No, you dont need attachment points. You need something like this in the gonfig file of the relevant interior
cameralist
{
camera0 -0.04,4.196,0,0,-0.1
camera1 -0.311,-0.169,0.07,1.38,0.004
camera2 0.075,-0.711,0.067,3.15,0
camera3 0.16,2.389,0.267,3.15,0
camera4 0.235,3.292,1.545,-7.427,-0.082
camera5 -0.912,3.212,1.545,0.177,0
camera6 -0.899,2.041,1.545,3.015,-0.064
camera7 0.057,3.139,0.3,3.15,0
camera8 -0.336,3.612,0.2,-5.705,0.34
}
(But with the numbers 'tabbed' across to be inline with the other entries in the config file)
The numbers after each camera number are similar to grid references and allow Trainz to work out the positions of the camera. Start small and add a couple of new camera positions to the existing config file and see the results before adding anymore. You may need an element of trial and error to get the positions just right