Rendering to a bitmap at runtime is useful for scenarios such as snapshot testing and rendering video encoded from data-bound files.Currently only the Android runtime provides built-in support for runtime rendering to a bitmap.
Rendering to a bitmap is not supported directly in the React runtime. For offline or server-side rendering, you can use external tools like Revideo and Remotion, both of which support Rive.
Rendering to a bitmap is done using the RenderBuffer class or the onBitmapAvailable callback in the Rive Composable.
Rendering to a bitmap was technically possible in the legacy runtime by rendering to a Canvas backed by a bitmap or by sub-classing the renderer, but it was not a built-in feature and required more effort to implement. There are no plans to retrofit this feature into the legacy runtime.