Issue with BlobAsset Construction and Array Lengths

Entity Component System (ECS)
,
1

I am trying to use Blob in my code and encountered an issue. Here is the problem I’m facing:

In my code, I have a struct called BlobNavNode which contains several fields, including BlobArray Vertex, BlobArray ConnectionIndex, and BlobArray ConnectionCost. I am using the BlobBuilder to construct a BlobAsset containing an array of BlobNavNode structs.

However, when I inspect the constructed BlobAsset at runtime, I noticed that the lengths of the ConnectionCost, ConnectionIndex, and Vertex arrays within each BlobNavNode are all zero. This is unexpected because I specified the lengths for these arrays during construction.

Here is a snippet of my code:

// ...

var nodeBuilder = new BlobBuilder(Allocator.Temp);
ref var nodeData = ref nodeBuilder.ConstructRoot<BlobArray<BlobNavNode>>();
var nodeArrayBuilder = nodeBuilder.Allocate(ref nodeData, nodes.Count);

for (var index = 0; index < nodes.Count; index++)
{
    var node = nodes[index];
    ref var blobNode = ref nodeBuilder.ConstructRoot<BlobNavNode>();

    // Set fields of blobNode...

    nodeBuilder.Construct(ref blobNode.ConnectionCost, node.connectionCost);
    nodeBuilder.Construct(ref blobNode.ConnectionIndex, node.connectionIndex);
    nodeBuilder.Construct(ref blobNode.Vertex, node.vertex);

    nodeArrayBuilder[index] = blobNode;
}

// ...

I’m not sure why the lengths of these arrays are not being set correctly. Any insights or suggestions on how to resolve this issue would be greatly appreciated.

Thank you!

2

Don’t call ConstructRoot on BlobNavNode since that isn’t actually a root of your blob.

3

The problem has been resolved.

4

I need a BlobArray of BlobNavNode. Each BlobNavNode needs to be constructed individually. If I don’t do it this way, I receive a prompt suggesting to do so.

The problem has been resolved.
The issue was caused by the order of construction in Construct.