_calculatePointsExample.py

def _calculatePointOnPlane(self, x, y):
    from opencmiss.utils.maths.algorithms import calculateLinePlaneIntersection

    far_plane_point = self.unproject(x, -y, -1.0)
    near_plane_point = self.unproject(x, -y, 1.0)
    plane_point, plane_offset, plane_normal = self._model.getPlaneDescription()
    point_on_plane = calculateLinePlaneIntersection(near_plane_point, far_plane_point, plane_point, plane_normal)
    if len(self.grid) < 4:
        self.grid.append(point_on_plane)
    else:
        self.grid = []
        self.grid.append(point_on_plane)
    return point_on_plane