Draft: Feature/wheel terrain

AGXUnity/ContactMaterial.cs

@@ -128,6 +128,7 @@ public FrictionModel FrictionModel
     /// Get or set Young's modulus of this contact material.
     /// </summary>
     [ClampAboveZeroInInspector]
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "This specifies the stiffness of the contact between the interacting geometries/bodies" )]
     public float YoungsModulus
     {
@@ -150,6 +151,7 @@ public float YoungsModulus
     /// Get or set surface viscosity of this contact material.
     /// </summary>
     [ClampAboveZeroInInspector( true )]
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "The viscosity of a surface material is the same thing as compliance but for friction in contacts" )]
     public Vector2 SurfaceViscosity
     {
@@ -174,6 +176,7 @@ public Vector2 SurfaceViscosity
     /// Get or set friction coefficients of this contact material.
     /// </summary>
     [ClampAboveZeroInInspector( true )]
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "The coefficients of friction in the friction frame (default: world frame)" )]
     public Vector2 FrictionCoefficients
     {
@@ -198,6 +201,7 @@ public Vector2 FrictionCoefficients
     /// Get or set restitution of this contact material.
     /// </summary>
     [ClampAboveZeroInInspector( true )]
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "This defines the \"bounciness\" of a contact." )]
     public float Restitution
     {
@@ -242,6 +246,7 @@ public float Damping
     /// Adhesive force of the contacts with this contact material.
     /// </summary>
     [ClampAboveZeroInInspector( true )]
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "Determines a force used for keeping colliding objects together" )]
     public float AdhesiveForce
     {
@@ -266,6 +271,7 @@ public float AdhesiveForce
     /// at higher overlap, the (usual) contact force.
     /// </summary>
     [ClampAboveZeroInInspector( true )]
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "allowed overlap from surface for resting contact. At this overlap, no force is applied. At lower overlap, the adhesion force will work, at higher overlap, the (usual) contact force" )]
     public float AdhesiveOverlap
     {
@@ -287,6 +293,7 @@ public float AdhesiveOverlap
     /// <summary>
     /// Enable/disable contact area approach of contacts using this contact material.
     /// </summary>
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "If set to “true”, an approximation to the contact area will be geometrically computed for each contact involving this contact material. For each contact, its area will then be evenly distributed between its contact points. The contact compliance will be scaled with the inverse of the area for each contact point." )]
     public bool UseContactArea
     {
@@ -308,6 +315,7 @@ public bool UseContactArea
     /// <summary>
     /// Contact reduction mode, default Geometry.
     /// </summary>
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( " Specifies at which level the contact reduction algorithm should be run. None, Geometry, or Geometry and Rigidbody" )]
     public ContactReductionType ContactReductionMode
     {
@@ -329,6 +337,7 @@ public ContactReductionType ContactReductionMode
     /// <summary>
     /// Contact reduction level when contact reduction is enabled (ContactReductionMode != None).
     /// </summary>
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "Contact reduction level when contact reduction is enabled (ContactReductionMode != None)" )]
     public ContactReductionLevelType ContactReductionLevel
     {
@@ -362,6 +371,7 @@ public ContactReductionLevelType ContactReductionLevel
     /// The primary (x) friction coefficient is used along the wire and the secondary (y) is
     /// along the contact edge on the object the wire interacts with.
     /// </summary>
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [ClampAboveZeroInInspector( true )]
     [Tooltip( "Wire friction coefficients of this contact material, used by the contact nodes on a wire. The primary (x) friction coefficient is used along the wire and the secondary (y) is along the contact edge on the object the wire interacts with." )]
     public Vector2 WireFrictionCoefficients
@@ -377,6 +387,8 @@ public Vector2 WireFrictionCoefficients
       }
     }
 
+    private bool IsNotTerrainWheelForceModel => (FrictionModel != null) ? FrictionModel.IsNotTerrainWheelForceModel : true;
+
     public ContactMaterial RestoreLocalDataFrom( agx.ContactMaterial contactMaterial )
     {
       YoungsModulus         = Convert.ToSingle( contactMaterial.getYoungsModulus() );
@@ -478,7 +490,13 @@ protected override bool Initialize()
       m_contactMaterial = GetSimulation().getMaterialManager().getOrCreateContactMaterial( m1, m2 );
 
       if ( FrictionModel != null ) {
-        m_contactMaterial.setFrictionModel( FrictionModel.GetInitialized<FrictionModel>().Native );
+        if ( FrictionModel.Type == FrictionModel.EType.TerrainWheelForceModel ) {
+          agxTerrain.TerrainWheel.configureContactMaterial( m_contactMaterial );
+        }
+        else {
+          m_contactMaterial.setFrictionModel( FrictionModel.GetInitialized<FrictionModel>().Native );
+        }
+
         // When the user changes friction model type (enum = BoxFriction, ScaleBoxFriction etc.)
         // the friction model object will create a new native instance. We'll receive callbacks
         // when this happens so we can assign it to our native contact material.

AGXUnity/FrictionModel.cs

@@ -22,7 +22,8 @@ public enum EType
       IterativeProjectedFriction = 0,
       ScaleBoxFriction,
       BoxFriction,
-      ConstantNormalForceBoxFriction
+      ConstantNormalForceBoxFriction,
+      TerrainWheelForceModel
     }
 
     public enum PrimaryDirection
@@ -86,6 +87,8 @@ public static EType FindType( agx.FrictionModel native )
     {
       if ( native == null || native.asIterativeProjectedConeFriction() != null )
         return EType.IterativeProjectedFriction;
+      else if ( native.asTerrainWheelForceModel() != null )
+        return EType.TerrainWheelForceModel;
       else if ( native.asScaleBoxFrictionModel() != null )
         return EType.ScaleBoxFriction;
       else if ( native.asConstantNormalForceOrientedBoxFrictionModel() != null )
@@ -112,6 +115,7 @@ public static EType FindType( agx.FrictionModel native )
     /// <summary>
     /// Get or set solve type of this friction model.
     /// </summary>
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
     [Tooltip( "Get or set solve type of this friction model." )]
     public ESolveType SolveType
     {
@@ -148,12 +152,14 @@ public ESolveType SolveType
     /// * Scale Box - Will attempt to scale the friction bounds throughout the solve stage.
     /// * Box - Has fixed friction bounds throughout the solve stage, performant but low accuracy. Makes a guess at the normal force to solve for friction.
     /// * Constant Normal Force Box - Like Box, but will use a provided constant normal force magnitude.
+    /// * Terrain Wheel Force Model - Special model used for cylinder / terrain frictions. Used with TerrainWheel component.
     /// </summary>
     [Tooltip( "Specifies the friction model to use for this contact materials using this asset.\n" +
               "* Iterative Projected Cone - The default model. Provides a good base model which handles anisotripic frictions better than the box models.\n" +
               "* Scale Box - Will attempt to scale the friction bounds throughout the solve stage.\n" +
               "* Box - Has fixed friction bounds throughout the solve stage, performant but low accuracy. Makes a guess at the normal force to solve for friction.\n" +
-              "* Constant Normal Force Box - Like Box, but will use a provided constant normal force magnitude." )]
+              "* Constant Normal Force Box - Like Box, but will use a provided constant normal force magnitude." +
+              "* Terrain Wheel Force Model - Special model used for cylinder / terrain frictions. Used with TerrainWheel component." )]
     public EType Type
     {
       get { return m_type; }
@@ -177,6 +183,8 @@ public EType Type
     /// Enable to mark that this friction model will be used for ContactMaterials involving track. This allows the friction frame to be set up automatically for these materials.
     /// </summary>
     [Tooltip( "Enable to mark that this friction model will be used for ContactMaterials involving track. This allows the friction frame to be set up automatically for these materials" )]
+    [DynamicallyShowInInspector( nameof( IsNotTerrainWheelForceModel ) )]
+
     public bool TrackFrictionModel { get; set; } = false;
 
     /// <summary>
@@ -186,7 +194,10 @@ public EType Type
     [SerializeField]
     private float m_normalForceMagnitude = 100.0f;
 
+    [HideInInspector]
     private bool IsConstantNormalForceModel => Type == EType.ConstantNormalForceBoxFriction;
+    [HideInInspector]
+    public bool IsNotTerrainWheelForceModel => Type != EType.TerrainWheelForceModel;
 
     /// <summary>
     /// Normal force magnitude used in ConstantNormalForceBoxFriction.
@@ -271,7 +282,10 @@ public agx.FrictionModel CreateNative( EType type,
 
       agx.FrictionModel frictionModel = null;
 
-      if ( TrackFrictionModel ) {
+      if ( type == EType.TerrainWheelForceModel) {
+        frictionModel = new agx.TerrainWheelForceModel();        
+      }
+      else if ( TrackFrictionModel ) {
         frictionModel = type switch
         {
           EType.IterativeProjectedFriction => new agxVehicle.TrackIterativeProjectedConeFrictionModel( Convert( solveType ) ),