int findClosestVertexToMouse(MeshDeformer mesh, Camera cam)
        {
            Ray     cameraRay = mainCamera.ScreenPointToRay(curMousePosition);
            Vector3 start     = filter.transform.InverseTransformPoint(cameraRay.origin);
            Vector3 end       = filter.transform.InverseTransformPoint(cameraRay.origin + (cameraRay.direction * mainCamera.farClipPlane));

            int closestVertex = -1; float closestSqrDistance = 100000.0f;

            for (int i = 0; i < calibrationMesh.distortedMeshVertices.Length; i++)
            {
                float currentSqrDistance = SqrDistanceToSegment(calibrationMesh.distortedMeshVertices[i], start, end);
                if (currentSqrDistance < closestSqrDistance)
                {
                    closestVertex      = i;
                    closestSqrDistance = currentSqrDistance;
                }
            }
            return(closestVertex);
        }