I am making 3 long floating shelves, (7.5 feet), the top, bottom, and middle section all are 45 miter, and with table saw, not matter how careful I tried, the end result of the long bevel board look awful, the left side and the right side of the board has almost 1/16 difference in height.

Is this something that is not supposed to be done on table saw? Or there is some special trick I did not know?

Or tracksaw is the only solution here? Thanks