Where are the arms handled in the project?

[RazielMartelus96]

Hey there, im someone who tends to code a lot more minecraft plugins, but I do have an Aerospace Engineering Degree with a specialty in structural engineering, so wanted to see if I could have a wack at making the arms less likely to invert and look like ive seriously broken my arm haha.

Which parts of the project are used to handle the arms?

[DaXcess]

Hey there, the code for the arms is mostly located in VRPlayer.cs

LCVR/Player/VRPlayer.cs

Lines 238 to 341 in 610e7ad

	private IEnumerator RebuildRig()
	{
	RebuildingRig = true;
	// Temporarily disable animation controller
	var animator = GetComponentInChildren<Animator>();
	animator.runtimeAnimatorController = null;
	// Disable target movement by IK
	GetComponentsInChildren<IKRigFollowVRRig>().Do(follow => follow.enabled = false);
	yield return null;
	// ARMS ONLY RIG
	// Set up rigging
	var model = Find("ScavengerModel/metarig/ScavengerModelArmsOnly", true).gameObject;
	var modelMetarig = Find("ScavengerModel/metarig/ScavengerModelArmsOnly/metarig", true);
	Find("ScavengerModel/metarig/ScavengerModelArmsOnly/metarig/spine.003/RigArms", true);
	var rigFollow = model.GetComponent<IKRigFollowVRRig>() ?? model.AddComponent<IKRigFollowVRRig>();
	rigFollow.enabled = false;
	// Setting up the head
	rigFollow.head = mainCamera.transform;
	// Setting up the right arm
	var rightArmTarget = Find("ScavengerModel/metarig/ScavengerModelArmsOnly/metarig/spine.003/RigArms/RightArm/ArmsRightArm_target");
	rightArmTarget.localPosition = new Vector3(2.271f, 1.800556f, 1.008003f);
	rightArmTarget.localEulerAngles = new Vector3(180, 0, -78.54772f);
	rigFollow.rightHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = rightArmTarget.transform,
	vrTarget = rightHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	// Setting up the left arm
	var leftArmTarget = Find("ScavengerModel/metarig/ScavengerModelArmsOnly/metarig/spine.003/RigArms/LeftArm/ArmsLeftArm_target");
	rigFollow.leftHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = leftArmTarget.transform,
	vrTarget = leftHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	// This one is pretty hit or miss, sometimes y needs to be -0.2f, other times it needs to be -2.25f
	rigFollow.headBodyPositionOffset = new Vector3(0, -0.2f, 0);
	// Disable badges
	Find("ScavengerModel/metarig/spine/spine.001/spine.002/spine.003/LevelSticker").gameObject.SetActive(false);
	Find("ScavengerModel/metarig/spine/spine.001/spine.002/spine.003/BetaBadge").gameObject.SetActive(false);
	// FULL BODY RIG
	// Set up rigging
	var fullModel = Find("ScavengerModel", true).gameObject;
	var fullModelMetarig = Find("ScavengerModel/metarig", true);
	var fullRigFollow = fullModel.GetComponent<IKRigFollowVRRig>() ?? fullModel.AddComponent<IKRigFollowVRRig>();
	fullRigFollow.enabled = false;
	// Setting up the right arm
	var fullRightArmTarget = Find("ScavengerModel/metarig/spine/spine.001/spine.002/spine.003/RightArm_target");
	fullRigFollow.rightHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = fullRightArmTarget.transform,
	vrTarget = rightHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	// Setting up the left arm
	var fullLeftArmTarget = Find("ScavengerModel/metarig/spine/spine.001/spine.002/spine.003/LeftArm_target");
	fullRigFollow.leftHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = fullLeftArmTarget.transform,
	vrTarget = leftHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	// This one is pretty hit or miss, sometimes y needs to be 0, other times it needs to be -2.25f
	fullRigFollow.headBodyPositionOffset = new Vector3(0, 0, 0);
	yield return null;
	// Enable target movement by IK
	GetComponentsInChildren<IKRigFollowVRRig>().Do(follow => follow.enabled = true);
	// Re-enable animation controller
	animator.runtimeAnimatorController = AssetManager.localVrMetarig;
	RebuildingRig = false;
	}

And a fixed version of the arms that are no longer broken is already ready on the development version

LCVR/Source/Player/VRPlayer.cs

Lines 211 to 351 in 1bfa22f

	private void BuildVRRig()
	{
	// Reset player character briefly to allow the RigBuilder to behave properly
	bones.ResetToPrefabPositions();
	// ARMS ONLY RIG
	// Set up rigging
	var model = Find("ScavengerModel/metarig/ScavengerModelArmsOnly", true).gameObject;
	// Why are these even nonzero in the first place?
	bones.LocalMetarig.localPosition = Vector3.zero;
	bones.LocalArmsRig.localPosition = Vector3.zero;
	var rigFollow = model.GetComponent<IKRigFollowVRRig>() ?? model.AddComponent<IKRigFollowVRRig>();
	// Setting up the head
	rigFollow.head = mainCamera.transform;
	// Setting up the left arm
	bones.LocalLeftArmRig.localPosition = Vector3.zero;
	bones.LocalLeftArmRigHint.localPosition = new Vector3(-10f, -2f, -1f);
	// Disable built-in constraints since they don't support hints (fucks up the elbows)
	Destroy(bones.LocalLeftArmRig.GetComponent<ChainIKConstraint>());
	var localLeftArmConstraint = bones.LocalLeftArmRig.gameObject.AddComponent<TwoBoneIKConstraint>();
	localLeftArmConstraint.data.root = bones.LocalLeftUpperArm;
	localLeftArmConstraint.data.mid = bones.LocalLeftLowerArm;
	localLeftArmConstraint.data.tip = bones.LocalLeftHand;
	localLeftArmConstraint.data.target = bones.LocalLeftArmRigTarget;
	localLeftArmConstraint.data.hint = bones.LocalLeftArmRigHint;
	localLeftArmConstraint.data.hintWeight = 1;
	localLeftArmConstraint.data.targetRotationWeight = 1;
	localLeftArmConstraint.data.targetPositionWeight = 1;
	rigFollow.leftHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = bones.LocalLeftArmRigTarget,
	vrTarget = leftHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	// Setting up the right arm
	bones.LocalRightArmRig.localPosition = Vector3.zero;
	bones.LocalRightArmRigHint.localPosition = new Vector3(12.5f, -2f, -1f);
	// Disable built-in constraints since they don't support hints (fucks up the elbows)
	Destroy(bones.LocalRightArmRig.GetComponent<ChainIKConstraint>());
	var localRightArmConstraint = bones.LocalRightArmRig.gameObject.AddComponent<TwoBoneIKConstraint>();
	localRightArmConstraint.data.root = bones.LocalRightUpperArm;
	localRightArmConstraint.data.mid = bones.LocalRightLowerArm;
	localRightArmConstraint.data.tip = bones.LocalRightHand;
	localRightArmConstraint.data.target = bones.LocalRightArmRigTarget;
	localRightArmConstraint.data.hint = bones.LocalRightArmRigHint;
	localRightArmConstraint.data.hintWeight = 1;
	localRightArmConstraint.data.targetRotationWeight = 1;
	localRightArmConstraint.data.targetPositionWeight = 1;
	rigFollow.rightHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = bones.LocalRightArmRigTarget,
	vrTarget = rightHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	// This one is pretty hit or miss, sometimes y needs to be -0.2f, other times it needs to be -2.25f
	rigFollow.headBodyPositionOffset = new Vector3(0, -0.2f, 0);
	// Disable badges
	bones.Spine.Find("LevelSticker").gameObject.SetActive(false);
	bones.Spine.Find("BetaBadge").gameObject.SetActive(false);
	// FULL BODY RIG
	// Set up rigging
	var fullModel = Find("ScavengerModel", true).gameObject;
	bones.Metarig.localPosition = Vector3.zero;
	var fullRigFollow = fullModel.GetComponent<IKRigFollowVRRig>() ?? fullModel.AddComponent<IKRigFollowVRRig>();
	// Setting up the left arm
	bones.LeftArmRigHint.localPosition = new Vector3(-10f, -2f, -1f);
	// Disable built-in constraints since they don't support hints (fucks up the elbows)
	Destroy(bones.LeftArmRig.GetComponent<ChainIKConstraint>());
	var leftArmConstraint = bones.LeftArmRig.gameObject.AddComponent<TwoBoneIKConstraint>();
	leftArmConstraint.data.root = bones.LeftUpperArm;
	leftArmConstraint.data.mid = bones.LeftLowerArm;
	leftArmConstraint.data.tip = bones.LeftHand;
	leftArmConstraint.data.target = bones.LeftArmRigTarget;
	leftArmConstraint.data.hint = bones.LeftArmRigHint;
	leftArmConstraint.data.hintWeight = 1;
	leftArmConstraint.data.targetRotationWeight = 1;
	leftArmConstraint.data.targetPositionWeight = 1;
	fullRigFollow.leftHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = bones.LeftArmRigTarget,
	vrTarget = leftHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	// Setting up the right arm
	bones.RightArmRigHint.localPosition = new Vector3(12.5f, -2f, -1f);
	// Disable built-in constraints since they don't support hints (fucks up the elbows)
	Destroy(bones.RightArmRig.GetComponent<ChainIKConstraint>());
	var rightArmConstraint = bones.RightArmRig.gameObject.AddComponent<TwoBoneIKConstraint>();
	rightArmConstraint.data.root = bones.RightUpperArm;
	rightArmConstraint.data.mid = bones.RightLowerArm;
	rightArmConstraint.data.tip = bones.RightHand;
	rightArmConstraint.data.target = bones.RightArmRigTarget;
	rightArmConstraint.data.hint = bones.RightArmRigHint;
	rightArmConstraint.data.hintWeight = 1;
	rightArmConstraint.data.targetRotationWeight = 1;
	rightArmConstraint.data.targetPositionWeight = 1;
	fullRigFollow.rightHand = new IKRigFollowVRRig.VRMap()
	{
	ikTarget = bones.RightArmRigTarget,
	vrTarget = rightHandVRTarget.transform,
	trackingPositionOffset = Vector3.zero,
	trackingRotationOffset = Vector3.zero
	};
	fullRigFollow.headBodyPositionOffset = new Vector3(0, 0, 0);
	GetComponentInChildren<RigBuilder>().Build();
	}

The reason the arms looked broken was because apparently the game was using an IK chain constraint instead of a Two-bone constraint, even though the game had X_arm_hint in the hierarchy, making me believe the hints were actually used.

Turns out however, they weren't, so in the new version I replace the ChainIKConstraint for a TwoBoneIKContraint and that has fixed the arms since.