Importing electrode positions recorded in RAS coordinates

[tbone]

Hello

I am trying to load electrode coordinates with a subject's T1w image.
The electrodes were recorded in RAS coordinates (origin point: defined by the MRI scanner).

From the forum I've seen that the T1w is placed in world (scanner) coordinates, so I thought using the exact values would place the positioning on the expected 10-10 location.

However, the positions were way off which led to using the image transform as such:

nii = nib.load("Image.nii.gz")
affine = nii.affine
inv_affine = np.linalg.inv(affine)

ras_x = a
ras_y = b
ras_z = c

ras_h = np.array([ras_x , ras_y, ras_z, 1])
voxel = inv_affine @ ras_h
voxel_vec = model.Vec3(voxel[0], voxel[1], voxel[2])
world_pos = t1w.Transform * voxel_vec
electrode = model.CreateSolidSphere(world_pos, 10.0)

But even with this, I could not correctly register my electrode positions.

I would greatly appreciate any help on this! Thank you for your time in advance