It's weird to think that the center of a line would be projected off center in a perspective transformation. However, thinking about the mapping between pixels in screen space and texture space makes it a little more intuitive. The value of dl/dy (length along line over length along screen) goes up and up as you move from P0 to P1.
It's weird to think that the center of a line would be projected off center in a perspective transformation. However, thinking about the mapping between pixels in screen space and texture space makes it a little more intuitive. The value of dl/dy (length along line over length along screen) goes up and up as you move from P0 to P1.