MS-AI Top Decking.....

[Bullethead 12]

The MS Type AI had a humped upper fuselage decking somewhat like a Camel, but somewhat more complicated in shape. The rear end of, in fact, forces the face of the instrument panel. Even worse, there seem to have been 2 rather different versions of it, different on such important things as the positions of the guns and the cockpit cut-out shape, and it's hard to get a full set of looks at either version. But after scouring the web looking at build photos of plastic models, I've finally figured out what one of them looked like from all angles. So, that's the version I'm doing. Now the question is, how to do it?

 

After cogitating over this for a long, long time, and using what I learned doing the cowling, I have finally come up with a plan. So, I have done the preparatory work but nothing permanent yet. Before taking the plunge, I'd like to run this plan by the experts to see if I'm on the right track. So here's the idea.....

 

The basic idea is to use the Hell outta Booleans. In the pick below, I've set all the operands up so you can see how they'll work. Right now, they're all still separate objects and no cutting has been done. When all is said and done, the decking will be the top of the Fuselage object. It will have depressions in the top of it for the guns, and the hole for the cockpit will go partly through what used to be the decking and partly through the original fuselage. I propose to proceed as follows:

 

 

 

1. Make the Notch for the Gun Cooling Jacket

• Boolean cut the decking to match the jacket cookie cutter. Pause to fix redundant vertices.
• Reverse the process to Boolean cut the jacket cooking cuter to match the decking. Pause to fix redundant vertices.
• Delete the cut polys of the decking and the non-overlapping parts of the jacket cookie cutter, so that the notch is lined with fragments of what used to be the jacket cookie cutter.
• Convert the remains of the jacket cookie cutter into an editable mesh, flip the normals, attach to the decking, and weld vertices.

2. Make Notch for Gun Breech

Same process as above but for the narrower, rectangular section of the gun.

 

3. Finish the Decking

Clone and mirror the notched decking to the other side and join the halves, resulting in the mostly-finished decking shape.

 

4. Join the Decking to the Fuselage

Boolean cut the decking to the fuselage, then the fuselage to the decking, dealing with excess vertices in between. Delete the lower part of the decking in side the fuselage, and the fuselage top under the decking, then attach and weld. The decking is now the fuselage upper surface.

 

5. Cut the Cockpit Hole

 

6. Play with Smoothing Groups

 

7. Finishing Touches

After doing the above, I'm going to delete 1/2 the fuselage (decking and all) and build the tail, wings, wheels, and all their struts and wires. Once I've got that all done and mirror and weld the fuselage, I'll have some more notches to cut in the decking, for the MG feed chutes and cocking handles. These aren't symmetrical across the airplane's centerline.

 

 

<P dir=ltr>That's the plan, but you now what they say about how long plans last . Is this a good way to go about it, or is there a better way? Thanks in advance.

 

[ConradB 0]

Looks good to me bro! I cut the pit out the same way. Haven't got to the guns yet, or the big inline 6.

[hairyspin 1]

You're starting to think like a gmax user. Sounds good to me, just beware of overloading the external model with tiny details which can be kept for the VC.

[Bullethead 12]

Sounds good to me, just beware of overloading the external model with tiny details which can be kept for the VC.

 

Thanks. Guess I'll get on with it then.

 

All I'm doing to the cockpit right now is cutting the hole. No details. The guns are pretty plain right now, too.

[Bullethead 12]

Well, I got the gun notch cut out. This was more of a pain than it looked going in, because I wasn't aware that when you convert between ediable poly and editable mesh, AND flip normals, you tend to create a lot of extra vertices each time. I figured extra vertices only showed up on the cut so they took me by surprise later on. I even got to a point where I had like 10 vertices in 1 place and trying to weld them crashed Gmax. I gradually worked this clot down to 2 that still would crash Gmax, so I deleted one and redrew some polys.

 

That was with the 1st, round cut for the cooling jacket. So when I cut the breech, I didn't change things as much as I had before and had fewer problems.

 

Now, tons of smoothing work to do before moving on......

[ConradB 0]

Sorry dude. Should have warned you about the extra vertices. I spend a bunch of time cleaning up the extras before welding things, and sometimes have to redraw a few polys too. I screw up mostly by not setting the Ignore Backround to the proper setting before proceeding, so I drive myself nuts because I usually have to hunt down errors I create.

[Bullethead 12]

Sorry dude. Should have warned you about the extra vertices.

 

I knew I'd get some when I cut polys--that's a given. I just wasn't expect to get more when I converted from editable poly to editable mesh and vice versa. After all, you don't get any when you convert from a standard primitive to an editable poly. Then you also get more when you flip normals. Most of these tend to be on 1 particular corner of the object and each such operation duplicates more of them, so you can end up with a huge clot of them if you don't get rid of them after each operation.

[hairyspin 1]

That's because Editable Mesh is based on triangles. When you convert from Editable Poly to Editable Mesh and later back again, you can find the mesh has been re-triangulated and some of your original polys, especially big complex ones, are now several polys instead. This isn't really a problem, gmax usually makes better mesh than I do, but if the mesh needs tidied up first, just converting back to Editable Poly might really fankle up un-tidied bits

[Bullethead 12]

Well, I got the deck all smoothed out, cloned, and mirrored. Then it was time to mount it on the fuselage. That's where I ran into a problem I can't figure out.

 

I selected the Fuselage, Create Compound Objects, Boolean, Reference, Cut + Refine. This worked great on the front and side edges, but not on the back. See attached pic.

 

Where the rear decking meets the fuselage, it's a complex intersetion of compound curves that Gmax has trouble just rendering even in Perspective view. In User view, it's just total trash. In any case, it doesn't create any new edges in that area and only a couple of vertices on existing edges. The missing cuts are shown in the yellow outlines to the right side of the top view in the pic below.

 

I really don't care much what it does with the square, inner part of the rear decking. That's all just excess material that I'll cut away later when I make the cockpit hole. However, the joint between the outer rear, sloping part of the decking and the fuselage is of critical importance so I'm pretty mad it's not cutting there, especially since I can't visualize it any better than Gmax, so cutting it by hand will be a pain. But I guess I could do it. The problem there is, I still haven't cut the decking to match the fuselage, and I figure any half-ass hand-cutting of the fuselage will hose that operation up.

 

Here's an interesting tidbit that seems related to this problem......

 

When I cut the fuselage, there were ZERO co-located vertices--each blue dot was 1 single vertex. The only "extra" vertices created by the cut were all on the cut where the angled, flat face of the decking comes up through the top of the cylindrical fuselage. In the top view, this cut makes an arc across the front of the fuselage top. In the side view, this cut is a straight line.

 

Anyway, the "extra" vertices were on the new edges of this cut, perfectly in line between where this cut crossed the existing edges. I've already gotten rid of them in the pic, but I've marked where they used to be in the front view. As you can see, they were right in line where the edges of the curved, rear part of the decking crosses into the polys of the fuselage. IOW, the cut made the correct number of vertices, but put the rear ones up at the front on the wrong edges instead of further to the rear and making new edges for them.

 

Anybody know how to get around this problem?

 

Thanks in advance.

 

[hairyspin 1]

The 'extra' vertices are where the edges of triangles making up your polys intersect the mesh of the fuselage. You don't see these edges in Editable Poly.

 

As far as the non-cutting at the rear of the deck goes, there are a couple of things you can do. The first is to make sure you're working with closed mesh - no open ends. The next is more complex, but I'll post on it as soon as.

[Bullethead 12]

As far as the non-cutting at the rear of the deck goes, there are a couple of things you can do. The first is to make sure you're working with closed mesh - no open ends. The next is more complex, but I'll post on it as soon as.

 

I appreciated it. I'm pretty sure the mesh is all closed. I made it out of a box that I just moved vertices around on, made some edges, and extruded from. Never deleted any polys.

[Bullethead 12]

OK, I think I got the problem solved about the rear decking not cutting. It seems to have been a simple fix. I haven't gone all the way with it yet, so I can't say for sure, but it seems to be working pretty well so far. I just wanted to say this now to save Hairyspin some trouble, although if he's making a complex tutorial on a par with is last one, I'd like to see it anyway because it'll be sure to have some good info in it.

 

The reason why cuts weren't working seems to be that the polys of the rear deck weren't planar. They all had 4 vertices that tapered in 2 dimensions from 1 poly to the next. Thus, Gmax didn't know where to cut them. So what I did was divide these polys into triangles, as you can see in the pic below. Voila--a nice, neat cut where the triangles cross each other.

 

Something to keep in mind when trying to cut compound curves......

[hairyspin 1]

Good one, BH! And I have made another tut on this very problem, coming shortly on another thread...

[Bullethead 12]

Good one, BH! And I have made another tut on this very problem, coming shortly on another thread...

 

I look forward to seeing it. The Gmax commands you include in such things are always jaw-dropping.

 

Anyway, I think the decking's done, FINALLY! As shown in the pic above, the cut as made was rather jagged, so it required a bunch of vertex and edge tweaking. Then I cut out the cockpit hole, and that required a lot more of the same, plus mucho playing with smoothing groups. I was unable to iron every wrinkle and shadow out completely from every angle, but I got it looking pretty good from almost all angles. While I'm sure the remainder is mostly my lack of skill, I do think there are some limitations of the medium here, trying to model complex shapes with just flat surfaces.

 

So here's the finished product. As stated earlier, I still have to cut some notches for the feed chutes, but that won't happen until far down the road.