so I'm working on a three.js project where I have the floor of a building saved as a collada file, there are additional collada objects saved into the scene in the form of some air zones (cuboids basically). You can move around the model using WASD and the mouse, however as the camera moves around the model, depending on the angle, some of the building floor or rooms will turn invisible allowing me to see the mesh plane at the lowest level of the model. I have been looking through SO for advice, and in general the COLLADA issues seems to be related to not having material double sided set properly, I have made the rooms and my floor double sided to test this, however this doesn't seem to have fixed the issue.
The prototype can be found at: http://danu2.it.nuigalway.ie/WebGLProject/
In the model I've temporarily raised the air zone cuboids while testing that the issue wasn't occurring due to mesh clashes. This doesn't seem to be the case.
Does anyone have any advice on what the likely culprit is, or a potential solution to the issue?