main/src/georegression/geometry/GeometryMath_F64.java
public static DMatrixRMaj crossMatrix( GeoTuple3D_F64 v, DMatrixRMaj ret ) {
		if( ret == null ) {
			ret = new DMatrixRMaj( 3, 3 );
		} else {
			ret.zero();
		}

		double x = v.getX();
		double y = v.getY();
		double z = v.getZ();

		ret.set( 0, 1, -z );
		ret.set( 0, 2, y );
		ret.set( 1, 0, z );
		ret.set( 1, 2, -x );
		ret.set( 2, 0, -y );
		ret.set( 2, 1, x );

		return ret;
	}
public static DMatrixRMaj crossMatrix( GeoTuple3D_F64 v, DMatrixRMaj ret ) {
		if( ret == null ) {
			ret = new DMatrixRMaj( 3, 3 );
		} else {
			ret.zero();
		}

		double x = v.getX();
		double y = v.getY();
		double z = v.getZ();

		ret.set( 0, 1, -z );
		ret.set( 0, 2, y );
		ret.set( 1, 0, z );
		ret.set( 1, 2, -x );
		ret.set( 2, 0, -y );
		ret.set( 2, 1, x );

		return ret;
	}
Creates a skew symmetric cross product matrix from the provided tuple.

@param v Tuple. Not modified.
@param ret If not null the results are stored here, otherwise a new matrix is created.
@return Skew symmetric cross product matrix.