Automatic merge of T1.5.1-684-gc6e0de1c4 and 8 pull requests

- Pull request #570 at c59c788: Experimental glTF 2.0 support with PBR lighting
- Pull request #839 at d00beb9: First phase of https://blueprints.launchpad.net/or/+spec/additional-cruise-control-parameters
- Pull request #865 at a1318b5: Dispatcher window improvements
- Pull request #874 at f8dbeab: Dynamic brake controller refactoring
- Pull request #875 at 43bf33e: Bug fix for https://bugs.launchpad.net/or/+bug/2036346 Player train switching doesn't work with 3D cabs
- Pull request #876 at f92de76: docs: add source for documents previously on website to source Documentation folder
- Pull request #878 at b13e6ab: Implement Polach Adhesion
- Pull request #883 at aac4d3f: SwitchPanel disconnect/connect handling

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/PowerTransmissions/Axle.cs

@@ -904,15 +904,16 @@ void Integrate(float elapsedClockSeconds)
             // Points are 1 = (0, upperLimit) and 2 = (threshold, lowerLimit)
 
             var upperLimit = 130;
-            var lowerLimit = 10;
+            var lowerLimit = 1;
             var AdhesGrad = ((upperLimit - lowerLimit) / (WheelSlipThresholdMpS - 0));
             var targetNumOfSubstepsPS = Math.Abs((AdhesGrad * SlipSpeedMpS) + lowerLimit);
             if (float.IsNaN((float)targetNumOfSubstepsPS)) targetNumOfSubstepsPS = 1;
             //                 Trace.TraceInformation("Grad - {0} AdhesGrad {1} SlipSpeedMps {2} Threshold {3}", temp, AdhesGrad, SlipSpeedMpS, WheelSlipThresholdMpS);
 
-            if (targetNumOfSubstepsPS > NumOfSubstepsPS) // increase substeps
+            //  if (targetNumOfSubstepsPS > NumOfSubstepsPS && Math.Abs(integratorError) > Math.Max((Math.Abs(SlipSpeedMpS) - 1) * 0.01, 0.001)) // increase substeps
+            if (targetNumOfSubstepsPS > NumOfSubstepsPS && Math.Abs(integratorError) > Math.Max((Math.Abs(SlipSpeedMpS) - 1) * 0.01, 0.001)) // increase substeps
             {
-                if (--waitBeforeSpeedingUp <= 0) //wait for a while before speeding up the integration
+                if (--waitBeforeSpeedingUp <= 0 ) //wait for a while before speeding up the integration
                 {
                     NumOfSubstepsPS += 5;
                     waitBeforeSpeedingUp = 5;      //not so fast ;)
@@ -923,14 +924,19 @@ void Integrate(float elapsedClockSeconds)
                 NumOfSubstepsPS -= 5;
                 waitBeforeSpeedingUp = 5;
             }
+            else if (Math.Abs(integratorError) < 0.005)
+            {
+                NumOfSubstepsPS -= 2;
+                waitBeforeSpeedingUp = 5;
+            }
 
             if (NumOfSubstepsPS < lowerLimit)
                 NumOfSubstepsPS = lowerLimit;
 
             if (NumOfSubstepsPS > upperLimit)
                 NumOfSubstepsPS = upperLimit;        
 
-      //      Trace.TraceInformation("Grad - {0} AdhesGrad {1} SlipSpeedMps {2} Threshold {3} NumStepsPS {4}", targetNumOfSubstepsPS, AdhesGrad, SlipSpeedMpS, WheelSlipThresholdMpS, NumOfSubstepsPS);
+ //          Trace.TraceInformation("Grad - {0} AdhesGrad {1} SlipSpeedMps {2} Threshold {3} NumStepsPS {4} Error {5}", targetNumOfSubstepsPS, AdhesGrad, SlipSpeedMpS, WheelSlipThresholdMpS, NumOfSubstepsPS, integratorError);
 
             double dt = elapsedClockSeconds / NumOfSubstepsPS;
             double hdt = dt / 2;