World/Udon Bugs & Feature Requests

Ever since I went ahead to update my world with the latest update in mind (SDK 3.9.1-beta.1], anyone trying to join it will receive an "Unusual Client Behavior" and be kicked out of the world immediately. I tried to delete any changes done in the world in the hope to pinpoint the problem but the problem still occurred and even after downgrading to SDK 3.9.0 it still gives the error. If it helps to solve the issue, I noticed that messing with my PlayerObject pool (despite the fact I have not touched it once for the update) and removing then adding back some object prevented the error from showing up. Alas when I decided to arrange it after I noticed some script were broken with the newer PlayerObject setup in the world that fixed the error, the error showed up again, even when I used the backup scene I saved that worked before, that one ALSO DIDN'T WORK. This is the world currently being affected by this issue : https://vrchat.com/home/world/wrld_37abea33-f34c-4706-8e6b-2f69e414fc5d/info I have tried everything to see if the problem came from my world but the problem feels way too random for it to be the case.

I tried this both with udon graph and udon sharp. Both times, when calling the Respawn function, the udon script throws an error and halts. It says that the reference is not set to an instance of an object, even though every time, I check, and there is an object with a VRCObjectSync attached to it that Respawn() is called from. And Respawn() is called from the VRCObjectSync, and not the GameObject. This is the error I get from udon graph: [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 'VRCSDK3ComponentsVRCObjectSync.__Respawn__SystemVoid'. Parameter Addresses: 0x00000000 Object reference not set to an instance of an object ---------------------- Program Counter was at: 28 ---------------------- Stack Dump: ---------------------- Heap Dump: 0x00000000: Microphone (VRC.SDK3.Components.VRCObjectSync) 0x00000001: Microphone (VRC.SDK3.Components.VRCObjectSync) 0x00000002: VRCSDK3ComponentsVRCObjectSync.__Respawn__SystemVoid ---------------------- Inner Exception: ---> VRC.Udon.VM.UdonVMException: An exception occurred during EXTERN to 'VRCSDK3ComponentsVRCObjectSync.__Respawn__SystemVoid'. Parameter Addresses: 0x00000000 ---> System.NullReferenceException: Object reference not set to an instance of an object at VRC.SDK3.ClientSim.ClientSimObjectSyncHelper.RespawnObject (VRC.SDK3.Components.VRCObjectSync sync) [0x00000] in .\Packages\com.vrchat.worlds\Integrations\ClientSim\Runtime\Helpers\ClientSimObjectSyncHelper.cs:18 at VRC.SDK3.Components.VRCObjectSync.Respawn () [0x00009] in <6ff4ff48394b436282bb70dc0ff277c2>:0 at VRC.Udon.Wrapper.Modules.ExternVRCSDK3ComponentsVRCObjectSync.__Respawn__SystemVoid (VRC.Udon.Common.Interfaces.IUdonHeap heap, System.Span`1[T] parameterAddresses) [0x0001d] in <b001fa9908f1453c979dae8b67f4c4f7>:0 at VRC.Udon.VM.UdonVM.Interpret () [0x00273] in <62e4a0d35446446b8fa1f8e5755bcfaa>:0 --- End of inner exception stack trace --- at VRC.Udon.VM.UdonVM.Interpret () [0x0033c] in <62e4a0d35446446b8fa1f8e5755bcfaa>:0 --- End of inner exception stack trace --- at VRC.Udon.VM.UdonVM.Interpret () [0x00436] in <62e4a0d35446446b8fa1f8e5755bcfaa>:0 at VRC.Udon.UdonBehaviour.RunProgram (System.UInt32 entryPoint) [0x00063] in .\Packages\com.vrchat.worlds\Runtime\Udon\UdonBehaviour.cs:1098 UnityEngine.Debug:LogError (object,UnityEngine.Object) VRC.Core.Logger:LogError (string,string,UnityEngine.Object) VRC.Udon.UdonBehaviour:RunProgram (uint) (at ./Packages/com.vrchat.worlds/Runtime/Udon/UdonBehaviour.cs:1112) VRC.Udon.UdonBehaviour:RunEvent (string) (at ./Packages/com.vrchat.worlds/Runtime/Udon/UdonBehaviour.cs:1306) VRC.Udon.UdonBehaviour:ManagedUpdate () (at ./Packages/com.vrchat.worlds/Runtime/Udon/UdonBehaviour.cs:551) VRC.Udon.UdonManager:Update () (at ./Packages/com.vrchat.worlds/Runtime/Udon/UdonManager.cs:354)

After Aries sent me this blog post https://seriot.ch/projects/parsing_json.html#2 I decided to check VRCJson against a popular test suite. I found too many issues to include in one post, so I'll be focusing on what I think is most important. The fact that exceptions can bubble up from "Try" methods and crash UdonBehaviours pretty much completely defeats the entire purpose of "Try". Here are three cases where this happens: ["a = IndexOutOfRangeException: Index was outside the bounds of the array. [] = IndexOutOfRangeException: Index was outside the bounds of the array. {"a":"b","a":"c"} = ArgumentException: An item with the same key has already been added. Key: a Please just return false instead of crashing the behaviour. If you want to do more than that then you could solve pretty much all the issues with VRCJson by internally using a real RFC 8259 compliant JSON parser and then handle boxing to and from DataToken when it leaves or enters Udon.

When serializing in VRCJson with JsonExportType set to Minify, the output contains unnecessary whitespace. To save data size, it would be better if no whitespace was included when Minify is specified. var j = new DataDictionary(); j["e1"] = 1; j["e2"] = 2; if (VRCJson.TrySerializeToJson(j, JsonExportType.Minify, out var res)) { Debug.Log(res); } Result: {"e1": 1, "e2": 2}

I noticed this bug when I tried to set a value that could not be represented as a float. Shader.SetGlobalInt() is cast to float internally, so Shader.SetGlobalInteger() needs to be used.

Additional Array methods were added in https://docs.vrchat.com/v2021.4.1/docs/vrchat-202114#changes-improvements-and-fixes-1 with the accompanying canny post marked as complete https://feedback.vrchat.com/vrchat-udon-closed-alpha-feedback/p/add-more-array-methods-to-all-array-types but Array.Sort was mysteriously left out. This would be EXTREMELY useful for quickly making a deterministic list of players using GetPlayers()'s VRCPlayerApi array by playerId (and then sorting the VRCPlayerApis by playerID with Array.Sort(keys, items)). Currently in Udon that array is out of order for different clients, and individual playerIds represent their join order, rather than an autofilled sequence from players leaving and joining. It would also be useful for sorting VRCPlayerApis by a world's game score for a scoreboard. Array.Sort is extremely useful because, even though we don't have access to custom data structures or IComparable implementations in Udon, we can still sort things using associated arrays of intrinsic data types. And before you do the same thing that you did with the previous post, please just whitelist everything you can. Not just Array methods. Stringbuilders. Native Unity components like LODGroups. Although a rumor, I heard that ReflectionProbe endpoints weren't included for a YEAR after Udon's release because there was a blacklist for anything with 'reflection' in the name. Please consider going back through the whitelist and enabled anything and everything possible.

When a networked custom event is sent with over 1kb of data to NetworkEventTarget.Self, the next networked custom event sent from that client does not send. Instead, the 1kb+ event is replayed, but to the new event target. For example if I send a 1.5kb event MyEvent on BehaviourA to NetworkEventTarget.Self, then send an event OtherEvent on BehaviourB to NetworkEventTarget.Owner (other player), instead, the owner of BehaviourB will receive MyEvent on BehaviourA with 1.5kb of data. Here is an example world where this can be seen: https://vrchat.com/home/world/wrld_451e102f-0087-4e14-a1c0-362a26a2594b

The beta documentation U# example for Sending Events with Parameters has a compile error. The example is completely missing the first parameter of NetworkCalling.SendCustomNetworkEvent which should be (IUdonEventReceiver)this . Here's the corrected snippet: ```cs using UdonSharp; using UnityEngine; using VRC.SDK3.UdonNetworkCalling; using VRC.Udon.Common.Interfaces; public class EnumDefaultTest : UdonSharpBehaviour { public override void Interact() { NetworkCalling.SendCustomNetworkEvent((IUdonEventReceiver)this, NetworkEventTarget.All, nameof(PrintMessage), "VRCat", 11); } [NetworkCallable] public void PrintMessage(string name, int age) { Debug.Log($"Congratulations on your {age}th birthday, {name}!"); } } ```

Right now OnInputMethodChanged only get called if well input method changed, but I think I would make sense to have it called once to let the world figure out the user input and switch any logic without having to manually do it with GetLastUsedInputMethod()

Udon variables that are synched are able to remove their header costs for every other instance of the same variable type. This only works if the variables end up next to eachother though when serializing. The problem is that the variables are sorted by their name, instead of their type, which leads to variables not ending up next to eachother properly. This leads to unnecessary extra header costs. EXAMPLE 1 [UdonSynced] public short a = 0; //(2 byte header, 2 byte data) [UdonSynced] public short c = 0; //(2 byte header, 2 byte data) [UdonSynced] public bool b = false; //(1 byte header, 1 byte data) EXAMPLE 2 [UdonSynced] public short a = 0;//(2 byte header, 2 byte data) [UdonSynced] public short b = 0;//(0 byte header, 2 byte data) [UdonSynced] public bool c = false;//(1 byte header, 1 byte data)