Lightly coat two 15x10 inch baking pans with cooking spray.
Divide eggplant, zucchini, mushrooms, and onion evenly between prepared pans.
Drizzle oil over vegetables.
Sprinkle with salt and pepper.
Toss vegetables to coat; spread into an even layer.
Roast, uncovered, on 2 separate oven racks at 450° for 30 minutes or until vegetables are tender, stirring once during roasting (move baking pan on top oven rack to bottom rack and pan on bottom rack to top rack halfway through roasting).
Meanwhile, cook rigatoni by following the package directions; drain and return to saucepan.
Lower oven temperature to 400°.
Add vegetables, marinara sauce, and parmesan cheese to the pasta; toss to combine.
Transfer to an ungreased 2 quart casserole dish.
Sprinkle with mozzarella.
Bake, uncovered, for 20-25 minutes or until bubbly and cheese browns.