ode/src/heightfield.cpp
changeset 0 2f259fa3e83a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ode/src/heightfield.cpp	Tue Feb 02 01:00:49 2010 +0200
@@ -0,0 +1,1350 @@
+// dHeightfield Collider
+//  Paul Cheyrou-Lagreze aka Tuan Kuranes 2006 Speed enhancements http://www.pop-3d.com
+//  Martijn Buijs 2006 http://home.planet.nl/~buijs512/
+// Based on Terrain & Cone contrib by:
+//  Benoit CHAPEROT 2003-2004 http://www.jstarlab.com
+//  Some code inspired by Magic Software
+
+
+#include <ode/common.h>
+#include <ode/collision.h>
+#include <ode/matrix.h>
+#include <ode/rotation.h>
+#include <ode/odemath.h>
+#include "collision_kernel.h"
+#include "collision_std.h"
+#include "collision_util.h"
+#include "heightfield.h"
+
+#define TERRAINTOL REAL(0.0f)
+
+#define dMIN(A,B)  ((A)>(B) ? B : A)
+#define dMAX(A,B)  ((A)>(B) ? A : B)
+
+
+// Three-way MIN and MAX
+#define dMIN3(A,B,C)	( (A)<(B) ? dMIN((A),(C)) : dMIN((B),(C)) )
+#define dMAX3(A,B,C)	( (A)>(B) ? dMAX((A),(C)) : dMAX((B),(C)) )
+
+#define dOPESIGN(a, op1, op2,b) \
+    (a)[0] op1 op2 ((b)[0]); \
+    (a)[1] op1 op2 ((b)[1]); \
+    (a)[2] op1 op2 ((b)[2]);
+
+#define dGeomRaySetNoNormalize(myRay, MyPoint, MyVector) {  \
+    \
+    dVector3Copy (MyPoint, myRay.final_posr->pos);   \
+    myRay.final_posr->R[2] = MyVector[0];       \
+    myRay.final_posr->R[6] = MyVector[1];       \
+    myRay.final_posr->R[10] = MyVector[2];      \
+    dGeomMoved (&myRay);                        \
+            }
+
+#define dGeomPlaneSetNoNormalize(MyPlane, MyPlaneDef) { \
+    \
+    MyPlane->p[0] = MyPlaneDef[0];  \
+    MyPlane->p[1] = MyPlaneDef[1];  \
+    MyPlane->p[2] = MyPlaneDef[2];  \
+    MyPlane->p[3] = MyPlaneDef[3];  \
+    dGeomMoved (MyPlane);           \
+                    }
+//////// dxHeightfieldData /////////////////////////////////////////////////////////////
+
+// dxHeightfieldData constructor
+dxHeightfieldData::dxHeightfieldData()
+{
+    //
+}
+
+
+// build Heightfield data
+void dxHeightfieldData::SetData( int nWidthSamples, int nDepthSamples,
+                                dReal fWidth, dReal fDepth,
+                                dReal fScale, dReal fOffset, dReal fThickness,
+                                int bWrapMode )
+{
+
+
+    // x,z bounds
+    m_fWidth = fWidth;
+    m_fDepth = fDepth;
+
+    // cache half x,z bounds
+    m_fHalfWidth = dDIV(fWidth,REAL( 2.0 ));
+    m_fHalfDepth = dDIV(fDepth,REAL( 2.0 ));
+
+    // scale and offset
+    m_fScale = fScale;
+    m_fOffset = fOffset;
+
+    // infinite min height bounds
+    m_fThickness = fThickness;
+
+    // number of vertices per side
+    m_nWidthSamples = nWidthSamples;
+    m_nDepthSamples = nDepthSamples;
+
+    m_fSampleWidth = m_fWidth / ( m_nWidthSamples - 1 );
+    m_fSampleDepth = m_fDepth / ( m_nDepthSamples - 1 );
+
+    m_fInvSampleWidth = dDIV(REAL(1.0),m_fSampleWidth);
+    m_fInvSampleDepth = dDIV(REAL(1.0),m_fSampleDepth);
+
+    // finite or repeated terrain?
+    m_bWrapMode = bWrapMode;
+}
+
+
+// recomputes heights bounds
+void dxHeightfieldData::ComputeHeightBounds()
+{
+    static int i;
+    static dReal h;
+    static dReal *data_float;
+
+    data_float = (dReal*)m_pHeightData;
+    m_fMinHeight = dInfinity;
+    m_fMaxHeight = -dInfinity;
+
+    for (i=0; i<m_nWidthSamples*m_nDepthSamples; i++)
+    {
+       h = data_float[i];
+       if (h < m_fMinHeight)	m_fMinHeight = h;
+       if (h > m_fMaxHeight)	m_fMaxHeight = h;
+    }
+
+    // scale and offset
+    m_fMinHeight = dMUL(m_fMinHeight,m_fScale);
+    m_fMaxHeight = dMUL(m_fMaxHeight,m_fScale);
+    m_fMinHeight += m_fOffset;
+    m_fMaxHeight += m_fOffset;
+
+    // add thickness
+    m_fMinHeight -= m_fThickness;
+}
+
+
+// returns whether point is over terrain Cell triangle?
+bool dxHeightfieldData::IsOnHeightfield  ( const dReal * const CellOrigin, const dReal * const pos,  const bool isABC) const
+{
+    {
+        const dReal MaxX = CellOrigin[0] + m_fSampleWidth;
+        const dReal TolX = dMUL(m_fSampleWidth,TERRAINTOL);
+        if ((pos[0]<CellOrigin[0]-TolX) || (pos[0]>MaxX+TolX))	
+            return false;
+    }
+
+    {
+        const dReal MaxZ = CellOrigin[2] + m_fSampleDepth;
+        const dReal TolZ = dMUL(m_fSampleDepth,TERRAINTOL);
+        if ((pos[2]<CellOrigin[2]-TolZ) || (pos[2]>MaxZ+TolZ))	
+            return false;
+    }
+
+    // add X percentage position on cell and Z percentage position on cell
+    const dReal pctTotal = dMUL((pos[0] - CellOrigin[0]),m_fInvSampleWidth )
+        + dMUL((pos[2] - CellOrigin[2]),m_fInvSampleDepth);
+
+    if (isABC)
+    {
+        if (pctTotal >= REAL(1.0) + TERRAINTOL)	
+            return false;
+        else	
+            return true;
+    }
+    else if (pctTotal <= REAL(1.0) - TERRAINTOL)	
+    {
+        return false;
+    }
+    return true;
+}
+// returns whether point is over terrain Cell triangle?
+bool dxHeightfieldData::IsOnHeightfield2  ( const dReal * const CellOrigin, const dReal * const pos,  const bool isABC) const
+{
+    dReal MaxX, MinX;
+    dReal MaxZ, MinZ;
+    if (isABC)
+    {
+        // point A
+        MinX = CellOrigin[0];
+        MaxX = CellOrigin[0] + m_fSampleWidth;
+
+        MinZ = CellOrigin[2];
+        MaxZ = CellOrigin[2] + m_fSampleDepth;
+    }
+    else
+    {
+        // point D
+        MinX = CellOrigin[0] - m_fSampleWidth;
+        MaxX = CellOrigin[0];
+
+        MinZ = CellOrigin[2] - m_fSampleDepth;
+        MaxZ = CellOrigin[2];
+    }
+
+    // check if inside CELL
+    {
+        const dReal TolX = dMUL(m_fSampleWidth,TERRAINTOL);
+        if ((pos[0]<MinX-TolX) || (pos[0]>MaxX+TolX))	
+            return false;
+    }
+
+    {
+        const dReal TolZ = dMUL(m_fSampleDepth,TERRAINTOL);
+        if ((pos[2]<MinZ-TolZ) || (pos[2]>MaxZ+TolZ))	
+            return false;
+    }
+
+    // Sum up X percentage position on cell and Z percentage position on cell
+    const dReal pctTotal = dMUL((pos[0] - MinX),m_fInvSampleWidth) 
+        + dMUL((pos[2] - MinZ),m_fInvSampleDepth);
+
+    // check if inside respective Triangle of Cell
+    if (isABC)	
+    {
+        if (pctTotal >= REAL(1.0) + TERRAINTOL)	
+            return false;
+        else	
+            return true;
+    }
+    else if (pctTotal <= REAL(1.0) - TERRAINTOL)	
+    {
+        return false;
+    }
+    return true;
+}
+
+
+// returns height at given sample coordinates
+dReal dxHeightfieldData::GetHeight( int x, int z )
+{
+    static dReal h;
+    static dReal *data_float;
+
+    if ( m_bWrapMode == 0 )
+    {
+        // Finite
+        if ( x < 0 ) x = 0;
+        if ( z < 0 ) z = 0;
+        if ( x > m_nWidthSamples - 1 ) x = m_nWidthSamples - 1;
+        if ( z > m_nDepthSamples - 1 ) z = m_nDepthSamples - 1;
+    }
+    else
+    {
+        // Infinite
+        x %= m_nWidthSamples - 1;
+        z %= m_nDepthSamples - 1;
+        if ( x < 0 ) x += m_nWidthSamples - 1;
+        if ( z < 0 ) z += m_nDepthSamples - 1;
+    }
+
+    data_float = (dReal*)m_pHeightData;
+    h = data_float[x+(z * m_nWidthSamples)];
+
+    return dMUL(h,m_fScale) + m_fOffset;
+}
+
+
+// returns height at given coordinates
+dReal dxHeightfieldData::GetHeight( dReal x, dReal z )
+{
+    int nX	= dMUL( x,m_fInvSampleWidth )>>QFACTOR;
+    int nZ	= dMUL( z,m_fInvSampleDepth )>>QFACTOR;
+
+    dReal dx = dMUL(( x - ( nX * m_fSampleWidth ) ),m_fInvSampleWidth);
+    dReal dz = dMUL(( z - ( nZ * m_fSampleDepth ) ),m_fInvSampleDepth);
+
+
+
+    dReal y, y0;
+
+    if ( dx + dz < REAL( 1.0 ) )
+    {
+        y0 = GetHeight( nX, nZ );
+
+        y = y0 + dMUL(( GetHeight( nX + 1, nZ ) - y0 ),dx)
+            + dMUL(( GetHeight( nX, nZ + 1 ) - y0 ),dz);
+    }
+    else
+    {
+        y0 = GetHeight( nX + 1, nZ + 1 );
+
+        y = y0	+ dMUL(( GetHeight( nX + 1, nZ ) - y0 ),( REAL(1.0f) - dz )) +
+            dMUL(( GetHeight( nX, nZ + 1 ) - y0 ),( REAL(1.0f) - dx ));
+    }
+
+    return y;
+}
+
+
+// dxHeightfieldData destructor
+dxHeightfieldData::~dxHeightfieldData()
+{
+    static dReal *data_float;
+
+
+    if ( m_bCopyHeightData )
+    {
+        data_float = (dReal*)m_pHeightData;
+        delete [] data_float;     
+    }
+}
+
+
+//////// dxHeightfield /////////////////////////////////////////////////////////////////
+
+
+// dxHeightfield constructor
+dxHeightfield::dxHeightfield( dSpaceID space,
+                             dHeightfieldDataID data,
+                             int bPlaceable )			:
+    dxGeom( space, bPlaceable ),
+    tempPlaneBuffer(0),
+    tempPlaneBufferSize(0),
+    tempTriangleBuffer(0),
+    tempTriangleBufferSize(0),
+    tempHeightBuffer(0),
+    tempHeightBufferSizeX(0),
+    tempHeightBufferSizeZ(0)
+{
+    type = dHeightfieldClass;
+    this->m_p_data = data;
+}
+
+
+// compute axis aligned bounding box
+void dxHeightfield::computeAABB()
+{
+    const dxHeightfieldData *d = m_p_data;
+
+    if ( d->m_bWrapMode == 0 )
+    {
+        // Finite
+        if ( gflags & GEOM_PLACEABLE )
+        {
+            dReal dx[6], dy[6], dz[6];
+
+            // Y-axis
+            dy[0] = dMUL( final_posr->R[ 1],d->m_fMinHeight );
+            dy[1] = dMUL( final_posr->R[ 5],d->m_fMinHeight );
+            dy[2] = dMUL( final_posr->R[ 9],d->m_fMinHeight );
+            dy[3] = dMUL( final_posr->R[ 1],d->m_fMaxHeight );
+            dy[4] = dMUL( final_posr->R[ 5],d->m_fMaxHeight );
+            dy[5] = dMUL( final_posr->R[ 9],d->m_fMaxHeight );
+
+
+            // X-axis
+            dx[0] = dMUL( final_posr->R[ 0],-d->m_fHalfWidth );
+            dx[1] = dMUL( final_posr->R[ 4],-d->m_fHalfWidth );
+            dx[2] = dMUL( final_posr->R[ 8],-d->m_fHalfWidth );
+            dx[3] = dMUL( final_posr->R[ 0],d->m_fHalfWidth );
+            dx[4] = dMUL( final_posr->R[ 4],d->m_fHalfWidth );
+            dx[5] = dMUL( final_posr->R[ 8],d->m_fHalfWidth );
+
+            // Z-axis
+            dz[0] = dMUL( final_posr->R[ 2],-d->m_fHalfDepth );
+            dz[1] = dMUL( final_posr->R[ 6],-d->m_fHalfDepth );
+            dz[2] = dMUL( final_posr->R[10],-d->m_fHalfDepth );
+            dz[3] = dMUL( final_posr->R[ 2],d->m_fHalfDepth );
+            dz[4] = dMUL( final_posr->R[ 6],d->m_fHalfDepth );
+            dz[5] = dMUL( final_posr->R[10],d->m_fHalfDepth );
+
+
+            // X extents
+            aabb[0] = final_posr->pos[0] +
+                dMIN3( dMIN( dx[0], dx[3] ), dMIN( dy[0], dy[3] ), dMIN( dz[0], dz[3] ) );
+            aabb[1] = final_posr->pos[0] +
+                dMAX3( dMAX( dx[0], dx[3] ), dMAX( dy[0], dy[3] ), dMAX( dz[0], dz[3] ) );
+
+            // Y extents
+            aabb[2] = final_posr->pos[1] +
+                dMIN3( dMIN( dx[1], dx[4] ), dMIN( dy[1], dy[4] ), dMIN( dz[1], dz[4] ) );
+            aabb[3] = final_posr->pos[1] +
+                dMAX3( dMAX( dx[1], dx[4] ), dMAX( dy[1], dy[4] ), dMAX( dz[1], dz[4] ) );
+
+            // Z extents
+            aabb[4] = final_posr->pos[2] +
+                dMIN3( dMIN( dx[2], dx[5] ), dMIN( dy[2], dy[5] ), dMIN( dz[2], dz[5] ) );
+            aabb[5] = final_posr->pos[2] +
+                dMAX3( dMAX( dx[2], dx[5] ), dMAX( dy[2], dy[5] ), dMAX( dz[2], dz[5] ) );
+        }
+        else
+        {
+
+            aabb[0] = -d->m_fHalfWidth;		aabb[1] = +d->m_fHalfWidth;
+            aabb[2] = d->m_fMinHeight;		aabb[3] = d->m_fMaxHeight;
+            aabb[4] = -d->m_fHalfDepth;		aabb[5] = +d->m_fHalfDepth;
+
+
+        }
+    }
+    else
+    {
+        // Infinite
+        if ( gflags & GEOM_PLACEABLE )
+        {
+            aabb[0] = -dInfinity;			aabb[1] = +dInfinity;
+            aabb[2] = -dInfinity;			aabb[3] = +dInfinity;
+            aabb[4] = -dInfinity;			aabb[5] = +dInfinity;
+        }
+        else
+        {
+            aabb[0] = -dInfinity;			aabb[1] = +dInfinity;
+            aabb[2] = d->m_fMinHeight;		aabb[3] = d->m_fMaxHeight;
+            aabb[4] = -dInfinity;			aabb[5] = +dInfinity;
+        }
+    }
+
+}
+
+
+// dxHeightfield destructor
+dxHeightfield::~dxHeightfield()
+{
+    delete [] tempTriangleBuffer;
+
+    for (unsigned int k = 0; k < tempPlaneBufferSize; k++)
+    {
+        delete tempPlaneBuffer[k];
+    }
+    delete [] tempPlaneBuffer;
+
+    resetHeightBuffer();
+}
+
+void dxHeightfield::resetHeightBuffer()
+{
+    const size_t xSize = tempHeightBufferSizeX;
+    for (size_t x = 0; xSize < x; x++)
+    {
+        delete [] tempHeightBuffer[x];
+    }
+    delete [] tempHeightBuffer;
+}
+//////// Heightfield data interface ////////////////////////////////////////////////////
+
+
+EXPORT_C dHeightfieldDataID dGeomHeightfieldDataCreate()
+{
+    return new dxHeightfieldData();
+}
+
+
+EXPORT_C void dGeomHeightfieldDataBuildCallback( dHeightfieldDataID d,
+                                       void* pUserData, dHeightfieldGetHeight* pCallback,
+                                       dReal width, dReal depth, int widthSamples, int depthSamples,
+                                       dReal scale, dReal offset, dReal thickness, int bWrap )
+{
+
+
+    // callback
+    d->m_nGetHeightMode = 0;
+    d->m_pUserData = pUserData;
+    d->m_pGetHeightCallback = pCallback;
+
+    // set info
+    d->SetData( widthSamples, depthSamples, width, depth, scale, offset, thickness, bWrap );
+
+    // default bounds
+    d->m_fMinHeight = -dInfinity;
+    d->m_fMaxHeight = dInfinity;
+}
+
+EXPORT_C void dGeomHeightfieldDataBuildSingle( dHeightfieldDataID d,
+                                     const float *pHeightData, int bCopyHeightData,
+                                     dReal width, dReal depth, int widthSamples, int depthSamples,
+                                     dReal scale, dReal offset, dReal thickness, int bWrap )
+{
+
+
+    // set info
+    d->SetData( widthSamples, depthSamples, width, depth, scale, offset, thickness, bWrap );
+    d->m_nGetHeightMode = 3;
+    d->m_bCopyHeightData = bCopyHeightData;
+
+    if ( d->m_bCopyHeightData == 0 )
+    {
+        // Data is referenced only.
+        d->m_pHeightData = pHeightData;
+    }
+    else
+    {
+        // We own the height data, allocate storage
+        d->m_pHeightData = new dReal[ d->m_nWidthSamples * d->m_nDepthSamples ];
+
+
+        // Copy data.
+        memcpy( (void*)d->m_pHeightData, pHeightData,
+            sizeof( dReal ) * d->m_nWidthSamples * d->m_nDepthSamples );
+    }
+
+    // Find height bounds
+    d->ComputeHeightBounds();
+}
+
+
+EXPORT_C void dGeomHeightfieldDataSetBounds( dHeightfieldDataID d, dReal minHeight, dReal maxHeight )
+{
+
+    d->m_fMinHeight = dMUL( minHeight,d->m_fScale ) + d->m_fOffset - d->m_fThickness;
+    d->m_fMaxHeight = dMUL( maxHeight,d->m_fScale ) + d->m_fOffset;
+}
+
+
+EXPORT_C void dGeomHeightfieldDataDestroy( dHeightfieldDataID d )
+{
+    delete d;
+}
+
+
+//////// Heightfield geom interface ////////////////////////////////////////////////////
+
+
+EXPORT_C dGeomID dCreateHeightfield( dSpaceID space, dHeightfieldDataID data, int bPlaceable )
+{
+    return new dxHeightfield( space, data, bPlaceable );
+}
+
+
+EXPORT_C void dGeomHeightfieldSetHeightfieldData( dGeomID g, dHeightfieldDataID d )
+{
+    dxHeightfield* geom = (dxHeightfield*) g;
+    geom->data = d;
+}
+
+
+EXPORT_C dHeightfieldDataID dGeomHeightfieldGetHeightfieldData( dGeomID g )
+{
+    dxHeightfield* geom = (dxHeightfield*) g;
+    return geom->m_p_data;
+}
+
+//////// dxHeightfield /////////////////////////////////////////////////////////////////
+
+
+// Typedef for generic 'get point depth' function
+typedef dReal dGetDepthFn( dGeomID g, dReal x, dReal y, dReal z );
+
+
+
+static inline bool DescendingPlaneSort(const HeightFieldPlane * const A, const HeightFieldPlane * const B)
+{
+    return ((A->maxAAAB - B->maxAAAB) > dEpsilon);
+}
+
+void dxHeightfield::sortPlanes(const size_t numPlanes)
+{
+    bool has_swapped = true;
+    do
+    {
+        has_swapped = false;//reset flag
+        for (size_t i = 0; i < numPlanes - 1; i++)
+        {
+            //if they are in the wrong order
+            if (DescendingPlaneSort(tempPlaneBuffer[i], tempPlaneBuffer[i + 1]))
+            { 
+                //exchange them
+                HeightFieldPlane * tempPlane = tempPlaneBuffer[i];
+                tempPlaneBuffer[i] = tempPlaneBuffer[i + 1];
+                tempPlaneBuffer[i + 1] = tempPlane;
+
+                //we have swapped at least once, list may not be sorted yet
+                has_swapped = true;
+            }
+        }
+    }    //if no swaps were made during this pass, the list has been sorted
+    while (has_swapped);
+}
+
+int dxHeightfield::dCollideHeightfieldZone( const int minX, const int maxX, const int minZ, const int maxZ, 
+                                           dxGeom* o2, const int numMaxContactsPossible,
+                                           int flags, dContactGeom* contact, 
+                                           int skip )
+{
+	dContactGeom *pContact = 0;
+    int  x, z;
+    // check if not above or inside terrain first
+    // while filling a heightmap partial temporary buffer
+    const unsigned int numX = (maxX - minX) + 1;
+    const unsigned int numZ = (maxZ - minZ) + 1;
+    const dReal minO2Height = o2->aabb[2];
+    const dReal maxO2Height = o2->aabb[3];
+    unsigned int x_local, z_local;
+    dReal maxY = - dInfinity;
+    dReal minY = dInfinity;
+    // localize and const for faster access
+    const dReal cfSampleWidth = m_p_data->m_fSampleWidth;
+    const dReal cfSampleDepth = m_p_data->m_fSampleDepth;
+    {
+        if (tempHeightBufferSizeX < numX || tempHeightBufferSizeZ < numZ)
+        {
+            resetHeightBuffer();
+            tempHeightBufferSizeX = numX;
+            tempHeightBufferSizeZ = numZ;
+            tempHeightBuffer = new HeightFieldVertex *[numX];
+            for ( x_local = 0; x_local < numX; x_local++)
+            {
+                tempHeightBuffer[x_local] = new HeightFieldVertex [numZ];     
+            }
+        }
+
+        dReal Xpos, Ypos;
+        Xpos = minX*cfSampleWidth;
+
+
+        for ( x = minX, x_local = 0; x_local < numX; x++, x_local++)
+        {
+            const dReal c_Xpos = Xpos;
+            HeightFieldVertex *HeightFieldRow = tempHeightBuffer[x_local];
+            Ypos = minZ * cfSampleDepth;
+            for ( z = minZ, z_local = 0; z_local < numZ; z++, z_local++)
+            {
+                const dReal h = m_p_data->GetHeight(x, z);
+                HeightFieldRow[z_local].vertex[0] = c_Xpos;
+                HeightFieldRow[z_local].vertex[1] = h;
+                HeightFieldRow[z_local].vertex[2] = Ypos;
+                
+
+                maxY = dMAX(maxY, h);
+                minY = dMIN(minY, h);
+
+
+                Ypos += cfSampleDepth;
+            }
+            Xpos += cfSampleWidth;
+        }
+        if (minO2Height - maxY > -dEpsilon )
+        {
+			//totally above heightfield
+            return 0;
+        }
+		if (minY - maxO2Height > -dEpsilon )
+		{
+			// totally under heightfield
+			pContact = CONTACT(contact, 0);
+
+			pContact->pos[0] = o2->final_posr->pos[0];
+			pContact->pos[1] = minY;
+			pContact->pos[2] = o2->final_posr->pos[2];
+
+			pContact->normal[0] = 0;
+			pContact->normal[1] = REAL(-1.0);
+			pContact->normal[2] = 0;
+
+			pContact->depth =  minY - maxO2Height;
+
+			return 1;
+		}
+    }
+    int numTerrainContacts = 0;
+    // get All Planes that could collide against.
+    dColliderFn *geomRayNCollider = 0;
+    dColliderFn *geomNPlaneCollider = 0;
+    dGetDepthFn *geomNDepthGetter = 0;
+
+    int max_collisionContact = numMaxContactsPossible;
+    switch (o2->type)
+    {
+    case dRayClass:
+        geomRayNCollider		= NULL;
+        geomNPlaneCollider	    = dCollideRayPlane;
+        geomNDepthGetter		= NULL;
+        //max_collisionContact    = 1;
+        break;
+
+    case dSphereClass:
+        geomRayNCollider		= dCollideRaySphere;
+        geomNPlaneCollider  	= dCollideSpherePlane;
+        geomNDepthGetter		= dGeomSpherePointDepth;
+        //max_collisionContact    = 3;
+        break;
+
+    case dBoxClass:
+        geomRayNCollider		= dCollideRayBox;
+        geomNPlaneCollider	    = dCollideBoxPlane;
+        geomNDepthGetter		= dGeomBoxPointDepth;
+        //max_collisionContact    = 8;
+        break;
+
+    case dCapsuleClass:
+        geomRayNCollider		= dCollideRayCapsule;
+        geomNPlaneCollider  	= dCollideCapsulePlane;
+        geomNDepthGetter		= dGeomCapsulePointDepth;
+        // max_collisionContact    = 3;
+        break;
+
+    case dCylinderClass:
+        geomRayNCollider		= dCollideRayCylinder;
+        geomNPlaneCollider	    = dCollideCylinderPlane;
+        geomNDepthGetter		= NULL;// TODO: dGeomCCylinderPointDepth
+        //max_collisionContact    = 3;
+        break;
+
+    case dConvexClass:
+        geomRayNCollider		= dCollideRayConvex;
+        geomNPlaneCollider  	= dCollideConvexPlane;
+        geomNDepthGetter		= NULL;// TODO: dGeomConvexPointDepth;
+        //max_collisionContact    = 3;
+        break;
+
+    default:
+        	// Shouldn't ever get here.
+        break;
+
+    }
+
+
+    const int numMaxContacts = dMIN (max_collisionContact, HEIGHTFIELDMAXCONTACTPERCELL);
+    
+    dxPlane myplane(0,0,0,0,0);
+    dxPlane* sliding_plane = &myplane;
+    dContactGeom *PlaneContact = m_p_data->m_contacts;    
+    flags = (flags & 0xffff0000) | HEIGHTFIELDMAXCONTACTPERCELL;
+    dReal triplane[4];
+    int i;
+
+    // check some trivial case.
+    // Vector Up plane
+    if (maxY - minY < dEpsilon)
+    {
+        // it's a single plane.
+        triplane[0] = 0;
+        triplane[1] = REAL(1.0);
+        triplane[2] = 0;
+        triplane[3] =  minY;
+        dGeomPlaneSetNoNormalize (sliding_plane, triplane);
+        // find collision and compute contact points
+        const int numPlaneContacts = geomNPlaneCollider (o2, sliding_plane, flags, PlaneContact, sizeof(dContactGeom));
+        for (i = 0; i < numPlaneContacts; i++)
+        {
+            pContact = CONTACT(contact, numTerrainContacts*skip);
+            const dVector3 &pCPos = PlaneContact[i].pos;
+            dVector3Copy (pCPos, pContact->pos);
+            dOPESIGN(pContact->normal, =, -, triplane);
+
+            pContact->depth = PlaneContact[i].depth;
+            numTerrainContacts++;
+            if (numTerrainContacts > numMaxContactsPossible)
+                break;
+        }
+        return numTerrainContacts;
+    }
+    // unique plane
+    {
+        // check for very simple plane heightfield
+        dReal minXHeightDelta = dInfinity, maxXHeightDelta = - dInfinity;
+        dReal minZHeightDelta = dInfinity, maxZHeightDelta = - dInfinity;
+
+
+        dReal lastXHeight = tempHeightBuffer[0][0].vertex[1];
+        for ( x_local = 1; x_local < numX; x_local++)
+        {
+            HeightFieldVertex *HeightFieldRow = tempHeightBuffer[x_local];
+
+            const dReal deltaX = HeightFieldRow[0].vertex[1] - lastXHeight;
+
+            maxXHeightDelta = dMAX (maxXHeightDelta,  deltaX);
+            minXHeightDelta = dMIN (minXHeightDelta,  deltaX);
+
+            dReal lastZHeight = HeightFieldRow[0].vertex[1];
+            for ( z_local = 1; z_local < numZ; z_local++)
+            {
+                const dReal deltaZ = (HeightFieldRow[z_local].vertex[1] - lastZHeight);
+
+                maxZHeightDelta = dMAX (maxZHeightDelta,  deltaZ);
+                minZHeightDelta = dMIN (minZHeightDelta,  deltaZ);
+
+            }
+        }
+
+        if (maxZHeightDelta - minZHeightDelta < dEpsilon && 
+            maxXHeightDelta - minXHeightDelta < dEpsilon )
+        {
+            // it's a single plane.
+            const dVector3 &A = tempHeightBuffer[0][0].vertex;
+            const dVector3 &B = tempHeightBuffer[1][0].vertex;
+            const dVector3 &C = tempHeightBuffer[0][1].vertex;
+
+            // define 2 edges and a point that will define collision plane
+            {
+                dVector3 Edge1, Edge2; 
+                dVector3Subtract(C, A, Edge1);
+                dVector3Subtract(B, A, Edge2);
+                dVector3Cross(Edge1, Edge2, triplane);
+            }
+
+            // Define Plane
+            // Normalize plane normal
+            const dReal dinvlength = dDIV(REAL(1.0),dVector3Length(triplane));
+            triplane[0] = dMUL(triplane[0],dinvlength);
+            triplane[1] = dMUL(triplane[1],dinvlength);
+            triplane[2] = dMUL(triplane[2],dinvlength);
+            // get distance to origin from plane 
+            triplane[3] = dVector3Dot(triplane, A);
+
+            dGeomPlaneSetNoNormalize (sliding_plane, triplane);
+            // find collision and compute contact points
+            const int numPlaneContacts = geomNPlaneCollider (o2, sliding_plane, flags, PlaneContact, sizeof(dContactGeom));
+            for (i = 0; i < numPlaneContacts; i++)
+            {
+                pContact = CONTACT(contact, numTerrainContacts*skip);
+                const dVector3 &pCPos = PlaneContact[i].pos;
+                dVector3Copy (pCPos, pContact->pos);
+                dOPESIGN(pContact->normal, =, -, triplane);
+
+                pContact->depth = PlaneContact[i].depth;
+                numTerrainContacts++;
+                if (numTerrainContacts > numMaxContactsPossible)
+                    break;
+            }
+            return numTerrainContacts;
+        }
+    }
+
+
+    const unsigned int numTriMax = (maxX - minX) * (maxZ - minZ) * 2;
+    if (tempTriangleBufferSize < numTriMax)
+    {
+        delete [] tempTriangleBuffer;
+        tempTriangleBufferSize = numTriMax;
+        tempTriangleBuffer = new HeightFieldTriangle[numTriMax];
+    }
+    
+    // Sorting triangle/plane  resulting from heightfield zone
+    // Perhaps that would be necessary in case of too much limited
+    // maximum contact point...
+    // or in complex mesh case (trimesh and convex)
+    // need some test or insights on this before enabling this.
+    const bool isContactNumPointsLimited = 
+        true;
+    // (numMaxContacts < 8)
+    //    || o2->type == dConvexClass
+    //    || o2->type == dTriMeshClass
+    //    || (numMaxContacts < (int)numTriMax)       
+        
+
+
+    // if small heightfield triangle related to O2 colliding
+    // or no Triangle colliding at all.
+    bool needFurtherPasses = (o2->type == dTriMeshClass);
+    //compute Ratio between Triangle size and O2 aabb size
+	// no FurtherPasses are needed in ray class
+    if (o2->type != dRayClass  && needFurtherPasses == false)
+    {
+        const dReal xratio = dMUL((o2->aabb[1] - o2->aabb[0]),m_p_data->m_fInvSampleWidth);
+        if (xratio > REAL(1.5))
+            needFurtherPasses = true;
+        else
+        {
+            const dReal zratio = dMUL((o2->aabb[5] - o2->aabb[4]),m_p_data->m_fInvSampleDepth);
+            if (zratio > REAL(1.5))
+                needFurtherPasses = true;
+        }
+
+    }
+
+    unsigned int numTri = 0;
+    HeightFieldVertex *A, *B, *C, *D;
+    /*    (y is up)
+         A--------B-...x
+         |       /|
+         |      / |
+         |     /  |
+         |    /   |
+         |   /    |
+         |  /     |
+         | /      |
+         |/       |
+         C--------D   
+         .
+         .
+         .
+         z
+    */  
+    // keep only triangle that does intersect geom
+    for ( x = minX, x_local = 0; x < maxX; x++, x_local++)
+    {
+        HeightFieldVertex *HeightFieldRow      = tempHeightBuffer[x_local];
+        HeightFieldVertex *HeightFieldNextRow  = tempHeightBuffer[x_local + 1];
+
+        // First A
+        C = &HeightFieldRow    [0];
+        // First B
+        D = &HeightFieldNextRow[0];
+        for ( z = minZ, z_local = 0; z < maxZ; z++, z_local++)
+        {
+            A = C;
+            B = D;
+
+            C = &HeightFieldRow    [z_local + 1];
+            D = &HeightFieldNextRow[z_local + 1];
+
+            const dReal AHeight = A->vertex[1];
+            const dReal BHeight = B->vertex[1];
+            const dReal CHeight = C->vertex[1];
+            const dReal DHeight = D->vertex[1];
+
+            const bool isACollide = 0 < AHeight - minO2Height;
+            const bool isBCollide = 0 < BHeight - minO2Height;
+            const bool isCCollide = 0 < CHeight - minO2Height;
+            const bool isDCollide = 0 < DHeight - minO2Height;
+
+            A->state = !(isACollide);
+            B->state = !(isBCollide);
+            C->state = !(isCCollide);
+            D->state = !(isCCollide);
+
+            if (isACollide || isBCollide || isCCollide)
+            {
+                HeightFieldTriangle * const CurrTriUp = &tempTriangleBuffer[numTri++];
+
+                CurrTriUp->state = false;
+
+                // changing point order here implies to change it in isOnHeightField
+                CurrTriUp->vertices[0] = A;
+                CurrTriUp->vertices[1] = B;
+                CurrTriUp->vertices[2] = C;
+
+                if (isContactNumPointsLimited)
+                    CurrTriUp->setMinMax();
+                CurrTriUp->isUp = true;
+            }
+
+            if (isBCollide || isCCollide || isDCollide)
+            {
+                HeightFieldTriangle * const CurrTriDown = &tempTriangleBuffer[numTri++];
+
+                CurrTriDown->state = false;
+                // changing point order here implies to change it in isOnHeightField
+
+                CurrTriDown->vertices[0] = D;
+                CurrTriDown->vertices[1] = B;
+                CurrTriDown->vertices[2] = C;
+
+
+                if (isContactNumPointsLimited)
+                    CurrTriDown->setMinMax();
+                CurrTriDown->isUp = false;
+            }
+
+
+            if (needFurtherPasses &&
+                (isBCollide || isCCollide)
+                &&
+                (AHeight - CHeight > 0 &&
+                 AHeight - BHeight > 0 &&
+                 DHeight - CHeight > 0 &&
+                 DHeight - BHeight > 0))
+            {
+                // That means Edge BC is concave, therefore
+                // BC Edge and B and C vertices cannot collide
+
+                B->state = true;
+                C->state = true;
+            }
+            // should find a way to check other edges (AB, BD, CD) too for concavity
+        }
+    }
+
+    // at least on triangle should intersect geom
+
+    // pass1: VS triangle as Planes
+    // Group Triangle by same plane definition
+    // as Terrain often has many triangles using same plane definition
+    // then collide against that list of triangles.
+    {
+
+        dVector3 Edge1, Edge2;
+        //compute all triangles normals.
+        for (unsigned int k = 0; k < numTri; k++)
+        {
+            HeightFieldTriangle * const itTriangle = &tempTriangleBuffer[k];
+
+            // define 2 edges and a point that will define collision plane
+            dVector3Subtract(itTriangle->vertices[2]->vertex, itTriangle->vertices[0]->vertex, Edge1);
+            dVector3Subtract(itTriangle->vertices[1]->vertex, itTriangle->vertices[0]->vertex, Edge2);
+
+            // find a perpendicular vector to the triangle
+            if  (itTriangle->isUp)
+                dVector3Cross(Edge1, Edge2, triplane);
+            else
+                dVector3Cross(Edge2, Edge1, triplane);
+
+            // Define Plane
+            // Normalize plane normal
+            const dReal dinvlength = dDIV(1,dVector3Length(triplane));
+            triplane[0] = dMUL(triplane[0],dinvlength);
+            triplane[1] = dMUL(triplane[1],dinvlength);
+            triplane[2] = dMUL(triplane[2],dinvlength);
+            // get distance to origin from plane 
+            triplane[3] = dVector3Dot(triplane, itTriangle->vertices[0]->vertex);
+
+            // saves normal for collision check (planes, triangles, vertices and edges.)
+            dVector3Copy(triplane, itTriangle->planeDef);
+            // saves distance for collision check (planes, triangles, vertices and edges.)
+            itTriangle->planeDef[3] = triplane[3];
+        }
+
+        // group by Triangles by Planes sharing shame plane definition
+        if (tempPlaneBufferSize  < numTri)
+        {
+            delete [] tempPlaneBuffer;
+            tempPlaneBufferSize = numTri;
+            tempPlaneBuffer = new HeightFieldPlane *[numTri];
+
+            for (unsigned int k = 0; k < tempPlaneBufferSize; k++)
+            {
+                tempPlaneBuffer[k] = new HeightFieldPlane();
+            }
+        }
+        unsigned int numPlanes = 0;
+        for (unsigned int k = 0; k < numTri; k++)
+        {
+            HeightFieldTriangle * const tri_base = &tempTriangleBuffer[k];
+
+            if (tri_base->state == true)
+                continue;// already tested or added to plane list.
+
+            HeightFieldPlane * const currPlane = tempPlaneBuffer[numPlanes];
+            currPlane->resetTriangleListSize(numTri - k);
+            currPlane->addTriangle(tri_base);
+            // saves normal for collision check (planes, triangles, vertices and edges.)
+            dVector3Copy(tri_base->planeDef, currPlane->planeDef);
+            // saves distance for collision check (planes, triangles, vertices and edges.)
+            currPlane->planeDef[3]= tri_base->planeDef[3];
+
+            const dReal normx = tri_base->planeDef[0];
+            const dReal normy = tri_base->planeDef[1];
+            const dReal normz = tri_base->planeDef[2];
+            const dReal dist = tri_base->planeDef[3];
+
+            for (unsigned int m = k + 1; m < numTri; m++)
+            {
+
+                HeightFieldTriangle * const tri_test = &tempTriangleBuffer[m];
+                if (tri_test->state == true)
+                    continue;// already tested or added to plane list.
+
+                // normals and distance are the same.
+                if (
+                    dFabs(normy - tri_test->planeDef[1]) < dEpsilon &&  
+                    dFabs(dist  - tri_test->planeDef[3]) < dEpsilon &&
+                    dFabs(normx - tri_test->planeDef[0]) < dEpsilon && 
+                    dFabs(normz - tri_test->planeDef[2]) < dEpsilon
+                    )
+                {
+                    currPlane->addTriangle (tri_test);
+                    tri_test->state = true;
+                }
+            }
+
+            tri_base->state = true;
+            if (isContactNumPointsLimited)
+                currPlane->setMinMax();
+
+            numPlanes++;
+        }
+
+        // sort planes
+        if (isContactNumPointsLimited)
+            sortPlanes(numPlanes);
+
+        for (unsigned int k = 0; k < numPlanes; k++)
+        {
+            HeightFieldPlane * const itPlane = tempPlaneBuffer[k];
+
+            //set Geom
+            dGeomPlaneSetNoNormalize (sliding_plane,  itPlane->planeDef);
+            //dGeomPlaneSetParams (sliding_plane, triangle_Plane[0], triangle_Plane[1], triangle_Plane[2], triangle_Plane[3]);
+            // find collision and compute contact points
+            bool didCollide = false;
+            const int numPlaneContacts = geomNPlaneCollider (o2, sliding_plane, flags, PlaneContact, sizeof(dContactGeom));
+            const size_t planeTriListSize = itPlane->trianglelistCurrentSize;
+            for (i = 0; i < numPlaneContacts; i++)
+            {
+                // Check if contact point found in plane is inside Triangle.
+                const dVector3 &pCPos = PlaneContact[i].pos;
+                bool isOnOneOfTrianglePlane = false;
+                for (size_t b = 0; planeTriListSize > b; b++)
+                {  
+                    if (m_p_data->IsOnHeightfield2 (itPlane->trianglelist[b]->vertices[0]->vertex, 
+                                                    pCPos, 
+                                                    itPlane->trianglelist[b]->isUp))
+                    {
+                        isOnOneOfTrianglePlane = true;
+                        break;
+                    }
+                }
+                if ( isOnOneOfTrianglePlane)
+                {
+                    pContact = CONTACT(contact, numTerrainContacts*skip);
+                    dVector3Copy(pCPos, pContact->pos);
+                    dOPESIGN(pContact->normal, =, -, itPlane->planeDef);
+                    pContact->depth = PlaneContact[i].depth;
+                    didCollide = true;
+                    numTerrainContacts++;
+                    if ( numTerrainContacts == numMaxContacts ) 
+                        return numTerrainContacts;
+                }
+            }
+            if (didCollide)
+            {
+                for (size_t b = 0; planeTriListSize > b; b++)
+                {                      
+                    // flag Triangles Vertices as collided 
+                    // to prevent any collision test of those
+                    for (i = 0; i < 3; i++)
+                        itPlane->trianglelist[b]->vertices[i]->state = true;
+                }
+            }
+            else 
+            {
+                // flag triangle as not collided so that Vertices or Edge
+                // of that triangles will be checked.
+                for (size_t b = 0; planeTriListSize > b; b++)
+                { 
+                    itPlane->trianglelist[b]->state = false;
+                }
+            }
+        }
+    }
+    
+
+   
+    // pass2: VS triangle vertices
+    if (needFurtherPasses)
+    {
+        dxRay tempRay(0, 1); 
+        dReal depth;
+        bool vertexCollided;
+        //
+        // Find Contact Penetration Depth of each vertices
+        //
+        for (unsigned int k = 0; k < numTri; k++)
+        {
+            const HeightFieldTriangle * const itTriangle = &tempTriangleBuffer[k];
+            if (itTriangle->state == true)
+                continue;// plane triangle did already collide.
+
+            for (size_t i = 0; i < 3; i++)
+            {
+                HeightFieldVertex *vertex = itTriangle->vertices[i];
+                if (vertex->state == true)
+                    continue;// vertice did already collide.
+
+                vertexCollided = false;
+                const dVector3 &triVertex = vertex->vertex;
+                if ( geomNDepthGetter )
+                {
+                    depth = geomNDepthGetter( o2,
+                        triVertex[0], triVertex[1], triVertex[2] );
+                    if (depth + dEpsilon < 0)
+                        vertexCollided = true;
+                }
+                else
+                {
+                    // We don't have a GetDepth function, so do a ray cast instead.
+                    // NOTE: This isn't ideal, and a GetDepth function should be
+                    // written for all geom classes.
+                    tempRay.length = (minO2Height - triVertex[1]) * REAL(1000.f);
+
+                    //dGeomRaySet( &tempRay, pContact->pos[0], pContact->pos[1], pContact->pos[2],
+                    //    - itTriangle->Normal[0], - itTriangle->Normal[1], - itTriangle->Normal[2] );
+                    dGeomRaySetNoNormalize(tempRay, triVertex, itTriangle->planeDef);
+
+                    if ( geomRayNCollider( &tempRay, o2, flags, PlaneContact, sizeof( dContactGeom ) ) )
+                    {
+                        depth = PlaneContact[0].depth;
+                        vertexCollided = true;
+                    }
+                }
+                if (vertexCollided)
+                {
+                    pContact = CONTACT(contact, numTerrainContacts*skip);
+                    //create contact using vertices
+                    dVector3Copy (triVertex, pContact->pos);
+                    //create contact using Plane Normal
+                    dOPESIGN(pContact->normal, =, -, itTriangle->planeDef);
+
+                    pContact->depth = depth;
+
+                    numTerrainContacts++;
+                    if ( numTerrainContacts == numMaxContacts ) 
+                        return numTerrainContacts;
+
+                    vertex->state = true;
+                }
+            }
+        }
+    }
+
+    return numTerrainContacts;
+}
+
+int dCollideHeightfield( dxGeom *o1, dxGeom *o2, int flags, dContactGeom* contact, int skip )
+{
+
+    int i;
+
+    if ((flags & 0xffff) == 0)
+        flags = (flags & 0xffff0000) | 1;
+
+    int numMaxTerrainContacts = (flags & 0xffff);
+    dxHeightfield *terrain = (dxHeightfield*) o1;
+
+    dVector3 posbak;
+    dMatrix3 Rbak;
+    dReal aabbbak[6];
+    int gflagsbak;
+    dVector3 pos0,pos1;
+    dMatrix3 R1;
+
+    int numTerrainContacts = 0;
+
+    //@@ Should find a way to set reComputeAABB to false in default case
+    // aka DHEIGHTFIELD_CORNER_ORIGIN not defined and terrain not PLACEABLE
+    // so that we can free some memory and speed up things a bit
+    // while saving some precision loss 
+
+    const bool reComputeAABB = true;
+
+    //
+    // Transform O2 into Heightfield Space
+    //
+    if (reComputeAABB)
+    {
+        // Backup original o2 position, rotation and AABB.
+        dVector3Copy( o2->final_posr->pos, posbak );
+        dMatrix3Copy( o2->final_posr->R, Rbak );
+        memcpy( aabbbak, o2->aabb, sizeof( dReal ) * 6 );
+        gflagsbak = o2->gflags;
+    }
+
+    if ( terrain->gflags & GEOM_PLACEABLE )
+    {
+        // Transform o2 into heightfield space.
+        dOP( pos0, -, o2->final_posr->pos, terrain->final_posr->pos );
+        dMULTIPLY1_331( pos1, terrain->final_posr->R, pos0 );
+        dMULTIPLY1_333( R1, terrain->final_posr->R, o2->final_posr->R );
+
+        // Update o2 with transformed position and rotation.
+        dVector3Copy( pos1, o2->final_posr->pos );
+        dMatrix3Copy( R1, o2->final_posr->R );
+    }
+
+
+    o2->final_posr->pos[ 0 ] += terrain->m_p_data->m_fHalfWidth;
+    o2->final_posr->pos[ 2 ] += terrain->m_p_data->m_fHalfDepth;
+
+    // Rebuild AABB for O2
+    if (reComputeAABB)
+        o2->computeAABB();
+
+    //
+    // Collide
+    //
+
+    //check if inside boundaries
+    // using O2 aabb
+    //  aabb[6] is (minx, maxx, miny, maxy, minz, maxz) 
+    const bool notWrapped = terrain->m_p_data->m_bWrapMode == 0;
+
+    int nMinX;
+    int nMaxX;
+    int nMinZ;
+    int nMaxZ;
+
+    if ( notWrapped )
+    {
+        if (    o2->aabb[0] > terrain->m_p_data->m_fWidth //MinX
+            &&  o2->aabb[4] > terrain->m_p_data->m_fDepth)//MinZ
+            goto dCollideHeightfieldExit;
+
+        if (    o2->aabb[1] < 0 //MaxX
+            &&  o2->aabb[5] < 0) //MaxZ
+            goto dCollideHeightfieldExit;
+
+    }
+
+    nMinX = dMUL(o2->aabb[0],terrain->m_p_data->m_fInvSampleWidth)>>QFACTOR;
+    nMaxX = dMUL(o2->aabb[1],terrain->m_p_data->m_fInvSampleWidth)>>QFACTOR + 1;
+    nMinZ = dMUL(o2->aabb[4],terrain->m_p_data->m_fInvSampleDepth)>>QFACTOR;
+    nMaxZ = dMUL(o2->aabb[5],terrain->m_p_data->m_fInvSampleDepth)>>QFACTOR + 1;
+
+    if ( notWrapped )
+    {
+        nMinX = dMAX( nMinX, 0 );
+        nMaxX = dMIN( nMaxX, terrain->m_p_data->m_nWidthSamples - 1 );
+        nMinZ = dMAX( nMinZ, 0 );
+        nMaxZ = dMIN( nMaxZ, terrain->m_p_data->m_nDepthSamples - 1 );
+	
+    }
+
+
+
+    numTerrainContacts  = terrain->dCollideHeightfieldZone(
+        nMinX,nMaxX,nMinZ,nMaxZ,o2,numMaxTerrainContacts - numTerrainContacts,
+        flags,CONTACT(contact,numTerrainContacts*skip),skip	);
+
+
+        dContactGeom *pContact;
+        for ( i = 0; i < numTerrainContacts; ++i )
+        {
+            pContact = CONTACT(contact,i*skip);
+            pContact->g1 = o1;
+            pContact->g2 = o2;
+        }
+
+
+        //------------------------------------------------------------------------------
+
+dCollideHeightfieldExit:
+
+        if (reComputeAABB)
+        {
+            // Restore o2 position, rotation and AABB
+            dVector3Copy( posbak, o2->final_posr->pos );
+            dMatrix3Copy( Rbak, o2->final_posr->R );
+            memcpy( o2->aabb, aabbbak, sizeof(dReal)*6 );
+            o2->gflags = gflagsbak;
+
+            //
+            // Transform Contacts to World Space
+            //
+            if ( terrain->gflags & GEOM_PLACEABLE )
+            {
+                for ( i = 0; i < numTerrainContacts; ++i )
+                {
+                    pContact = CONTACT(contact,i*skip);
+                    dOPE( pos0, =, pContact->pos );
+
+
+                    pos0[ 0 ] -= terrain->m_p_data->m_fHalfWidth;
+                    pos0[ 2 ] -= terrain->m_p_data->m_fHalfDepth;
+
+
+                    dMULTIPLY0_331( pContact->pos, terrain->final_posr->R, pos0 );
+
+                    dOP( pContact->pos, +, pContact->pos, terrain->final_posr->pos );
+                    dOPE( pos0, =, pContact->normal );
+
+                    dMULTIPLY0_331( pContact->normal, terrain->final_posr->R, pos0 );
+                }
+            }
+
+            else
+            {
+                for ( i = 0; i < numTerrainContacts; ++i )
+                {
+                    pContact = CONTACT(contact,i*skip);
+                    pContact->pos[ 0 ] -= terrain->m_p_data->m_fHalfWidth;
+                    pContact->pos[ 2 ] -= terrain->m_p_data->m_fHalfDepth;
+                }
+            }
+
+        }
+        // Return contact count.
+        return numTerrainContacts;
+}
+
+