Education

Three pieces of flutter3d exist for teaching, and they fit together.

A lab that can be checked. flutter3d_education's lab.dart runs experiments on flutter3d_sim's fixed step, which reads no clock and rolls no loose dice. A student's run is recorded as its inputs, and a server checks it by replaying those inputs in a container with no Flutter SDK, the same way a game run is verified. It is plain Dart. The first lab is a pendulum.

Two profiles, for two jobs. A laboratory that a server verifies by replay stays on SimulationProfile.deterministic, because only that profile promises the same bits on every platform, and a replay is a check only if it lands where the student's run did. SimulationProfile.accurate is for demonstration and ships poses to an observer rather than inputs to replay: it steps in doubles with adaptive integrators inside the fixed step, and promises nothing across platforms. There is a number for it. Released at 0.1 rad, a pendulum under it keeps the period its series gives to within 1e-4 over 100 periods, and its energy to within 1e-6 of the swing's (pendulum_period_test.dart in flutter3d_physics holds both numbers; it measures 1.7e-9 and 4.7e-8). The deterministic step at its default eight substeps misses the same period by 4.6e-4 and loses nearly all of the swing's energy over those 100 periods, which is why a demonstration of the physics wants the other one.

A way into a course. Its sibling flutter3d_education_lti handles an LTI 1.3 launch from a learning platform and files results back as xAPI statements. It is plain Dart as well, without a web framework, so a service that only verifies a launch or posts a grade carries nothing else, and a package of its own, so an editor or a lesson that reads an experiment carries none of its cryptography.

Something to look at. The chemistry bench is a small Flutter application on the engine: glassware turned from profiles, labels typeset in TeX and wrapped on without a decal, and liquid you can pour. It runs in this site, and its source is packages/flutter3d_education/example in the repository, the package's example. It is a scene, not yet a lab: nothing reacts, and nothing is recorded.

Where this is going #

The pendulum and the bench are two halves of what a chemistry lab needs: a step that can be replayed and checked, and a bench that looks like one. Joining them, so that a titration on the bench is a recorded run a server can mark, is the next piece.