maybe something wrong in model ? it happens for me for example with backpack (BIS Arma1 backpack ), i wanted make Backpack - there is problem in Bulldozer, when backpack is on soldier, all is okay
similar problems i have on some of my RPG (i used Arma1 RPG7 + i made PGO7 scope for it)
it happens on some other models too
cannot say why , i had no problem in previous version of tools (not last one 2.51)
what's more funny, when i scale object - for example scale 2.0 - there in no problem in 50% or on some model still problem
when i copy-paste mesh to new P3d, still problem remains
in game models work okay, problem is only in last Bulldozer
i happens like there was "virtual alpha channel wall"
As Pufu said, it has to do with the near clipping plane for the camera. You can control what is cut away by balancing the distance of the camera from the object with the zoom level. There appears to be a sweet spot.