Motor angular decay fix.

1 files changed, 7 insertions, 4 deletions

diff --git a/OpenSim/Region/Physics/ChOdePlugin/ODEDynamics.cs b/OpenSim/Region/Physics/ChOdePlugin/ODEDynamics.cs
index c03e381..4eb3313 100644
--- a/OpenSim/Region/Physics/ChOdePlugin/ODEDynamics.cs
+++ b/OpenSim/Region/Physics/ChOdePlugin/ODEDynamics.cs
@@ -646,12 +646,15 @@ namespace OpenSim.Region.Physics.OdePlugin
 //if(frcount == 0) Console.WriteLine("V0 = {0}", angObjectVel);         
 //      Vector3 FrAaccel = m_lastAngularVelocity - angObjectVel;
 //    Vector3 initavel =  angObjectVel;         
-                // Decay Angular Motor
+                // Decay Angular Motor 1. In SL this also depends on attack rate! decay ~= 23/Attack.
+                float atk_decayfactor = 23.0f  / (m_angularMotorTimescale * pTimestep); 
+                m_angularMotorDVel -= m_angularMotorDVel / atk_decayfactor;
+                // Decay Angular Motor 2.
                 if (m_angularMotorDecayTimescale < 300.0f)
                 {
-                                float decayfactor = m_angularMotorDecayTimescale/pTimestep;
-                    Vector3 decayAmount = (m_angularMotorDVel/decayfactor);
-                    m_angularMotorDVel -= decayAmount;          
+                                float decayfactor = m_angularMotorDecayTimescale/pTimestep;                     // df = Dec / pts
+                    Vector3 decayAmount = (m_angularMotorDVel/decayfactor);                             // v-da = v-Dvel / df  = v-Dvel * pts / Dec
+                    m_angularMotorDVel -= decayAmount;                                                          // v-Dvel = v-Dvel - (v-Dvel / df  = v-Dvel * pts / Dec)
                 
                                 if (m_angularMotorDVel.ApproxEquals(Vector3.Zero, 0.01f))
                                 {