View Full Version : Paraboloid

Rick T
10-28-2011, 12:05 PM
I understand the mathematics of this shape and I want to use OpenGL to display it. How does one display something other than a sphere or cylinder ? I've been studying the "OpenGL SuperBible" , but am not sure how to define the shape for use in OpenGL. Once I know this I think I can figure out how to display it.
Any help geatly appreciated.


10-28-2011, 02:24 PM
you gotta point your vertexes to the positions you want in a opengl window you created it is like this the numbers represent the axis so the first is x axis (0.0) the second number is y axis(0.0) and the third is the z axis(0.0) and you have to guess because no one made a standard graph that i can find that allows you to know where to point without all that crappy effort people enforce :( but um yea theres my two sense the axis are only there single axis the dot doesn't separate different axises btw

im talking about

^ ^ ^
x y z

carsten neumann
10-28-2011, 02:43 PM
OpenGL doesn't have sphere or cylinder primitives (it's not a raytracer where those are common). The supported primitives are basically triangles, lines and points (with some variations).
So to render a sphere you need to approximate it with a triangle mesh and that method is also what you'd use to render a paraboloid: you calculate points on the surface in a more or less regular pattern and connect them to form triangles.
Haven't tried it but searching for "paraboloid triangulation" or similar should turn up something useful.