Hot reload features in Meta Spatial Editor

1. In the [versions] block of your libs.versions.toml file, add a variable called spatialsdk if there isn’t one already.

    spatialsdk = "0.8.1"
   
2. In the [libraries] block, add the hot reload library.

    meta-spatial-sdk-hotreload = { group = "com.meta.spatial", name = "meta-spatial-sdk-hotreload", version.ref = "spatialsdk" }
   
3. In the dependencies {} block of app/build.gradle.kts, add the new dependency.

     dependencies {
        implementation(libs.meta.spatial.sdk.hotreload) }
   
4. In the spatial {} block, add the appropriate config options. Note: this step is only needed for the Gradle Plugin based hot reload.

    spatial {
        hotReload {
            appPackage.set("com.your.package")
            appMainActivity.set("com.your.package.YourActivity")
            assetsDir.set(File("src/main/assets"))
        }
    }
   
5. In your app’s main activity file, register HotReloadFeature.

    class MyActivity : AppSystemActivity() {
    override fun registerFeatures(): List<SpatialFeature> {
     return listOf(
         ... // other features here
         HotReloadFeature(this))
   } }
   
   

1. Connect your device.
2. Install the target APK (the associated Android project) on your device.

1. Edit your project.
2. In the Meta Spatial Editor toolbar, click Send to device.
3. If you see a prompt, ensure the device is selected and the app is running. (Click Launch app).
4. Click Send.
5. Changes will be sent when the info button stops turning. View updates in the headset.

1. Ensure the hotReload Gradle task is synced by clicking Sync Project with Gradle Files in Android Studio:
   
2. Enable Configure all Gradle tasks during Gradle Sync in Android Studio settings:
   
3. Locate the hotReload Gradle task. If it’s missing, rebuild your task list during Gradle sync:
   
4. Run the hotReload Gradle task by right-clicking on it and selecting Run Sample:app:[hotReload]:
   

• At least v0.8.1 of Meta Spatial SDK.
• Custom shader setup:
  • NDK installed and specified in your app
  • shaders extension added to your spatial plugin, pointing to your shader sources
  • App compiles with shaders compiling correctly
• Shader compilation enabled:
  • Set enableShaderCompilation to true in your hotReload extension (this is the default)
  • Disable this only if you don’t want shader recompilation with hot reloading

1. Run the hot reload Gradle task (Method 2 above)
   • This launches your app on your device and listens for changes
2. Optional: Use casting to avoid wearing your headset
3. Navigate to any .vert or .frag file in your shader sources and make changes
4. Save your file
5. Watch your shaders reload instantly on your device!

private var myEntity: Entity? = null

// Not recommended pattern:

loadGLXF().invokeOnCompletion {
    val composition = glXFManager.getGLXFInfo("example_key_name")
    myEntity = composition.getNodeByName("my_node_name").entity
}

private fun loadGLXF(): Job {
    gltfxEntity = Entity.create()
    return activityScope.launch {
        glXFManager.inflateGLXF(
            Uri.parse("apk:///scenes/Composition.glxf"),
            rootEntity = gltfxEntity!!,
            keyName = "example_key_name"
        )
    }
}

// Recommended pattern:

loadGLXF { composition ->
    myEntity = composition.getNodeByName("my_node_name").entity
}

private fun loadGLXF(onLoaded: ((GLXFInfo) -> Unit) = {}): Job {
    gltfxEntity = Entity.create()
    return activityScope.launch {
        glXFManager.inflateGLXF(
            Uri.parse("apk:///scenes/Composition.glxf"),
            rootEntity = gltfxEntity!!,
            onLoaded = onLoaded
        )
    }
}

1. Locate the export Gradle task in the same list where you found the hotReload task.
2. Run the export task manually.