Most volume renderings in medical application today employ one-dimensional transfer functions, which assign color and opacity to samples solely on their intensity value. The method is not effective when it is used on volumes that contain different materials sharing some common value range. The current method using multi-dimensional transfer function based on the introduction of gradient magnitude can achieve a better classified rendering result, but the implementation of the method depends on a relatively complex user-interface. An alternative method will be introduced in this article, which first takes advantage of multiple segmentation results to map the value of different materials to separate intervals, and then render the resulting volume with a typical rendering module using one-dimensional transfer functions. A clear contrast between different tissues can be achieved by setting the transfer functions by pieces according to the gray intervals standing for different materials. The implementation and the usage of the method are both quite simple.