How dynamic update the material texture in ShaderGraphMaterial?

Hello,

Yes, you can update input texture resources of a ShaderGraphMaterial using a DrawableQueue, below is a self-contained snippet that demonstrates this.

Important: The particulars of when/where/how you request and render to the nextDrawable depend on the exact use-case in your app. This snippet uses a Timer and CIContext for convenience of demonstration only, it is not intended to demonstrate a best practice for the functionality that it demonstrates.

import SwiftUI
import RealityKit
import RealityKitContent
import Combine

struct ContentView: View {
    
    let drawableQueue = try! TextureResource.DrawableQueue(.init(pixelFormat: .bgra8Unorm, width: 256, height: 256, usage: [.renderTarget, .shaderRead, .shaderWrite], mipmapsMode: .none))
    
    let context = CIContext()
    
    @State private var cancellables = Set<AnyCancellable>()
    
    var body: some View {
        RealityView { content in
            
            do {
                var dynamicMaterial = try await ShaderGraphMaterial(named: "/Root/DynamicMaterial", from: "Scene.usda", in: realityKitContentBundle)
                
                let color = CIImage(color: .red).cropped(to: CGRect(origin: .zero, size: .init(width: 256, height: 256)))
                let image = context.createCGImage(color, from: color.extent)!
                
                let resource = try await TextureResource.generate(from: image, options: .init(semantic: .color))
                                
                resource.replace(withDrawables: drawableQueue)
                
                try dynamicMaterial.setParameter(name: "DiffuseColorImageInput", value: .textureResource(resource))
                
                let box = Entity()
                box.name = "box"
                
                box.components.set(ModelComponent(mesh: .generateBox(size: 0.1), materials: [dynamicMaterial]))
                
                content.add(box)
                
            } catch {
                fatalError(error.localizedDescription)
            }
        }.task {
            
            Timer.publish(every: 0.5, on: .main, in: .common).autoconnect().sink { output in
                let t = output.timeIntervalSince1970
                let red = abs(sin(t))
                
                let color = CIImage(color: .init(red: red, green: 0, blue: 0)).cropped(to: CGRect(origin: .zero, size: .init(width: 256, height: 256)))
                
                do {
                    let nextDrawable = try drawableQueue.nextDrawable()
                    
                    context.render(color, to: nextDrawable.texture, commandBuffer: nil, bounds: color.extent, colorSpace: CGColorSpace(name: CGColorSpace.displayP3)!)
                    
                    nextDrawable.present()
                } catch {
                    print(error.localizedDescription)
                }
                
            }.store(in: &cancellables)
        }
    }
}

And here is a screenshot of the Shader Graph in Reality Composer Pro: