saving polly collitions

I am working on a game with a three winged plain (fokker tri plane, same as the red barons), this does not how ever have a low number of faces.

High face count on main object= bad lag (convex hel poly types)

so i placed a box with a round 20 faces (the best to practical ratio) and want to place my plane in it (the plane can then be a ghost). everything i try drops the frame rate the 3 frames per second direction…

how do i do this and keep my frame rate

It’d be best to post a wireframe image of the plane so we can see if you can reduce the polycount. (What is the polycount btw?)

Also what FPS do you get from a blank scene?

Using collision meshes as you described is a common technique, just parent the aeroplane to the box and make sure you select all the faces of your plane and press W then select clear collision to properly remove the collision detection.

My the first pick which is the same plane with the same logic bricks, parents exetra runs at around 25 frames/sec.

once i place it in side the cage, it drops to round 3 frames per.sec and drops frames at a rate of knots.

my plane is still heavy in extra face that i still need to remove (its around 500 faces) but i really shouldn’t be experiancing this kind of drop in frame rate? am i apling the invisiblity incorectly? how is it notmaly done.

thanks for your help

Hmm, that plane looks like it has been heavily subsurfed. Have you used any subsurfing on the model at all? The easiest way to get this sorted out is if you post a face count. Then we can tell you if it should or shouldnt be running slow.

Collision detection on many faces slows things down, but not as much as having many faces in the first place. So the first thing you need to do before you start optimising your models for collision detection is to make sure that they are reasonably low poly, because without that, optimising collision detection isnt going to do much.