How do I find my mouse point in a scene using SceneKit?

Question

I have set up a scene in SceneKit and have issued a hit-test to select an item. However, I want to be able to move that item along a plane in my scene. I continue to receive

Answer 1

I used the code written by Steve and with little modification it worked for me.

On mouseDown I save clickWorldCoordinates on a property called startClickWorldCoordinates.

On mouseDragged I calculate the selectedPiece position in this way:

SCNVector3 worldClickCoordinate = [(SCNView *) self.view unprojectPoint:clickCoordinates.x];

newPiecePosition.x = selectedPiece.position.x + worldClickCoordinate.x - startClickWorldCoordinates.x;
newPiecePosition.y = selectedPiece.position.y + worldClickCoordinate.y - startClickWorldCoordinates.y;
newPiecePosition.z = selectedPiece.position.z + worldClickCoordinate.z - startClickWorldCoordinates.z;

selectedPiece.position = newPiecePosition;

startClickWorldCoordinates = worldClickCoordinate;