I know it is basic stuff, but If is there any chance, are there any visual examples for applying perspective projection (like the one Jim draw on a blackboard in today's lecture)
adrian_TA
@byungjul This is a pretty good overview with diagrams.
byungjul
Thanks!
yuanzhec
Why can we throw out the third component after homogeneous division?
qhy
@yuanzhec I think it's because the third component is only for calculating the coordinates of the projected points. Therefore, it's thrown away once it finished its task
cche
I might miss it in the lecture. How can we interpret the third dimension in Px? It can be any number? Is there a geometry meaning of it?
jmccann
It turns out that this particular transformation matrix always computes '1' for this component, which makes it pretty useless. A "real" projection matrix has a more interesting third row, which will end up storing (a scaled version of) 1/z in the third component, where it will be very useful for z-buffer-based depth sorting.
I know it is basic stuff, but If is there any chance, are there any visual examples for applying perspective projection (like the one Jim draw on a blackboard in today's lecture)
@byungjul This is a pretty good overview with diagrams.
Thanks!
Why can we throw out the third component after homogeneous division?
@yuanzhec I think it's because the third component is only for calculating the coordinates of the projected points. Therefore, it's thrown away once it finished its task
I might miss it in the lecture. How can we interpret the third dimension in Px? It can be any number? Is there a geometry meaning of it?
It turns out that this particular transformation matrix always computes '1' for this component, which makes it pretty useless. A "real" projection matrix has a more interesting third row, which will end up storing (a scaled version of) 1/z in the third component, where it will be very useful for z-buffer-based depth sorting.