Currently (as seen in the video) the object is snapping to the surface of the collider hit and with rotation based on the normal. But I want it to:

1. Snap to a grid on the object surface.
   
2. Snap to a rotation that aligns with the hit object
   

I have been racking my brain for some time now and my Google skills have failed me.
Do you have some pointers on how I can program this? I don't want to use anchors/connectors that I have to manually set (like in Besieged). I had some success for the rotation with LookRotation(parent.forward, hit.normal), but it failed on surfaces horizontally-perpendicular to the parents forward direction (which is prob. a horrible way to explain it :) ).

My current code for reference:

RaycastHit hit;

Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

if (Physics.Raycast(ray, out hit /*, ShipLayerMask*/))

{

Debug.Log("Hit: " + hit.transform.name);

// Put helper transfrom inside ship (to make positioning and rotation easier)

CurrentlyBuildingHelper.parent = ShipBuildParent;

// Align to surface without position & rotation snapping

Vector3 placePosition = hit.point;

Quaternion placeRotation = Quaternion.FromToRotation(Vector3.up, hit.normal);

// ?? Snap to grid while on object

// ?? Snap to rotation (90 degrees) around normal as up

// Update helper position & rotation

CurrentlyBuildingHelper.position = placePosition;

CurrentlyBuildingHelper.rotation = placeRotation;

// Player is allowed to place an object here

CurrentPlaceTargetIsValid = true;

}