Combining multiple nodes into a single OctTreeSceneNode

eudemon · Post by **eudemon** » Mon Sep 19, 2005 2:19 am

I'm under the impression that OctTreeSceneNodes optimize meshes, combining multiple polygons into into one if possible, and rendering only those polygons that are within the FOV at any given point.

Is it possble to combine multiple meshes into a single OctTreeSceneNode so that they are optimized if they are touching in the scene? Thanks.

bitplane · Post by **bitplane** » Mon Sep 19, 2005 3:27 am

you could always just add them to one of these:
http://irrlicht.sourceforge.net/phpBB2/ ... php?t=8596

Guest · Post by **Guest** » Mon Sep 19, 2005 4:36 am

I've just skimmed that post, and it looks interesting. Might be a little in depth for me though; I'm mostly just using the irrlicht libraries as they are, and haven't really explored their source code much yet. This might be just what I need though.

eudemon · Post by **eudemon** » Mon Sep 19, 2005 5:17 am

The above post is mine. Just read that thread a little closer, and it looks like it's basically a more efficient culling algorithm. That would help with my problem.

Basically, I'm dynamically generating a map, for a strategy game. It's made up of square tiles. Problem is, a map that is 50x150 tiles makes for 50*150*2=15,000 polygons. Plus the borders between tiles have their own meshes, in order to make the transition between two types of terrain look better. Plus the HillPlaneMesh that makes up the water in the map. If there was a way to use the existing optimization abilities of an OctTreeSceneNode to combine unnecesary polys, I would get much better performance.

Though I may be misunderstanding just what a OctTreeSceneNode does, so please enlighten me if I am...

JP · Post by JP » Mon Sep 19, 2005 10:55 am

Hi, i had the same efficiency problems with my 3D maze i was building for my FPS game for my final year uni project, originally i used smgr.addTestSceneNode() to build up the walls of the maze, but when you have a 20x20 cell maze, and each wall being made up of 25 testSceneNodes you get..... well lots of polygons! And the lag was horrific, so i realised i needed a much better way of building the maze.

I had originally thought i could somehow make my program output a Quake 3 map and then load it with Irrlicht, but that looked rather complicated, but i've basically done the same thing, but with .x files. They're not too hard to get to grips with but i havn't quite got them working fully properly yet, still some niggling problems. If you want to look into this more i can give you some links to sites that help explain the .x files and how they're constructed. It really really cut out the lagging from my program, it's all very smooth now and i can have even larger mazes!

eudemon · Post by **eudemon** » Mon Sep 19, 2005 3:09 pm

Thanks JP, that would be great. Creating a single x mesh for the map would be much faster in both loading and rendering.

JP · Post by JP » Mon Sep 19, 2005 11:45 pm

Here's the thread on the jIrr forum (Java binding for Irrlicht which i'm using) that i started, originally asking how to make a floor for my maze, i was given a simple mesh to do so and it all leads on from there.

https://sourceforge.net/forum/forum.php ... _id=383520

Here's the website which i used to get help on the .x format, i think it's linked to in the above thread aswell.

If you get confused or have any questions then let me know!