A new utility of computer graphics (CG)-based simulation in the class is discussed in connection with the Active Learning through the activity in the physics class of National Institute of Technology, Tsuruoka college. It is proposed to utilize the simulation to connect the learner’s schema in daily life with the system learned in physics class. Especially, it is aimed to effectively introduce the concept of idealization in the fundamental physics for learners. This topic is closely related with how to motivate the learner toward the active and independent learning beyond the memorization-based learning like pattern matching.