VOLUME RENDERING METHOD WHICH INCREASES APPARENT OPACITY OF SEMI- TRANSPARENT OBJECTS IN REGIONS HAVING HIGHER SPECULAR REFLECTIVITY

Portions showing greater specular reflection of an object to be displayed are displayed with pixels whose opacity, .alpha..sub.1, is emphasized according to the specular reflected component of a shading model, in which case the specular reflected component thus calculated for shading is also utilized for arithmetic operation of emphasized opacity, .alpha..sub.1, and high-speed processing is sought through tabulating various variables such as .alpha..sub.s (an additional opacity introduced for emphasis by a specular reflected component), .alpha..sub.n (a primary opacity), and G (a gradient vector).