I’m certainly no expert but have dabbled with modding MC before. From what I remember…
The mouse position alone will not work, make a radius around player that returns the position and side/face of the block your mouse is over.
Your mouse event should capture these values and pass them to your new block method. The new block method can then use the Vector3 as a position starting point and then use the side/face value to control the direction of the offset.
Hope this helps in some way
thanks.I did not know that I needed a 3d position.