What is the syntax for a jagged Vector3 to initialize it?

Question

How can I set each vector3 array inside of the jagged vector3[][] to 64, with out manually initializing it like so...

     Vector3[][] verts = new Vector3 [ 4 ][] {      
           new Vector3[64],
           new Vector3[64],
           new Vector3[64],
           new Vector3[64]
     };
         
    //Vector3[][] verts = new Vector3 [ 4 ][64]; 
 
     void Update () {
            verts[2] = _Mesh[0].vertices; //access the third Vector3[] of vector 3's }

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Answer by Bunny83 · Nov 18, 2017 at 03:53 AM

Uhm, use a for loop? A jagged array is not "one thing". You have the outer array which is an array of arrays and you have the inner arrays which are referenced from the outer array. By default when you just create the outer array the elements of the outer array will be "null". So there's no way around creating those nested arrays "manually".

 var verts = new Vector3[4][];
 for(int i = 0; i < verts.Length; i++)
 {
     verts[i] = new Vector3[64];
 }

However i don't quite see the reason to initialize them when you seem to plan to replace / overwrite the array with the aray that is returned from _Mesh[0].vertices.

This line does not "access" the third array but it replaces / overwrites the array:

 verts[2] = _Mesh[0].vertices;

That means the array that was referenced previously by the 3rd element will now be garbage collected. It's not recommended to read Mesh.vertices every frame. Each time you read the vertices property you will create a new array which is filled with the vertex data of the mesh.

This is a question that is lacking some background information about what you actually want to achieve.

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zachwuzhere · Nov 18, 2017 at 06:11 PM 0

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Ah, I figured I would have to loop through it, just didn't know if there was a way other than that. By access I meant to copy the vertices into the array so I can access them through the array later.

When You say it "replaces/overwrites the array", does that mean I don't need to initialize the inner arrays if it is just replacing it with the mesh's vertices?

Bunny83 zachwuzhere · Nov 18, 2017 at 11:30 PM 0

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Yes, exactly. The manually created arrays are pointless when you're going to store a different array in the elements.

$$anonymous$$eep in $$anonymous$$d that $$anonymous$$esh.vertices is not a direct access to the meshs vertex array. "vertices" is a property which has a "get" method. When you read this property Unity will actually create a new unique array.

 Vector3[] arr1 = some$$anonymous$$esh.vertices;
 Vector3[] arr2 = some$$anonymous$$esh.vertices;
 if (arr1 == arr2) // this will ALWAYS be "false"

Both arrays arr1 and arr2 contain the exact same Vector3 values but they are two seperate arrays.

$$anonymous$$icrosoft has a decent documentation on jagged arrays so you might want to check it out.

Also keep in $$anonymous$$d that the vertices array that you get from reading the property has not "connection" to the actual mesh. So changing elements in that array won't change the mesh. You would need to assign the array back to the property in order to "set" the vertices.

What is the syntax for a jagged Vector3 to initialize it?

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