
However, when changing the x direction, it goes to a completely different direction, so it’s affected by itself?

I’m trying to create a direction that’s based on a 0, 0, 0 vector, so I can make it point where I want without it being affected by itself.

local fov = 60

— resolution
local resX = 10
local resY = 10

local xIndex = 0
local yIndex = 0

— function that creates the ray origin and direction
function getRay()
    yIndex = yIndex + 1

    — rotates up when xIndex gets past x resolution
    if yIndex > resY then
        yIndex = 0
        xIndex = xIndex + 1
    end
    
    local baseDirection = Vector3.new(0, 0, 0)
    
    — how much x and y rotates based on their index

    local yIncrement = -fov / 2 + fov / resX * xIndex
    local zIncrement = -fov / 2 + fov / resY * yIndex

    local direction = baseDirection + Vector3.new(yIncrement, zIncrement, 0)

    print(direction)
    
    return Ray.new(eye.Position, direction)
end

The yellow parts in the first image get created each time I call the function, and have the same direction as the one in the function.

I expected the parts to rotate like the second image (that’s when I leave the direction’s x to 0):
scans from left to right.

Console, when I call the function multiple times:

-30, -24, 0
-30, -18, 0
-30, -12, 0
-30, -6, 0
-30, 0, 0
-30, 6, 0
…
-30, 30, 0
-24, -30, 0
-24, -24, 0
-24, -18, 0
-24, -12, 0
-24, -6, 0
-24, 0, 0
-24, 6, 0
-24, 12, 0

Sorry if it’s not very clear… Thanks!

[azqjanna]

Are you trying to make a disc like the second image?

[pirosow]

Yes, but with the horizontal axis changing with the script

For example, it would start pointing at the bottom left. Every time I call the function, it would rotate slightly to the right until it points to bottom right. Then, when it’s at the limit of the fov, it would point back to the left, and rotate slightly upwards. It would continue doing that until it points to the top right.

So I’m trying to make it scan the field of view, to make a path tracing engine

[pirosow]

Turns out I didn’t know how rays worked properly, sorry. I managed to figure it out!