We are developing a next-generation 3D display which offers natural 3D images by projecting a number of directional images. We have already demonstrated a prototype 3D display which generates 64 directional images simultaneously by using 64 LCD panels. In this study we developed a 3D interactive processor which can process 64 directional images simultaneously by using a PC cluster. The PC cluster consisted of 64 small PC's. The image synchronization mechanism was implemented to update 64 directional images at the same time. We made the commands to control the system and the API used for programming. The processor can display moving 3D images with 30 fps. The 3D images can be interactively updated according to the 3D mouse. We also developed the interpreter programs for the DXF and VRML data so that the 3D interactive processor can deal widely-used 3D data in the DXF and VRML formats.