The distance between the objects is supposed to be certain percentages apart. These percentages need to be precise for they are extremely important to make the diorama look accurate to the eye. It takes a lot of math to make out scales that are proportional from the actual size of the objects to the appeared size. Backgrounds are very important because the set up the visual that adds to the diorama. The next item need in a forced perspective model is a 2-D object. This could include buildings, trees, and anything that relates to the background. Next, should be a partial object that adds depth to the diorama. The final step to creating forced perspective is to add objects that are full-scaled like miniature trees or cars. These measurements are for scences. Another type of forced perspective could be with actual actors. In certain movies where one character is supposed to be smaller than the other, one actor is placed further away from the camera than the other character, which gives the idea that one is a giant or one is a dwarf.