A Sketch-based System for Cloud Volume Retrieval from Simulated Dataset for Realistic Image Synthesis

For creating synthetic images of outdoor scenes, clouds play an important role to enhance the realism of the scene. Therefore, many methods have been proposed for visual simulation of clouds. However, in order to generate realistic clouds, the user has to adjust many parameters involved in the methods. Although choosing appropriate parameters is not a difficult task for experienced users, it becomes a serious problem for novice users who have no sufficient prior knowledge on nether the parameters nor the methods. In order to address this problem, we propose a sketch-based retrieval system for cloud volumes by using a precomputed database. The database of cloud volumes is generated in advance by numerical analysis of atmospheric fluid dynamics. Next, the user sketches the desired shape of clouds at the desired position on the screen and then our system searches for the optimal cloud volume from the database. Our system allows the novice users to intuitively design the desired and realistic cloud scene.