Tap to place (but not on a mesh)

bulgogi

Hi,

I want to be able to move a hologram similar to the Holograms App on the Hololens. For example, when you select a hologram, you can place it anywhere in your room, it does not have to touch a mesh. This way, I can have a hologram float in the air.

I've been able to use the TapToPlace script to select my hologram and use gaze to move the hologram to where it hits a mesh. This makes sense to me. However, to have a hologram float in the air means my gaze will not be intersecting a point for placement.

Any suggestions on how to get started?

DavidKlineMS

@bulgogi,
Essentially, you want to be doing the same thing thing that TapToPlace does, except that you stop moving the hologram with your gaze without checking for a surface mesh intersection.

If you set the GazeManager's MaxDistance property a distance closer than the 15m default, you can simply use it's Position property to place your hologram.

If want to also see surfaces further than a given distance (ex: 3m) you can grab the following line of code and use it in your script.

Vector3 position = Camera.main.transform.position + (Camera.main.transform.forward * distance);

Thanks!
David

DavidKlineMS

@bulgogi,
Take a look at Placeable.cs in the Holograms 230 course. It handles keeping an object parallel to the wall.

The method to look at is called OrientObject.

private void OrientObject(bool alignToVerticalSurface, Vector3 surfaceNormal)
{
    Quaternion rotation = Camera.main.transform.localRotation;

    // If the user's gaze does not intersect with the Spatial Mapping mesh,
    // orient the object towards the user.
    if (alignToVerticalSurface && (PlacementSurface == PlacementSurfaces.Vertical))
    {
        // We are placing on a vertical surface.
        // If the normal of the Spatial Mapping mesh indicates that the
        // surface is vertical, orient parallel to the surface.
        if (Mathf.Abs(surfaceNormal.y) <= (1 - upNormalThreshold))
        {
            rotation = Quaternion.LookRotation(-surfaceNormal, Vector3.up);
        }
    }
    else
    {
        rotation.x = 0f;
        rotation.z = 0f;
    }

    gameObject.transform.rotation = rotation;
}

Thanks!
David

Patrick

Hey Bulgogi,
One thing to try is rather than boundsAsset.tranform.parent, try boundsAsset.transform.SetParent(gameobject.transform, false);

the false will tell unity not to attempt to preserve the scale and position of the object while reparenting. Otherwise, if your parent as a really small scale the boundsAsset local scale will become really huge to compensate.

DavidKlineMS

@bulgogi,
Essentially, you want to be doing the same thing thing that TapToPlace does, except that you stop moving the hologram with your gaze without checking for a surface mesh intersection.

If you set the GazeManager's MaxDistance property a distance closer than the 15m default, you can simply use it's Position property to place your hologram.

If want to also see surfaces further than a given distance (ex: 3m) you can grab the following line of code and use it in your script.

Vector3 position = Camera.main.transform.position + (Camera.main.transform.forward * distance);

Thanks!
David

bulgogi

David,

Thank you for the quick reply. That makes a lot of sense actually. I'll give it a try and report my findings later. Many thanks!

DavidKlineMS

@bulgogi,
You are very welcome.

Thanks!
David

bulgogi

It worked nicely. Now my app will float 2 meters away from the camera if it doesn't hit a mesh. If it hits a mesh, it will sit on the mesh facing the camera. How do I make the hologram hug the surface of the wall (parallel to the wall)?

bulgogi

Currently, depending on where I'm standing, the hologram sticks out of the wall at an angle because it's trying to face the camera. Thanks!

DavidKlineMS

@bulgogi,
Take a look at Placeable.cs in the Holograms 230 course. It handles keeping an object parallel to the wall.

The method to look at is called OrientObject.

private void OrientObject(bool alignToVerticalSurface, Vector3 surfaceNormal)
{
    Quaternion rotation = Camera.main.transform.localRotation;

    // If the user's gaze does not intersect with the Spatial Mapping mesh,
    // orient the object towards the user.
    if (alignToVerticalSurface && (PlacementSurface == PlacementSurfaces.Vertical))
    {
        // We are placing on a vertical surface.
        // If the normal of the Spatial Mapping mesh indicates that the
        // surface is vertical, orient parallel to the surface.
        if (Mathf.Abs(surfaceNormal.y) <= (1 - upNormalThreshold))
        {
            rotation = Quaternion.LookRotation(-surfaceNormal, Vector3.up);
        }
    }
    else
    {
        rotation.x = 0f;
        rotation.z = 0f;
    }

    gameObject.transform.rotation = rotation;
}

Thanks!
David

bulgogi

Thank you David, this worked.

However, the cube that is being created in Placeable to indicate the bounds of my Game Object is way too big causing it not to be placed on walls that should have enough space. I traced it to the following code in Awake():

// Create the object that will be used to indicate the bounds of the GameObject.
    boundsAsset = GameObject.CreatePrimitive(PrimitiveType.Cube);
    boundsAsset.transform.parent = gameObject.transform;
    boundsAsset.SetActive(false);

I wanted to add the following to determine the size of the cube:

  boundsAsset.transform.localScale = Vector3(0.1, 0.04, 0.02);

but it didn't work.

Thoughts?

Patrick

Hey Bulgogi,
One thing to try is rather than boundsAsset.tranform.parent, try boundsAsset.transform.SetParent(gameobject.transform, false);

the false will tell unity not to attempt to preserve the scale and position of the object while reparenting. Otherwise, if your parent as a really small scale the boundsAsset local scale will become really huge to compensate.

bulgogi

Thank you David and Patrick!