[1.7.10]How can I cover world location to screen pos to render?

[End_KG]

I wanna render player sign(like nameplate ) onto screen whatever how far the player is,but i've tried many ways to achive it but i was faild.

 

There are two ways I tried but faild before. 

1. use gluProject to map player location to screen pos,as a result,I got an incorrect screen pos.

2.render infos I need into world directly when RenderWorldLastEvent was fired,as a result,those infos didn't render when I am far away.  

 

i wonder that is there a way to let me cover 3d coordinates to screen pos and render onto screen whatever how far the player is?

 

I am sorry for my poor english and thanks a lot!