Intersecting Meshes
Windows only

Demonstrates how to intersect two meshes.

/*
Description:
Intersects two meshes.
Parameters:
meshA     - [in]  The first mesh.
meshB     - [in]  The second mesh.
OutCurves - [out] The resulting polyline curves.
NOTE: THE CALLER IS RESPONSIBLE FOR
DESTROYING THESE CURVES.
tolerance - [in]  The intersection tolerance.
Returns:
True if successful, false otherwise.
*/
static bool MeshMeshIntersection(
const ON_Mesh* meshA,
const ON_Mesh* meshB,
ON_SimpleArray<ON_Curve*>& OutCurves,
double tolerance = ON_ZERO_TOLERANCE
)
{
if( 0 == meshA | 0 == meshB )
return false;

ON_ClassArray<ON_MMX_Polyline> transverse;
ON_ClassArray<ON_MMX_Polyline> overlap;
bool rc = ON_MeshMeshIntersect( meshA, meshB, transverse, overlap, tolerance, tolerance );
if( !rc )
return rc;

ON_ClassArray<ON_MMX_Polyline>& arr = transverse;
int i, j, k;
for( i = 0; i < 2; i++ )
{
if( i == 1 )
arr = overlap;

int ct = arr.Count();
for( j = 0; j < ct; j++ )
{
ON_MMX_Polyline& mmxpline = arr[j];
if( 0 == mmxpline.Count() )
continue;

ON_Polyline polyline;
for( k = 0; k < mmxpline.Count(); k++ )
{
double x = mmxpline[k].m_A.m_P.x;
double y = mmxpline[k].m_A.m_P.y;
double z = mmxpline[k].m_A.m_P.z;
polyline.Append( ON_3dPoint(x,y,z) );
}

if( false == polyline.IsValid() )
continue;

ON_PolylineCurve* polyline_crv = new ON_PolylineCurve( polyline );
if( 0 == polyline_crv )
continue;

OutCurves.Append( polyline_crv );
}
}

return ( OutCurves.Count() ) ? true : false;
}

CRhinoCommand::result CCommandTest::RunCommand( const CRhinoCommandContext& context )
{
CRhinoGetObject go;
go.SetCommandPrompt( L"Select meshes to intersect" );
go.SetGeometryFilter( CRhinoGetObject::mesh_object );
go.GetObjects( 2, 2 );
if( go.CommandResult() != success )
return go.CommandResult();

const ON_Mesh* meshA = go.Object(0).Mesh();
const ON_Mesh* meshB = go.Object(1).Mesh();
if( 0 == meshA | 0 == meshA )
return failure;

ON_SimpleArray<ON_Curve*> OutCurves;
bool rc = MeshMeshIntersection( meshA, meshB, OutCurves );
if( rc )
{
int i;
for( i = 0; i < OutCurves.Count(); i++ )
{
CRhinoCurveObject* curve_obj = new CRhinoCurveObject();
curve_obj->SetCurve( OutCurves[i] );