rayshooter_sample.cpp

int ShootRayOnCollection(ON_3dPoint point, ON_3dVector direction,
																					 const ON_SimpleArray<const ON_Geometry*>* pConstGeometryArray,
																					 ON_SimpleArray<ON_3dPoint>* pPoints, int maxReflections)
{
	int rc = 0;

	// Currently only supports surfaces and breps with untrimmed faces.
	// Add support for meshes and trimmed breps

	int count = pConstGeometryArray?pConstGeometryArray->Count():0;
	if( count<1 )
		return 0;
	ON_SimpleArray<const ON_SurfaceTreeNode*> snode_list(count);
	for ( int i=0; i<count; i++ )
	{
		const ON_Geometry* pGeometry = (*pConstGeometryArray)[i];
		const ON_Surface* surface = ON_Surface::Cast(pGeometry);
		if ( surface )
		{
			const ON_SurfaceTree* stree = surface->SurfaceTree();
			if ( stree )
				snode_list.Append(stree);
			continue;
		}
		const ON_Brep* brep = ON_Brep::Cast(pGeometry);
		if( brep )
		{
			for( int fi=0; fi<brep->m_F.Count(); fi++ )
			{
				const ON_SurfaceTree* stree = brep->m_F[fi].SurfaceTree();
				if( stree )
				snode_list.Append(stree);
			}
			continue;
		}
	}
	if( snode_list.Count()<1 )
		return 0;

	if( pPoints && maxReflections>0 && point.IsValid() && direction.Unitize() )
	{
		ON_RayShooter shooter;
		ON_X_EVENT hit;
		ON_3dPoint Q = point;
		ON_3dVector R = direction;
		for( int i=0; i<maxReflections; i++ )
		{
			memset(&hit,0,sizeof(hit));
			ON_3dVector T = R;
			if( !T.Unitize() )
				break;
			if( !shooter.Shoot(Q,T,snode_list,hit) )
				break;
			Q = hit.m_A[0];
			pPoints->Append(Q);
			if( !hit.m_snodeB[0] )
				break;

			ON_3dVector N = hit.m_B[1]; // surface normal
			double d = -2.0*(N.x*T.x + N.y*T.y + N.z*T.z);
			R.x = T.x + d*N.x;
			R.y = T.y + d*N.y;
			R.z = T.z + d*N.z;

			d = hit.m_A[0].DistanceTo( hit.m_B[0] );
			shooter.m_min_travel_distance = d;
			if( shooter.m_min_travel_distance < 1.0e-8 )
				shooter.m_min_travel_distance = 1.0e-8;
		}
		rc = pPoints->Count();
	}
	return rc;
}

CRhinoCommand::result CCommandRayShooter::RunCommand(const CRhinoCommandContext& context)
{

	ON_3dPoint p(10.0, 10.0, 10.0);
	ON_3dVector d(1, -1, -1);

	const CRhinoObject* object = 0;
	CRhinoObjectIterator it(CRhinoObjectIterator::normal_objects, CRhinoObjectIterator::active_objects);
	it.SetObjectFilter(ON::object_type::brep_object | ON::object_type::surface_object);
	ON_SimpleArray<const ON_Geometry*> obs;
	for (object = it.First(); 0 != object; object = it.Next())
	{
		const ON_Geometry* geom = object->Geometry();
		if (geom == nullptr) continue;
		obs.Append(geom);
	}
	ON_SimpleArray<ON_3dPoint> pts;
	int totalhits = ShootRayOnCollection(p, d, &obs, &pts, 1);


	return CRhinoCommand::success;
}