big object not rendered

[jontan6]

Hello, I have a large object. building actually.




but at certain angles, it is not rendered


any settings i can set so that this is prevented? i have other big objects too behaving this way =)

thanks

[JP]

It'll be to do with frustrum culling. What format is the model? Some formats don't create good bounding boxes for the models and so they get culled a bit eagerly.

An easy test would be to render the bounding boxes and also to turn off the frustrum culling using node->setAutomaticCulling(EAC_OFF); (though this is something you shouldn't use as a solution, just as a test to see if this is indeed the problem, because otherwise your performance will suffer as the model will be always rendered, even if it's directly behind you and not visible at all)

[jontan6]

the model is OBJ i put together in irredit

i tried inside irredit changing automatic culling properties, when set to box, it disappears. when i set to off, frustrum_box, and frustrum_sphere, its ok.

is it ok to use frustrum_box/sphere?

thanks!

[JP]

Yeah looks like frustrum box is the sensible option;

"box", // camera box against node box
"frustum_box", // camera frustum against node box
"frustum_sphere", // camera frustum against node sphere

but box seems to be the default... possibly it's more efficient but not quite as accurate as the frustrum.

but anyway, did you check that your model's bounding box looks sensible? i think in irredit you can make it display things like that.

[jontan6]

thanks so much JP for the help.

Yes the bounding box shown in irredit seems ok. it just bounded exactly the whole building. i will just use frustrum_box for selected objects. this problem seems only occuring in very big object, which is just few in my scene.

thanks thanks

[rogerborg]

Note: Frustum, not frustrum.

I keep doing that as well.

[JP]

wow... i'm sure i've alway seen it as frustrum, but maybe that it's, i've been seeing it as frustrum, adding the r in myself

well i think frustrum sounds better anyway...

[rogerborg]

Frustating, isn't it?

[Jallenbah]

wow... i'm sure i've alway seen it as frustrum, but maybe that it's, i've been seeing it as frustrum, adding the r in myself

well i think frustrum sounds better anyway...

I thought it was Frustrum too. Wierd.