I was wondering if anyone can help with this problem I am having. I have made my aircraft, but the various sections of it shade wrong. I thought that if I attached all the various components to the one item that shaded properly, it would fix the problem. This works, but when I then go to group everything together (so I can make a visual interior model as well) and then go to export the model, I get an export failure. If I do not group the items, it exports OK. I really need to group them so I can get on with the interior model.
Any thoughts??

There's a big difference between attaching and grouping.

If you attach one object to another - it's like glueing them together permanently and the software sees only one object.

If you group objects together- they still retain the ability to be edited and modified separately.

What do you mean by shading wrong? Sometimes adding a smooth modifier to an object will solve a lot of shading problems. (Make sure it's the smooth modifier and NOT the smooth mesh modifier) Another trick that solves a lot of shading problems is going into the sub-object edit level, select edge, and look for the "turn" button. Make the turn button active and then select the different edges of the polygons in the object. They'll shift or turn if possible. Having the edges go in different directions can make a hugh difference in how things look. To better see the edges in a polygon you might want to go into the properties window and uncheck the "edges only" box in the display properties section.

I forgot to add, that the vertical tail was made by modifying a cylinder initially created in the y axis, the fuselage a cylinder in the x axis and the wings in the z axis. That seems to be the crux of the matter as you can see that the shadow seems to fall as per the axis it was made in. That doesn't help me now though, because I dont want to remake the whole model if I can help it. I also tried changing and resetting the xyz axis but that did nothing. I may have got my axes wrong, but you know what I mean, that each was created in a different one, and each seems to shadow accordingly. It seems everthing made in the same axis shadows in the same way. The fuselage, bullet and forward bullet fairing, engines are the same axis, the wings and horizontal tail are the same axis. Only the vertical tail is in its own axis, and it alone seems to be correct in shadow with reference to the sun.
Cheers

Thanks very much for your help. I have discovered that the failure to export was due to something else. I hadn't changed anything, but one of the animations went haywire in the updated version and that was causing the failure to export. I feel like a dunce!! sorry for wasting everones time. I have learnt some very uselfull stuff though, so not a complete waste. The aircraft is nearing completion. Just doing some validation of the aerodynamics (not my strongest topic), then ready. A few weeks me thinks. It will be uploaded here of course.
As far as the axis it is made in causing shading differences, there is no doubt about it. I experimented with that, and it makes all the difference. Maybe there is some checkbox ticked in my GMAX options that shouldn't be?? In the screenshot above, the fuselage, bullet, bullet fairing and engines were created in the rear view, so are light at the back, shaded at the front. The wings and horzontal tail etc are in the side view, one wing shades light, the other dark, etc, etc, The gear doors were created in the top view, and shaded like they were in full sun (when they should be darker). I made another set in the bottom view, otherwise identical, and they shaded like they were underneath (i.e were darker).
Cheers