Align to spatial mesh?

I want to align gameobjects that use “TapToPlace” to the mesh created by spatial mapping.

I think I’m on the right track by modifying the TapToPlace.cs script. I have added a public gameobject which I drag the cursor object to, and then I have modified the following code:

if (Physics.Raycast(headPosition, gazeDirection, out hitInfo, 30.0f, spatialMappingManager.LayerMask))
                {
                    // Rotate this object to face the user.
                    Quaternion toQuat = Camera.main.transform.localRotation;
                    toQuat.x = 0;
                    toQuat.z = 0;

                    var cursorRotation = cursor.transform.localRotation; // get cursors rotation

                    // Move this object to where the raycast
                    // hit the Spatial Mapping mesh.
                    // Here is where you might consider adding intelligence
                    // to how the object is placed.  For example, consider
                    // placing based on the bottom of the object's
                    // collider so it sits properly on surfaces.
                    if (PlaceParentOnTap)
                    {
                        // Place the parent object as well but keep the focus on the current game object
                        Vector3 currentMovement = hitInfo.point - gameObject.transform.position;
                        ParentGameObjectToPlace.transform.position += currentMovement;
                        ParentGameObjectToPlace.transform.rotation = toQuat;
                    }
                    else
                    {
                        gameObject.transform.position = hitInfo.point;
                        //gameObject.transform.rotation = toQuat; // old code
                        gameObject.transform.rotation = cursorRotation; // new rotation
                    }
                }

However, it just doesn’t seem quite right. Especially, when trying to place an object on a ceiling, it does not face downwards.

[angelaHillier]

You might need to call RecalculateNormals() for the SpatialMapping mesh in order to tell the difference between a floor/ceiling/wall, etc.

In the Holograms 230 Academy version of the HoloToolkit, SpatialMappingObserver.cs will call this after creating a new mesh when you set the ‘RecalculateNormals’ option to ‘true’. This is done in the SurfaceObserver_OnDataReady() function:

if (RecalculateNormals)
{
    MeshFilter filter = surface.GetComponent<MeshFilter>();
    if(filter != null && filter.sharedMesh != null)
    {
          filter.sharedMesh.RecalculateNormals();
    }
}

I don’t believe this option was ever added to the official HoloToolkit, but it might be a good addition for cases when the meshes need to have the correct normals.

[StephenHodgson]

Going to close this. It’s probably been archived by google by now.