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jPCT - a 3d engine for Java => Support => Topic started by: Hoagie on July 27, 2005, 06:49:58 am

Title: New to jPCT - Is it for me? Can I do...?
Post by: Hoagie on July 27, 2005, 06:49:58 am
Hello all!

I was just pointed to jPCT from the Java3D forums at java.sun.com.  From what I've seen so far it is exactly what I've been hoping to find!  I'm new to whole 3D thing, so I'm wondering if jPCT is for me and if it can do a few things I'm hoping to do with my first project.

First, is it for me (a new 3D programmer)?  Is it really something that I can sit down with and understand how the concepts I learn work with the engine, or does anyone have a suggestion for a more "educational friendly" engine?

Provided the first part is a resounding "yes", I'm wondering how I might use jPCT to implement a game I am wanting to build.  Think Final Fantasy Tactics (or any tactics game) or a game similar to Ragnarok Online (if you've played, and is actually the graphics source for my tinkering).  I'm wanting to construct a simple tile based ground, which will be the "3D" of it -- full rotation, zoom, all that jazz.  For the sprites however I have simple 2D sprites.

While playing with jME some I was working with BillboardNodes to try and accomplish this, but had little success with my knowledge at the time.  Does jPCT have a similar concet, or can anyone suggested some methods I could investigate on how to render a 3D ground with 2D sprites overlayed on top?

Many thanks for any help, tips or suggestions!

Hoag
Title: New to jPCT - Is it for me? Can I do...?
Post by: EgonOlsen on July 27, 2005, 08:11:06 am
The basic idea behind jPCT is to keep things simple, so it should be suitable for beginners. It tries to hide all the "don't care" stuff from the user...something that others don't IMHO.
If it's suitable for you and what you have in mind...i don't know. You can do billboarded objects and you may emulate sprites with that. You can't do parallel projection, it's always perspective. This may or may not work for your project.

Hope this helps.
Title: New to jPCT - Is it for me? Can I do...?
Post by: Hoagie on July 27, 2005, 06:30:45 pm
Thanks!  I've started to tinker with getting a jPCT test put together to play with the things I'm hoping to do.

Although the view is always perspective, a BillboardNode should still always face forward with unchanging dimensions - right?  So spin and pivot all you want, it will still face the observer.  Am I remembering this correctly? :)

Readying through other posts here, what do you think about bliting the sprites onto the view?  This might be the easiest way (I hope not, but might be) for a 2D sprite on a 3D ground/background.  Collision would probably be a pain to manage between the 3D world and the 2D objects.  How would the performance maintain with (say...) 100 sprites on the screen?

Hopefully I can get the ground data rendering in the next day or two... okay, maybe by the end of the weekend.  Then I get to figure out the sprite craziness. :?

Thanks for any info and help!
Title: New to jPCT - Is it for me? Can I do...?
Post by: EgonOlsen on July 27, 2005, 06:42:46 pm
Yes, billboarding has nothing to do with perspective projection. About mixing 2D blitting and 3D graphics, you may have already noticed from reading the other threads about this, that it has some problems....i may be possible in one way or another, but not exactly fun IMHO.
Using billboarded, textured planes for the sprites may result in problems with the software renderer, because you have to set the billboarded objects to transparent (at a high value, for example 6) and the software renderer handles this slightly different for performance reasons. So using OpenGL, the sprites will most likely look fine but using software, the may look a bit too dark. I just wanted to mention this in case you are wondering.