Bring a large pot of salted water to a boil. Cook the rigatoni according to package directions. Drain and reserve.
Heat a grill pan or outdoor grill over medium high heat. Brush the vegetable oil on both sides of the eggplant and zucchini and all over the corn. Sprinkle with salt and pepper.
Grill the eggplant and zucchini on both sides until vegetables are softened and have nice grill marks (about 2 minutes per side). Grill corn turning until all sides have grill marks.
Roughly chop the eggplant and zucchini. Remove corn kernels from the cob. Place in a large bowl.
Add the tomato, feta, rigatoni, vinaigrette and parsley. Toss to combine. Taste and adjust seasoning.