Unable to set the animation to specific frame / duration

[DoBa89]

Description

With the current version of Rive (^0.8.4) i'm not able to able to control an animation anymore. In the a previous version, the following code would have set the animation to specific frame/point in time.

riveController = SimpleAnimation('Gesamt');
riveController.apply(riveController.instance!.animation.context, time);

Source .riv/.rev file

header.riv.zip

Expected behavior

The animation should be set to the specific frame/point in time.

Device & Versions (please complete the following information)

• Device: [iOS Simulator]
• OS: [iOS 15.4]

Flutter 3.0.0 • channel stable • https://github.com/flutter/flutter.git
Framework • revision ee4e09cce0 (3 weeks ago) • 2022-05-09 16:45:18 -0700
Engine • revision d1b9a6938a
Tools • Dart 2.17.0 • DevTools 2.12.2

[mikerreed]

Here was my repo:

1. Modify our simple_animation.dart (in our 'examples' folder from our SDK). I copied your file ('header.riv') into our examples/assets folder.

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Simple Animation'),
      ),
      body: const Center(
//        child: RiveAnimation.network(
//          'https://cdn.rive.app/animations/vehicles.riv',
        child: RiveAnimation.asset(
          'assets/header.riv',
          animations: ['Gesamt'],
          fit: BoxFit.cover,
        ),
      ),
    );
  }

Then I modified lib/src/controllers/simple_controller.dart to set the time, instead of calling advance().

    _instance!
      ..animation.apply(_instance!.time, coreContext: artboard, mix: mix)
      ..time = 1.859;
//      ..advance(elapsedSeconds);

Then I ran the example app included in our SDK, and chose 'Simple Animation'. This is what it drew.

Which appears to be correct for that time value.

[HayesGordon]

Hi all, there is a similar question here: https://github.com/rive-app/rive-flutter/issues/165

And similar for testing, here: https://github.com/rive-app/rive-flutter/issues/162

There may have been an issue with apply but it should be working fine now. Note however, that apply does not set the animation to a particular frame/duration. Instead it advances the animation by that duration. For example if you call:

// initial time is 0
controller.apply(controller.instance!.animation.context, 1); // advances 1 second, now at 1
controller.apply(controller.instance!.animation.context, 2); // advances 2 seconds, now at 3

Each call will add time to the animation.

If you want to be sure you're setting the time to a particular duration you should first call reset, which will set the time back to 0.

controller.reset(); // time now at 0
controller.apply(controller.instance!.animation.context, 1); // advances 1 second, now at 1

You could alternatively create your own AnimationController by extending RiveAnimationController with custom logic that advances the animation as needed - as suggested by @mikerreed

Closing this for now, but feel free to reopen with suggestions/issues