Possible problems with shaders in http://playcanv.as/p/wQgQBgkE

If you look at: http://playcanv.as/p/wQgQBgkE you will see sometimes that straight lines appear. I use a Sphere Icosahedron mesh FBX generated from Blender, and a shader “Flowers Vertex.GLSL” in PlayCanvas 3D HTML5 Game Engine to deform the vertices. I would like to get rid of the straight lines, but I am a beginner shader programmer, and I’m not quite sure what to deform in the Sphere Icosahedron to get my surfaces looking right. I realize that I may need a surface that is a sphere wrapped around more than once–should I deform a flat surface? I think it has something to do with sin/cos/atan and the conversion to/from spherical coordinates. If this is a stack overflow question, let me know.

I was able to use a Sphere UV and get a better effect. Slower though. Hmm.

Can you use vertices position instead of UVs to get their relative angle to center and then manipulate?
As UVs will be going from 0.0 to 1.0, and you will have to take looping in account, and it just feels like more complicated, where vertex position initially shall be good starting point.