From d61bcae165b08d39012c4b8605416fe53d11e24a Mon Sep 17 00:00:00 2001
From: andy <andy>
Date: Wed, 2 Nov 2005 18:34:06 +0000
Subject: [PATCH] Vivian reported that the caster angle of the Hunter was
 experiencing "jitter" when the aircraft was stopped.  This is a fundamental
 characteristic of the gear model, and can't be fixed without major surgery
 (and not a small amount of blinding insight).  But we can at least clamp it
 so the value can't change unless the wheel is moving with a nontrivial
 velocity (5cm/sec in this case).

---
 src/FDM/YASim/Gear.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/FDM/YASim/Gear.cpp b/src/FDM/YASim/Gear.cpp
index f1e38a0c9..7950c2ef2 100644
--- a/src/FDM/YASim/Gear.cpp
+++ b/src/FDM/YASim/Gear.cpp
@@ -272,7 +272,11 @@ void Gear::calcForce(RigidBody* body, State *s, float* v, float* rot)
 
     if(_castering) {
         _rollSpeed = Math::sqrt(vsteer*vsteer + vskid*vskid);
-        _casterAngle = Math::atan2(vskid, vsteer);
+        // Don't modify caster angle when the wheel isn't moving,
+        // or else the angle will animate the "jitter" of a stopped
+        // gear.
+        if(_rollSpeed > 0.05)
+            _casterAngle = Math::atan2(vskid, vsteer);
         return;
     } else {
         _rollSpeed = vsteer;
-- 
2.39.5