So after some research i chose to do planar reflection for flat water surface, and maybe for some windows etc.

However over net there are some things not covered up entirely like: reflection matrix, and how would i draw refraction texture.

so first of all they claim to use reflection matrix and multiple point by it. But wait a second (http://web.cse.ohio-state.edu/~shen.94/781/Site/Slides_files/reflection.pdf​ page 6)

Not to mention what is actually 4th column (2(P.v)V.x) ???? (P.V) means dot of itself or wat?

How would i even try to pass it to gl_Position in vertex shader

is it (relfectionview)projection ? or (model*reflection)*projection?

and then i multiple this by vertex coord? or is it (mvp*reflection)*vertex?

Maybe theres a better way of doing this without involving cubemaps.

Maybe drawing to reflection tex through different view but then how would i know how to flip it so it corresponds to normal and distance of reflected plane.

ALSO

How would i render refraction texture below waterline.

Its been years since i touched that stuff ughhhh…