flutter3d_backend

Which graphics backend a build draws through, chosen at compile time.

import 'package:flutter3d_backend/flutter3d_backend.dart';

final device = await openDevice(width: 1280, height: 720);

openDevice returns a GraphicsDevice from flutter3d_hardware. Neither backend appears in any signature: on a desktop or a phone the device is flutter3d_impeller's, in a browser it is flutter3d_webgl's, and the choice is a conditional export rather than a runtime branch — flutter_gpu does not compile for the web and dart:js_interop does not compile for macOS, so a file importing both could target neither.

What it does not decide

Resolution and shadow budget stay in the application. kFixedResolution tells a caller whether the backend renders to a fixed internal target — true in a browser, where a WebGL canvas resets its drawing buffer when it is resized — and what size is the game's own trade against its own scene. The three games in this repository answer it differently and each says why where the number is.

Why it is a package

The conditional import and openDevice were three files in each of three games, byte-identical in two of them down to the paragraph explaining the conditional.

flutter3d_session was the obvious home and is the wrong one: it would have to depend on both backends, and then apps/flutter3d_editor — which opens a file, changes it and writes it back, and has no browser build to choose for — would pull WebGL through it. Session stays backend-neutral, which is what lets it be mounted over a CpuDevice in its own tests.

Part of flutter3d, an independent implementation of a 3D engine for Flutter — not a fork or a binding of another engine, and not affiliated with the Flutter team. Three switchable rendering backends: Impeller via Flutter GPU, WebGL2, and a software rasteriser. glTF, OBJ and .f3d loading, six lighting models, shadows, bloom, skinning, animation, BVH culling and picking; a deterministic fixed-step game layer with collision, navigation, positional audio, and gamepad and touch input. Three example games — shooter, platformer, racing — each built on its genre package: flutter3d_game_shooter, flutter3d_game_platformer, flutter3d_game_racing. A new game starts from the editor's scaffold, which writes one from a template: flutter3d.pleion.dev/first-project/. Documentation: flutter3d.pleion.dev.