nogix

Basically, imagine taking the player's name tag (the thing that renders above a player's head in multiplayer) and rendering just that (nothing else) at the same position onto an external window that is not Minecraft. In my case, I'm not trying to render the name tag, I'm trying to render a health bar. This would be trivial to do in the actual Minecraft window since it uses LWJGL (which does not require you to calculate screen coordinates), but since my external window is a JFrame and uses Java's Graphics2D, I cannot render the health bar without having the screen coordinates. What I'm referring to by "translate 3d to 2d" is world to screen projection.

Nope

I'm trying to make a mod that renders entity health bars in an external window (same width and height as the game window), not the main game window. To do this, I need to convert an entity's position (x, y, z) to 2D screen coordinates (x, y) so I can render the health bar on the external window. The external window does not use LWJGL so I cannot use any LWJGL commands to render the health bar. How would I go about doing this? I tried the method used here, however the 2D coordinates were very incorrect.