So Great Northerner said to just put up what I'm having issues with along with my questions.
First off, my models are made using Sketchup Pro 2015. The finished model is then exported into 3DC to make only the shape. I don't draw a thing with 3DC. This is a area that I stand firm on. I don't like Blender or 3D Max. Sure SU has it's pitfalls, but all 3D programs have their pros and cons.
Scenery objects I have no issues with. I can do those standing on my head blind folded and my hands tied behind my back. Over 8 years I've made well over 300 models for RW, MSTS, and Trainz.
So, with engines, freight cars, and lofts. Upon export one has the option of placing the model center or on the x y z of the 3DC workspace. My models have already been placed on x y z in SketchUp. Do I need to also place the model on the 3DC x y z axis?
Grouping. From what I gather, this has to be done manually for just about everything. I am reasonably sure I'm doing that wrong. So if someone could explain or point me towards some tutorials , please do. Actually, I've had a terrible time trying to find tutorials. Many links to stuff don't work anymore. The DTG Dev Docs have helped a lot, but I'm still not clear on stuff.
In my tree for the groups, the group that I named main is always 3rd down. Pete Willard said it needs to be the first one. How do I move that group above the top 2? I've tried to click and drag, but all that does is put into the first group. The wheels for the model are always back ones first, the front ones second. My bogies always end up being at the very bottom of the tree.
The first four groups always have the names I gave them. After that its a large number of groups with meshes.
So How do I correctly arrange the tree structure?
Shaders. Boy this one is driving me nuts! I just can't figure out how to assign them. I asked about that in another thread. viewtopic.php?f=6&t=22651
Exporting. Apparently the Train Simulator Wizard was introduced starting with 3DC 9.3, my version. Before 9.3 one did a straight export. Docs say for 9.3 and up use the wizard, don't do a straight export. Does that really matter? I've always used the wizard.
I'll start with this, thanks.