/// Collsion algorithm based on a paper of J. Shane Sui and John A. Hirshey II:
/// "A New Analytical Tire Model for Vehicle Dynamic Analysis" presented at 2001 MSC User Meeting
public static bool DiscTerrainCollisionEnvelope(
ChTerrain terrain, ///< [in] reference to terrain system
ChVector disc_center, ///< [in] global location of the disc center
ChVector disc_normal, ///< [in] disc normal, expressed in the global frame
double disc_radius, ///< [in] disc radius
ChFunction_Recorder areaDep, ///< [in] lookup table to calculate depth from intersection area
ref ChCoordsys contact, ///< [out] contact coordinate system (relative to the global frame)
ref double depth ///< [out] penetration depth (positive if contact occurred)
)
{
return(false);
}
public double m_stepsize; //< tire integration step size (if applicable)
/// Utility function to construct a loopkup table for penetration depth as function of intersection area,
/// for a given tire radius. The return map can be used in DiscTerrainCollisionEnvelope.
public static void ConstructAreaDepthTable(double disc_radius, ref ChFunction_Recorder areaDep)
{
const UInt64 n_lookup = 90;
double depMax = disc_radius; // should be high enough to avoid extrapolation
double depStep = depMax / (double)(n_lookup - 1);
for (UInt64 i = 0; i < n_lookup; i++)
{
double dep = depStep * (double)(i);
double alpha = 2.0 * Math.Acos(1.0 - dep / disc_radius);
double area = 0.5 * disc_radius * disc_radius * (alpha - Math.Sin(alpha));
areaDep.AddPoint(area, dep);
}
}
