I'm trying to render a large number of entities, it looks like each ModelEntity causes a draw call, even if you share the ModelComponent so each Entity shares the mesh and materials.
I tried to use the MeshInstanceCollection inside MeshResource to generate a large number of objects in the scene, the code works and draws many objects but the draw count is still one call per instance, this seems strange I would assume it should only be one draw call for the single entity since I have specified to use instancing in the resource.
Has anybody else successfully used instancing in RealityKit to draw a large number go Entities (maybe around 10,000) or drawn this amount of items successfully with 60fps any other way?
Here is some sample code that draws 100 cubes using instancing but still causes 100 draw calls.
func instanceTest(scene: RealityKit.Scene) {
var resource = MeshResource.generateBox(size: 0.2)
var contents = MeshResource.Contents()
contents.models = resource.contents.models
var arr: [MeshResource.Instance] = []
var matrix = matrix_identity_float4x4
matrix[3, 0] = 0.5
for i in 0..<100 {
let inst = MeshResource.Instance(id: "\(i)", model: "MeshModel", at: matrix)
arr.append(inst)
}
contents.instances = MeshInstanceCollection(arr)
let updatedResource = try? MeshResource.generate(from: contents)
let unlitMaterial = UnlitMaterial(color: .red)
let modelEntity = ModelEntity(
mesh: updatedResource!,
materials: [unlitMaterial]
)
let anchor = AnchorEntity()
anchor.addChild(modelEntity)
scene.addAnchor(anchor)
}
