How does HnH's rendering work?

[bradyterp]

Hi, after playing HnH for several years (this is my alt's account-- I lost my main's password), I have recently been inspired to actually do something with my C++ experience. I now have a client and server with player movement and a tile system... but it's in top-down 2D. I've been researching how HnH goes about it's rendering, and I read something here that says that HnH is actually rendered in 2D, not 3D like I previously have heard. I have a few questions for Jorbtar or anyone else who's mucked about in the client:

1) How does HnH handle the rendering in OpenGL? Does take advantage of 3D isometric or is it pure 2D? (wireframe mode had me wondering)
2) How does HnH handle collision detection?

I'd love if someone could answer these questions to help out a fellow indie developer. Thanks

Note: I know HnH uses Java and JOGL, but that shouldn't matter much. I'm currently using freeglut and regular OpenGL.

[Nummy]

It's using openGL as 2D but openGL is drawing everything as 3D textures with locked z coordinate. Something like that.

[MagicManICT]

I believe most everything is handled server side in HnH. This is evident when a lag spike hits and you keep walking right through cliffs, walls, houses, etc. The client only renders and catches input. I think the picking algorithms are even handled server side. This means you're going to have to ask loftar about specific algorithms used.

If you'd like to pick loftar's brain a bit, you'll have to try to catch him on IRC and he likely won't have too much time, but he's always been pretty good with answering questions if he has time. He's been pretty busy with work on Salem, though. Good luck in your work!

[bradyterp]

I believe most everything is handled server side in HnH. This is evident when a lag spike hits and you keep walking right through cliffs, walls, houses, etc. The client only renders and catches input. I think the picking algorithms are even handled server side. This means you're going to have to ask loftar about specific algorithms used.

If you'd like to pick loftar's brain a bit, you'll have to try to catch him on IRC and he likely won't have too much time, but he's always been pretty good with answering questions if he has time. He's been pretty busy with work on Salem, though. Good luck in your work!

Thanks! I'll try to see if I can find him although I doubt that he'll want to share his prized algorithms. But who knows...

It's using openGL as 2D but openGL is drawing everything as 3D textures with locked z coordinate. Something like that.

That's what I've heard. I'm new to OpenGL so I'm trying to figure this all out. Thanks!

EDIT:
So this isometric view is a bit more tricky than I thought. I guess what they did for HnH is that they used 3D, cut out the z-axis, and used billboards for everything instead of models. The only thing in the game world that actually appears to be textured and not a billboard are the ground tiles. After looking at the old development blog, it looks like they also used to use textured palisades (which looked horrible).