Flat and Smooth Shade

i have drawn a shape using following parametric eqns:
x=2(cos(a))^3(sin(0.5b))^5
y=2(sin(a))^3(sin(0.5b))^5
z=2(sin(0.5b))^5cos(0.5b)
drawn using GL_QUAD_STRIP and 4 vertices. in 2 for-loops and it looks perfect in wire frame mode. however, when render in flat/smooth shade, only the wires have the effect and not the entire polygon. i know it has something to do with my normals but i dont know what exactly is wrong… i used the crossproduct formula in the redbook. anyone pls help and if need my code i will be glad to send to u… thks.

Hi !

Make sure you have the coordinates in the correct order for the strips, if you get them wrong some triangles/quads may have the wrong winding order and this can mess up the result.

Mikael