Dynamically generate holograms

andrewot

Has anyone been able to dynamically generate holograms in app? I would like to be able to let the user generate his/her own holograms. I have an idea of how I can do it but I'm not sure how to implement it. I would generate a list of vertices and then somehow put a mesh over top. I am not sure if the unity platform can do that or if I need to use directx (which I don't know much about sadly).

Patrick

Yes, I've done this. This is easier in Unity, but can be done in DirectX.

In unity the basic pattern is:
on a game object that has a mesh filter and a mesh renderer,
get the mesh filter component.
the mesh filter should have a shared mesh. Get the shared mesh.
generate your vertices and indices.
apply them to the mesh.

(The last link has some examples).

HoloSheep

@andrewot there is a great creative coding series of videos that walk you through creating meshes in unity from scratch.

This video might get you started but, you may also want to watch both the 101 series and the rest of the 201 series to get a more complete picture.

As for dynamically creating Holograms in an app, if you are looking to let your user create Holograms by designing their own 3D models and the goal of your app is to be a 3D creation tool maybe even more low level than HoloStudio where the user starts off and adds vertices to create the model then programmatic creation might be the way to go.. but the more common scenarios that I would expect are the ones like HoloStudio where you give the user base parts or where the user just creates multiple instances of one or more existing Holograms.

For the scenarios where you want to give your user the ability to add existing holograms (or parts) to the scene you might want to look into instantiating Prefabs at runtime in Unity and the Instantiate method with Resources.Load:

GameObject MyNewHologram = (GameObject)Instantiate(Resources.Load("MyHologramPrefab"));

Patrick

Yes, I've done this. This is easier in Unity, but can be done in DirectX.

In unity the basic pattern is:
on a game object that has a mesh filter and a mesh renderer,
get the mesh filter component.
the mesh filter should have a shared mesh. Get the shared mesh.
generate your vertices and indices.
apply them to the mesh.

(The last link has some examples).

HoloSheep

@andrewot there is a great creative coding series of videos that walk you through creating meshes in unity from scratch.

This video might get you started but, you may also want to watch both the 101 series and the rest of the 201 series to get a more complete picture.

As for dynamically creating Holograms in an app, if you are looking to let your user create Holograms by designing their own 3D models and the goal of your app is to be a 3D creation tool maybe even more low level than HoloStudio where the user starts off and adds vertices to create the model then programmatic creation might be the way to go.. but the more common scenarios that I would expect are the ones like HoloStudio where you give the user base parts or where the user just creates multiple instances of one or more existing Holograms.

For the scenarios where you want to give your user the ability to add existing holograms (or parts) to the scene you might want to look into instantiating Prefabs at runtime in Unity and the Instantiate method with Resources.Load:

GameObject MyNewHologram = (GameObject)Instantiate(Resources.Load("MyHologramPrefab"));

andrewot

You guys are great! Thank you so much!

SashaFC

Is there a difference between dynamically creating meshes vs dynamically creating holograms?

I am trying to generate a plane by having the user set 4 vertices in the real world (using the height (y axis) of the first vertex for all the rest of them so the plane stays on that y "plane" but then using the x and z coordinates for each of the remaining vertices). I am using the world cursor's position and air tapping in order for the user to set the 4 vertices. I wrote the following code on an empty game object with a material, a mesh filter and a mesh renderer component, but no visible mesh is generated when I have set all 4 vertices. Can anyone please tell me what I'm doing wrong? I know the air taps are being recognized correctly from debugging..

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class EditPlane : MonoBehaviour {

public TempStateManager stateManager;
public TextMesh debug;
private List<Vector3> vertexHolder;
private Vector3 firstVertex;
public GameObject cursor;
private int input;
// Use this for initialization
void Start() {
    vertexHolder = new List<Vector3>();
    input = 0;
}


void OnSelect()
{
    if (stateManager.state == "setVertices")
    {

        if (input < 4)
        {
            if (input == 0)//first time
            {
                firstVertex = cursor.transform.position;//save first y position
                //add first vertex (vertex 0)
                vertexHolder.Add(firstVertex);
                Debug.Log("added first vertex");
                debug.text = "added first vertex";
            }
            else 
            {
                Vector3 newVertex = new Vector3(cursor.transform.position.x, firstVertex.y, cursor.transform.position.z);
                //add vertices 1, 2, and 3
                vertexHolder.Add(newVertex);
                Debug.Log("added subsequent vertex");
                debug.text = "added subsequent vertex";
                if(input ==3)//last input
                {
                    debug.text = "last vertex";

                    //triangles
                    int[] tri = new int[6];
                    tri[0] = 0;
                    tri[1] = 2;
                    tri[2] = 1;

                    tri[3] = 2;
                    tri[4] = 3;
                    tri[5] = 1;

                    //normals
                    Vector3[] normals = new Vector3[4];
                    normals[0] = Vector3.up;
                    normals[1] = Vector3.up;
                    normals[2] = Vector3.up;
                    normals[3] = Vector3.up;

                    Mesh mesh = new Mesh();
                    GetComponent<MeshFilter>().mesh = mesh;
                    mesh.SetVertices(vertexHolder);
                    mesh.triangles = tri;
                    mesh.normals = normals;
                    debug.text = "set mesh";



                }
            }
            input++;
        }
    }

}

}

Thanks!

stephenhodgson

Here's a Gem from the past. Probably as old as unity itself:

wiki.unity3d.com/index.php/ProceduralPrimitives

stephenhodgson

@SashaFC said:
Is there a difference between dynamically creating meshes vs dynamically creating holograms?

Essentially no, they're the same thing. A Hologram is what's rendered in front of you on device.

SashaFC

@stephenhodgson thank you!