1. A non-transitory computer-readable medium storing a three-dimensional simulation program that is executed by a three-dimensional simulation apparatus including a memory that stores form information of a sheet flexible object model formed of first polygons and another object model, the three-dimensional simulation program causing the three-dimensional simulation apparatus to: determine whether the sheet flexible object model formed of the first polygons in three-dimensional simulation space interferes with the other object model on the basis of the form information stored in the memory; form second polygons by dividing the sheet flexible object model in a longitudinal direction when determining that the sheet flexible object model interferes with the other object model; and determine a shape of the sheet flexible object model using the formed second polygons in consideration of a shape of the other object model.