World/Udon Bugs & Feature Requests

To reproduce: Create a behaviour with ExecutionOrder -100000 Create a child of it with another behaviour with no execution order overrides Create a behaviour with ExecutionOrder -100000 and NO child objects as a control Create a new separate behaviour with ExecutionOrder +100000 Add a log to Start() to keep track of it Expected result: Behaviours with -100000 to log first Behaviours with no override to log second Behaviours with +100000 to log third What actually happens: Behaviours with -100000 and NO children log first Behaviours with no override log second Behaviours with +100000 log third Behaviours with -100000 WITH children log fourth Repro world: https://vrchat.com/home/world/wrld_f43e6a53-97c2-4a6b-88af-60612f4b3cce This also creates another large issue If you also try to disable those -100000 objects (with Default children) via the +100000 Start() method - the -100000 behaviour will enter a broken state where it will never initialize or receive any events no matter what. You can toggle them on and off after - no methods will ever fire I have created a test world that illustrates the above: https://vrchat.com/home/world/wrld_06ab5f32-ffbe-44dd-9930-b3b28074fcfd Checking the logs when loading in - you'll see a bunch of objects logging OnEnable (the ones that report withChild False ), and a bunch of Default objects which are children of other -100000 objects. Then they will all get disabled by the +100000 behaviour. Clicking the sphere enables those -100000 parents, but they never log either Start() or OnEnable

Log the bool "value" argument for InputUse. Click your mouse and release. Expected: receive "True" once, receive "False" once Actual:

"Op Division" of int node crashes VRChat.exe when the divisor is zero. However, when running in Unity editor it only stops the UdonBehaviour with appropriate error message. --- The head of crash report error.log (local testing and published world case) VRChat by VRChat [version: Unity 2018.4.20f1_008688490035] GameAssembly.dll caused an Integer Divide by Zero (0xc0000094) in module GameAssembly.dll at 0033:2102cb7d. -- The message appears in Unity editor console (running in Unity editor case) [UdonBehaviour] An exception occurred during Udon execution, this UdonBehaviour will be halted. VRC.Udon.VM.UdonVMException: The VM encountered an error! Exception Message: An exception occurred during EXTERN to 'SystemInt32.__op_Division__SystemInt32_SystemInt32__SystemInt32'. Parameter Addresses: 0x00000001, 0x00000002, 0x00000000 Attempted to divide by zero.

VRCSDK3-WORLD-2021.06.03.14.57_Public

It appears that there is a threshold that must be met when scrolling the content of a world space ScrollView which is not adjusted based on the size of the scroll view. This makes it impossible to scroll sufficiently small ScrollViews (if there are no scrollbars). In Client Sim, there is no such threshold. In-Game example: https://i.imgur.com/yQ6Fj0c.mp4 Editor example: https://i.imgur.com/Ry1QZk6.mp4

Gravity and Kinematic flags on VRCObjectSync components don't sync correctly right now and also cannot be set correctly while holding the pickup. To set gravity or kinematic flags, VRChat added two new methods for us: https://udonsharp.docs.vrchat.com/vrchat-api/#vrcobjectsync (they are supposed to behave like a synced variable) There are two bugs related to this: ~ Bug 1: ~ All you need is to create a pickup that has no gravity and then toggle the gravity flag on the VRCObjectSync component with an external button after claiming ownership. Then you let different people in the world pick up the pickup and drop it (to show their own local state). In my tests, this resulted in a pickup where the gravity flag is wildly different on each client and only syncs occasionally or not at all. They would see the pickup drop on my end, but when they pick it up it has no gravity for them. ~ Bug 2: ~ All you need is to create a pickup that has no gravity and then toggle the gravity flag on the VRCObjectSync component in OnPickupUseDown() . In my tests, this resulted in a pickup where the gravity stays enabled after the first OnPickupUseDown() and I am unable to turn gravity off again. To check gravity, the pickup is dropped. You can also just test it out here: Right setup: Bug 1 / Left setup: Bug 2 https://vrchat.com/home/world/wrld_9cefd5ec-4492-43c5-8cd3-05036c494556 Additional note: Since we only got a setter and not a getter method, we are left in the dark here when it comes to analyzing the problem. Reading out the local rigidbody state doesn't give us access to the real synced state. A getter method should be added.

Update is executed for one frame after the script is disabled. Reproduction Procedure: Prepare a U# script that outputs OnEnable(), OnDisable() and each Update() log (see image). Attach this script to the game object and play it in ClientSim. When this script (component) is enabled, it will be disabled after 3 frames and output the log of each event. The log in chronological order shows that each Update() is executed after OnDisable(). (see this video : https://twitter.com/mimyquality/status/1749001703893164421 ) This also happens when switching "enabled" from other U# scripts, etc. or when switching the active game object. It seems to have started occurring since Unity Editor was changed to Unity 2022.3.6f1. Translated with www.DeepL.com/Translator (free version)

We seem to be missing a few really basic math operations for integers. The ones I've noticed so far are modulo and power.

Components sometimes "break" in Unity 2022. They are collapsed, and expanding them reveals nothing. It affects different types of components, i.e. UdonBehaviours or MeshRenderers. It can be fixed by selecting a different game GameObject. In my world projects, it's caused by the following error: ArgumentNullException: Value cannot be null. Parameter name: unityObject VRC.Udon.Serialization.OdinSerializer.UnitySerializationUtility.SerializeUnityObject (UnityEngine.Object unityObject, VRC.Udon.Serialization.OdinSerializer.SerializationData& data, System.Boolean serializeUnityFields, VRC.Udon.Serialization.OdinSerializer.SerializationContext context) (at ./Packages/com.vrchat.worlds/Runtime/Udon/Serialization/OdinSerializer/Unity Integration/UnitySerializationUtility.cs:1031) UdonSharp.UdonSharpBehaviour.UnityEngine.ISerializationCallbackReceiver.OnBeforeSerialize () (at ./Packages/com.vrchat.worlds/Integrations/UdonSharp/Runtime/UdonSharpBehaviour.cs:272) UnityEditor.EditorApplication:Internal_CallGlobalEventHandler()

Having a method of type Tuple in a UdonSharpScript causes the Udon compiler to crash with a NullPointerException. Suggested change: Add Tuple support, or implement a proper "Tuples are not supported" error message. Code to replicate error: public class Test : UdonSharpBehaviour { (int, string) ReturnsTuple() { return(1, "two"); } }