Loading additional data in realtime?

r2d2 · Post by **r2d2** » Tue May 17, 2005 7:56 pm

Hi,
It's again me... i know ^^
I tried to load additional data into my Irrlicht application with the pthreads lib while the mine thread displays a landscape and while the camera is just moving a little bit... nothing very complicated... when trying to load additional data... i get a really heavy performance impact (FPS at 0 from around 100) so my question is... how are the pros managing that... are they loading everything into memory before the game starts? I am especially referring to games like Far Cry... I think everyone knows the huge islands... or swg... when you run around in the nature you normally don't notice any loading...
Thanks in advance for any hints... R2

mm765 · Post by **mm765** » Tue May 17, 2005 10:27 pm

which driver are you using ?
and what kind of data are you tryingo to load (i assume models/textures but want to make sure) ?
and how do you synchronize the loading thread to the main-thread (if at all) ?

AlexL · Post by **AlexL** » Tue May 17, 2005 11:36 pm

I'm not sure I completely understand what exactly your trying to do with loading the data. But you may want to take a look at the source from the Feburary 2005 GDM, it contains an article on late-binding data and from reading the article over again it might be what your trying to do. You can find the source for it here :: http://www.gdmag.com/code.htm :: Hope this helps you

r2d2 · Post by **r2d2** » Wed May 18, 2005 9:42 am

Yes mm765 i want to load especially models. I don't synchronize it because i didn't think that it's necessary for such a small example.
I will have a look at it AlexL

mm765 · Post by **mm765** » Wed May 18, 2005 2:09 pm

...double post

mm765 · Post by **mm765** » Wed May 18, 2005 2:12 pm

hmm...too bad you didnt say which driver you are using because with what you wrote im a bit confused.
using the pthread-lib hints at linux but then if you would use opengl your app would prolly crash if you try to load something with a texture while youre rendering because the loading thread couldnt use the same opengl-context if you didnt change your irrlicht-lib to make it a shared context and so on.

but you could also use pthread-win32 and use directx which then would probably halt the rendering if a texture gets loaded while rendering until the texture is fully loaded (which would explain your 0 fps).

and of course it could be you made it so that your loading thread only runs while youre not rendering (which i meant with synchronizing) which would make using threads quite senseless

soo..which one is it ?

r2d2 · Post by **r2d2** » Wed May 18, 2005 4:29 pm

Sorry... i totally forgot to mention it... i am using Direct X 9.0...

mm765 · Post by **mm765** » Wed May 18, 2005 6:04 pm

the problem then is the texture locking which is hard to work around in directx with irrlicht. it is easier for opengl (a solution for opengl is included in nx) .
so if you can live with using opengl id suggest using it.

if you need directx then you need to change the dx-texture-class so that it holds a buffer with the image and doesnt directly upload the texture upon loading from disk but at the point it is used.