How can i render metal in swiftui?

To render Metal in SwiftUI, you can use shaders written in the Metal Shading Language. Here's a step-by-step guide based on the information from the WWDC session "Create custom visual effects with SwiftUI":

1. Write a Shader in Metal: Shaders are small programs that run on the GPU to calculate rendering effects. These shaders are written in the Metal Shading Language. For example, you might have a shader function like this in your Metal file:

   kernel void ripple(texture2d<float, access::read> inTexture [[texture(0)]],
                      texture2d<float, access::write> outTexture [[texture(1)]],
                      uint2 gid [[thread_position_in_grid]]) {
       // Shader code to create a ripple effect
   }
   

2. Instantiate the Shader in SwiftUI: In SwiftUI, you can instantiate a shader by calling a function with its name on the shader library. You can also pass additional parameters to your shader function, such as colors, numbers, or images.

   let shader = ShaderLibrary.default.makeFunction(name: "ripple")
   

3. Apply the Shader to a View: Use the layerEffect view modifier to apply the shader to a SwiftUI view. SwiftUI will call your shader function for every pixel of the view.

   struct ContentView: View {
       var body: some View {
           Image("example")
               .layerEffect(shader, maxSampleOffset: .zero)
       }
   }
   

4. Create a View Modifier for Custom Effects: You can create a custom view modifier to expose the parameters of the shader function to SwiftUI.

   struct RippleModifier: ViewModifier {
       var shader: Shader
       var parameters: [String: Any]
   
       func body(content: Content) -> some View {
           content.layerEffect(shader, parameters: parameters)
       }
   }
   

For more detailed information, you can refer to the Create custom visual effects with SwiftUI (19:40) session from WWDC 2024.

Relevant Sessions

• Create custom visual effects with SwiftUI
• Bring your iOS or iPadOS game to visionOS