In general, a person who uses materials of their own to make a different category of thing becomes the owner of that thing. For example, a carpenter who makes a cupboard by cutting, shaping and joining pieces of their own wood will own the cupboard.
If somebody else owned the materials used to make the new thing, then questions of ownership depend on whether the raw materials have lost their identity.
If the raw materials have not lost their identity, and the new thing can be returned to its former state, then the owner of the raw materials may still own them. For example, suppose A uses planks of wood belonging to B to make a bookcase, simply by placing bricks between the planks at each end. Even though they have been made into a bookcase, B's planks have not lost their identity, and can easily be restored to their former state.
If the raw materials have lost their identity, and the new thing cannot be returned to its former state, then the maker of the new thing becomes its owner. For example, a carpenter who makes a cupboard by cutting, shaping and joining pieces of wood belonging to another person will own the cupboard, provided they did not knowingly use another another's materials in bad faith. But the person who owned the raw materials may be entitled to compensation for conversion.
If the maker of the new thing acted in bad faith, such as a thief of the materials used, then the owner of the raw materials becomes owner of the new thing, even if the raw materials have lost their identity.