At least one of material IDs is changed to a different material ID for each of voxels corresponding to a voxel update range, and a display mesh is updated in association with updated voxel data. In addition, generating an in-game behavior based on collision determination between a determination mesh in which a material is determined based on at least a plurality of materials ID included in voxel data, and a determination shape corresponding to a determination target, and a virtual space including a display mesh is rendered based on vertex coordinates of the display mesh and a texture corresponding to a material for the display mesh.