Performance problems due to high RAM consumption

Homer · Post by **Homer** » Tue Apr 06, 2004 4:57 pm

Hi,

I'm using a .3ds mesh with 23290 triangles displayed by an OctTreeSceneNode as my game level. When the mesh is completly loaded into my program, it consumes about 330 megabytes of RAM, which is no problem for my machine, but for computers equiped with lower amounts of RAM. Why does Irrlicht need so much memory for a small 3ds file of 0,8 MB and textures of 10 MB? Is there any chance to optimize this?

Blivvy · Post by **Blivvy** » Tue Apr 06, 2004 11:46 pm

The fourth parameter of addOctreeSceneNode allows you to set the minimum number of polygons needed in each octree node. If you are using the default value (128 polygons) then because your mesh has quite a few polygons, the octree that is generated is going to be quite deep and require a lot of memory. Try setting this value to 512 or 1024 polygons to reduce memory requirements.

Homer · Post by **Homer** » Wed Apr 07, 2004 1:33 pm

Thanks for your reply, I didn't thougt of that yet and just tried it out. I've also tried to use an AnimatedMeshSceneNode instead of an OctTreeSceneNode, but the lowest memory consumption I could achieve was still at about 323 MB.

Blivvy · Post by **Blivvy** » Wed Apr 07, 2004 6:37 pm

Ah that's a shame

. The only other thing I can suggest is trying the same with any triangle selectors you might be using. Is it definetly the node containing the level mesh that's consuming all your RAM? Good luck solving you problem!

Homer · Post by **Homer** » Wed Apr 07, 2004 7:09 pm

I've commented everything out, except the line

Code: Select all

levelMesh = sm->getMesh("map.3ds");

and the necessary lines, of course. The program still needs 300 MB of RAM. Would be nice if niko could have a look at this.

Guest · Post by **Guest** » Thu Apr 08, 2004 3:55 am

Weird. Does it matter at all if you run a Debug vs. a Release build?

Homer · Post by **Homer** » Thu Apr 08, 2004 2:12 pm

Anonymous wrote:Weird. Does it matter at all if you run a Debug vs. a Release build?

Switching between Debug and Release makes no difference at all. It has to do with Irrlicht's mesh loader code, but that exceeds my humble c++ knowledge.

Domarius · Post by **Domarius** » Thu Apr 08, 2004 2:33 pm

We know Irrlicht can load .BSP files efficiently - is this the only documented case of loading a 3DS as a level and comparing the memory usage?

Caecus · Post by **Caecus** » Fri Apr 09, 2004 7:17 am

Irrlicht also does nasty stuff to md2's. Check out hellow world example it uses over 20 megs of memory for a 500k file.

The reason behind this is irrlicht is storing full vertex coords basicalyl for every frame (along with normals). The md2 format itself cuts out a lot of this and uses scalers and such to make each vert only 3 bytes. Irrlichts verts end up being more like 20 I think.

Domarius · Post by **Domarius** » Tue Apr 13, 2004 11:41 pm

That actually sounds like a serious problem - how could anyone make a game run decently on anyones computer like that?

Domarius · Post by **Domarius** » Wed Apr 21, 2004 2:09 pm

...so... does anyone agree/disagree?

I'd like to know Nikolaus's thoughts on this.

Homer · Post by **Homer** » Wed Apr 21, 2004 2:17 pm

Domarius wrote:...so... does anyone agree/disagree?

I'd like to know Nikolaus's thoughts on this.

Me too, but it seems that he's very busy at the moment. I'm also waiting for his response to my email regarding this topic.

niko · Post by **niko** » Sat Apr 24, 2004 12:27 pm

Wow, 330 MB is a lot, don't know how it gets that big. Did you try to convert it to another file format and check out if the memory usage is still that high? And about a mail: Hm, I think I did not recieve a mail on that topic... At least my Outlook keeps telling this, sorry.

Homer · Post by **Homer** » Sat Apr 24, 2004 1:05 pm

Yes, it's nearly the same when I use the x-format: still 300 MB. Regarding the mail: I've sent it on 16th of April to your sourceforge-account. Hm, maybe it got lost somehow, so I'll resend it.

Domarius · Post by **Domarius** » Mon Apr 26, 2004 5:08 am

Cool, Niko is here

Niko, are you able to load levels, meshs, etc, and NOT experience such huge RAM usage?

If so, then its possible for us to as well, if not, then I guess it's a bug and we'd have to wait for it to be fixed.