Open david-dorf opened 3 months ago
Are you talking about the unrealistic behaviour in the video, or are you talking about the physics exploding? I had a lot of issues with exploding whenever the boat would hit the water too hard. This often occured when I was trying to simulate hydrodynamic damping forces without fake damping (e.g unity's built-in linear and angular damping) with default time-steps. Still, would only happen with very large waves or big drops (see https://en.wikipedia.org/wiki/Stiff_equation).
The model isnt perfect, and the more extreme the ocean state - the less realistic it looks. It's hard to model, and this was the best I was able to implement in time for my thesis submittal 😅 . You can always tweak the parameters, but you'll only get so far.
I'm glad people are having a go with the project. Unfortunately, I totally do not have the capacity to actively maintain it. If someone finds it useful, that's great, and I'm happy to provide some advice on issues that come up.
If anyone wants to improve the physics model, the thing that's missing is some kind of "slamming force" (See Jacques kerner's article: https://www.gamedeveloper.com/programming/water-interaction-model-for-boats-in-video-games-part-2). Slamming behaviour is weird, and I didn't have time to implement a force that accounts for violent slamming-related forces. To implement this, one would have to somehow model how harshly the boat is colliding with the ocean. Kerner presents a way to do this.
Hi edvart-ros, that's a really nice project. I am interested in contributing too but I am quite new in Unity. I was searching for the TF representation on RVIZ2. How can I visualize it? Is it included in some of the example scenes?
TF is not published automatically, only sensor outputs. You could make your own URDF representing the robot (corresponding to the one in Unity) and do standard ros-side TF publishing. That's essentially what's done here: https://github.com/edvart-ros/unity_asv_sim/wiki/Setting-up-and-configuring-sensors#visualizing-the-sensor-data-in-rviz
Thanks again for making this simulator, looks great and has a lot of potential. Would be interested in contributing!
Steps to reproduce: Run with the wiki recommended version of Unity and Ubuntu 24.04.
Possibly related: Large waves seem to cause boat to sink and float in the air dramatically.
Full error log in Unity:
MissingReferenceException: The variable simplifiedMesh of Submersion doesn't exist anymore. You probably need to reassign the simplifiedMesh variable of the 'Submersion' script in the inspector. UnityEngine.Object+MarshalledUnityObject.TryThrowEditorNullExceptionObject (UnityEngine.Object unityObj, System.String parameterName) (at /home/bokken/build/output/unity/unity/Runtime/Export/Scripting/UnityEngineObject.bindings.cs:710) UnityEngine.Bindings.ThrowHelper.ThrowNullReferenceException (System.Object obj) (at /home/bokken/build/output/unity/unity/Runtime/Export/Scripting/BindingsHelpers.cs:61) UnityEngine.Mesh.get_canAccess () (at <2339a4d0488949fd9e12ae0fed749682>:0) UnityEngine.Mesh.GetAllocArrayFromChannel[T] (UnityEngine.Rendering.VertexAttribute channel, UnityEngine.Rendering.VertexAttributeFormat format, System.Int32 dim) (at /home/bokken/build/output/unity/unity/Runtime/Export/Graphics/Mesh.cs:40) UnityEngine.Mesh.GetAllocArrayFromChannel[T] (UnityEngine.Rendering.VertexAttribute channel) (at /home/bokken/build/output/unity/unity/Runtime/Export/Graphics/Mesh.cs:54) UnityEngine.Mesh.get_vertices () (at /home/bokken/build/output/unity/unity/Runtime/Export/Graphics/Mesh.cs:141) WaterInteraction.Submerged..ctor (UnityEngine.Mesh simplifiedHullMesh, System.Boolean debug) (at Assets/Scripts/Physics/Processing/SubmersionLib.cs:58) Submersion.Start () (at Assets/Scripts/Physics/Processing/Submersion.cs:37)
Screencast from 2024-07-19 19-53-15.webm