Miniature Map

cdor

Hi,

I'm using Spatial Mapping and Spatial Processing prefabs present in Holograms 230. I scan a room for 10 seconds and then once I have the mesh I make a copy of it using Instantiate and setting the scale of the new mesh to 1/7 of the original one to make a miniature version of the original scanned space.

When I run the code in Unity in editor mode, loading a space that was previously saved (as detailed in Holograms 230) I see that the miniature map looks exactly the same as the original one. Nevertheless, when I do this in real-time on the Hololens the copied mini mesh doesn't match the original mesh scanned through Spatial Mapping (seems like the triangles don't get copied in the right location).

Any ideas why this could be? I'm including pictures but it's a bit hard to see.

Thank you!

Patrick

Hi Cdor,
A couple of things might trip you up here.
First, if you are instantiating the original spatial mapping object, I would guess that a world anchor gets attached to the new object. You need to remove that world anchor before changing the transform of the object. To be honest, I would not clone the original object, but instead instantiate a prefab that has a meshfilter and meshrenderer, and clone the vertices.

Second, you likely need to transform your vertices based on the Mesh Filter. On the HoloLens the vertices of the meshes are relative to the mesh filter transform. In the Unity Editor the vertices are relative to the origin of the scene. So in the HoloLens you need to get your vertices relative to the origin of the scene. You can do so with code like (I haven't tested this, so it might need a tweak):

List<MeshFilter> MeshFilters = SpatialMappingManager.Instance.GetMeshFilters();
            for (int index = 0; index < MeshFilters.Count; index++)
            {
                MeshFilter filter = MeshFilters[index];
                Mesh source = filter.sharedMesh;
                Mesh clone = new Mesh();
                List<Vector3> verts = new List<Vector3>();
                verts.AddRange(source.vertices);

                for(int vertIndex=0; vertIndex < verts.Count; vertIndex++)
                {
                    verts[vertIndex] = filter.transform.TransformPoint(verts[vertIndex]);
                }

                clone.SetVertices(verts); 
                clone.SetTriangles(source.triangles, 0);
GameObject nextMiniMap = Instantiate(MiniMapPrefabMesh); 
nextMiniMap.GetComponent<MeshFilter>().sharedMesh = clone;

            }

Patrick

Hi Cdor,
A couple of things might trip you up here.
First, if you are instantiating the original spatial mapping object, I would guess that a world anchor gets attached to the new object. You need to remove that world anchor before changing the transform of the object. To be honest, I would not clone the original object, but instead instantiate a prefab that has a meshfilter and meshrenderer, and clone the vertices.

Second, you likely need to transform your vertices based on the Mesh Filter. On the HoloLens the vertices of the meshes are relative to the mesh filter transform. In the Unity Editor the vertices are relative to the origin of the scene. So in the HoloLens you need to get your vertices relative to the origin of the scene. You can do so with code like (I haven't tested this, so it might need a tweak):

List<MeshFilter> MeshFilters = SpatialMappingManager.Instance.GetMeshFilters();
            for (int index = 0; index < MeshFilters.Count; index++)
            {
                MeshFilter filter = MeshFilters[index];
                Mesh source = filter.sharedMesh;
                Mesh clone = new Mesh();
                List<Vector3> verts = new List<Vector3>();
                verts.AddRange(source.vertices);

                for(int vertIndex=0; vertIndex < verts.Count; vertIndex++)
                {
                    verts[vertIndex] = filter.transform.TransformPoint(verts[vertIndex]);
                }

                clone.SetVertices(verts); 
                clone.SetTriangles(source.triangles, 0);
GameObject nextMiniMap = Instantiate(MiniMapPrefabMesh); 
nextMiniMap.GetComponent<MeshFilter>().sharedMesh = clone;

            }

water_99

@Patrick said:
Hi Cdor,
A couple of things might trip you up here.
First, if you are instantiating the original spatial mapping object, I would guess that a world anchor gets attached to the new object. You need to remove that world anchor before changing the transform of the object. To be honest, I would not clone the original object, but instead instantiate a prefab that has a meshfilter and meshrenderer, and clone the vertices.

Second, you likely need to transform your vertices based on the Mesh Filter. On the HoloLens the vertices of the meshes are relative to the mesh filter transform. In the Unity Editor the vertices are relative to the origin of the scene. So in the HoloLens you need to get your vertices relative to the origin of the scene. You can do so with code like (I haven't tested this, so it might need a tweak):

List<MeshFilter> MeshFilters = SpatialMappingManager.Instance.GetMeshFilters();
            for (int index = 0; index < MeshFilters.Count; index++)
            {
                MeshFilter filter = MeshFilters[index];
                Mesh source = filter.sharedMesh;
                Mesh clone = new Mesh();
                List<Vector3> verts = new List<Vector3>();
                verts.AddRange(source.vertices);
            
                for(int vertIndex=0; vertIndex < verts.Count; vertIndex++)
                {
                    verts[vertIndex] = filter.transform.TransformPoint(verts[vertIndex]);
                }

                clone.SetVertices(verts); 
                clone.SetTriangles(source.triangles, 0);
GameObject nextMiniMap = Instantiate(MiniMapPrefabMesh); 
nextMiniMap.GetComponent<MeshFilter>().sharedMesh = clone;
              
            }

do you have the complete code ,thankyou very much