BASIC LIGHTWAVE TUTORIAL NUMBER TWO
Constitution Class Secondary Hull
My tutorials are made with Lightwave 5.6 in mind, but the concept will work with other versions, as well as Inspire 3D
Well here we are again. In this tutorial we are going to make that often tricky starship structure: the secondary hull. And our featured tool for this task will be Rail Extrude. Like Lathe in the previous tutorial on Constitution saucer sections, Rail Extrude is an useful and very essential tool, and it's as equally versatile. Before we start I'll make the following, perfunctory declaration:
-This tutorial is aimed at people who have at least a rudimentary grasp of the concept of Lightwave and its interface. If you're an absolute beginner I suggest you visit the site below to consider some very useful Lightwave tutorials: This site provides links to tutorials where you can learn everything from explanations of basic tools for novices, and some more advanced techniques, such as spline patching, character modelling and special effects:
Right let's begin. Again I shall be using the method: Objects>Box, and so forth to point you to various menus and functions in Lightwave. In this instance, I would mean you to go to the Objects tab, and then the Box button (etc)
Step 1
As in the other tutorial, study this screencap to configure Modeller to our mutual compatibility.
Step 2
Firstly, no other ship in sci-fi history is as recognisable and familiar as the original Enterprise, so if you're going to make a good mesh of this structure, it has to be precise in form and shape. There are several methods to use when constructing such a difficult and precise shape like the Constitution Class secondary hull, some more simple than others. You could for example create a disc with 20 segments, and play around with the Stretch and Taper Tools.... I don't think you'd have much success, and it would also be a hideous task. You could also create and manipulate a basic spline cage. But for the poly modeller Rail Extrude is the guy you want to use, it's my preference in this kind of scenario anyway. It is fast, and pretty simple, and yields, I think you'll agree, very acceptable results. So, to begin with, download this picture:
(Click on the thumbnail to open the image, then Right Click, and 'Save Target As' - for Windows users)
Unlike the saucer tutorial, you will need this picture as a visual guide when creating the Points. This is a little more complex this time around as we'll be creating several different splines.
This picture isn't the greatest example, but I have nothing better at the moment. What we are going to do is load this into the background of Modeller to do some close up Points work, using the picture of the secondary hull to trace around. It needn't be fantastically perfect, it can't be, part of the hull is obscured by the saucer in the overhead view - we just need it as a guide, that's all.
Step 3
In Modeller, go to Display>Backdrop. You'll see various options here, but all we need to worry about is where we're going to put the picture.
Study this box. At the top, next to 'X Image', hit the Load button. From here, browse your hard drive to find the picture of the Constitution Class you just downloaded. When you have, scale it up a bit. In this example I input 200M in the Height box, but the actual value doesn't matter much, you can scale the final model according to canon value of the starship at the end. The NCC 1701 Enterprise came in at 289M.
Leave everything else as it is, then click Okay.
When pressing (5) on the numeric keypad, and with using the zoom keys (comma, period) you should eventually see this, with the Connie picture in the bottom right hand pane. Press (3) and zoom in on that image. We are going to trace the contours of the secondary hull with a series of Points. What we want to do is create two 'splines' here, one for each edge of the secondary hull. First go to Polygon>Points to enter Points creation mode. Use the Right Click button of your mouse to create the Points, like this:
I hope you can make out the Points in this picture. These images are quite high res and I had to compress them a little for web space purposes. Anyway, they are the little blue dots following the line of the hull. You'll notice that with these Points I ignored the hull's 'undercut' section. This is because, eventually, you will have to use a Boolean Subtract operation later on to get that effect. Don't worry about it for now.
Step 4
Okay, now along each line create a separate curve, like this:
Use the Drag tool as necessary to iron out any imperfections in your curve, such as the odd crooked area. Make sure it's as pure as possible.
Step 5
Now, move to another layer by clicking one of the little rectangles towards the top right of the screen. This bascially means that we're working on another 'canvas', but the other one is still there, in the background. We also have to move to another viewport. First though, bring up that Backdrop panel again (Display>Backdrop). Switch to 'Y Image', and from its drop-down menu select the Constitution image. Before clicking Okay, make sure it's retained its originally configured size properties by specifying 200M in the Height Box.
Now press (7) on the keypad to switch viewports to Top. With the arrow keys line it up so you can get a good view of the top of the secondary hull. Along one edge only trace the hull contours with another line of Points. Compensate for the missing part of the hull by making your best guess. Also extend the Points a little beyond the aft section of the hull, where the shuttle bay is. That part will be modelled later. Use the picture below to see what I mean. When you're done, we need to then perform a Mirror operation.
Go to Multiply>Mirror. You can see in the picture where I've placed the Mirror line, right down the centre of the hull. The Mirror Tool is very useful in this instance, because it saves us from redrawing another line of Points for the other side of the hull, which is in this case symmetrical. What the Mirror Tool does is create an exact copy of your object on the other side of the Mirror line. So when you have the Mirror line in the right place press Enter. And there you have it.
Step 6
Now, like before, create a curve along each line of Points. Then, rotate your object 90 degrees, like this.
Line it up with the hull in the bottom right pane, and then Copy/Paste the curves from before into your current layer. Line everything up so it matches the shape of the secondary hull. You should have something like this:
This is the basic shape of the secondary hull were are going to make. If you haven't done so before, save your object to your hard drive. It's always important to do this as often as possible. There's nothing worse than loosing your work to a crash or power failure. Believe me, it does happen.
Step 7
We're in good shape now. So we can get rid of the Constitution picture. Go to the Backdrop box, and select 'None' for X and Y image. We also now need to move to another layer. Leave your four curves in the background for now. What we have to do next is create a simple disc, with a single face. Choose as many sides as you deem necessary, say, 30 would be enough, for instance. What I want you to do now is use the Size and Move tools to scale the disc and line it up to intersect with the front end of your curves (still in a background layer), like so:
Give this disc a name and a surface. Such as 'secondary_hull1'. Turn smoothing on, to an angle of 30 degrees.
Step 8
Right this is where the magic comes. We are going to perform an operation called Multiple Rail Extrude, extruding the disc through a shape which we have defined with the four splines. Go to Multiply>Rail Extrude. The options here are important, as it greatly determines the form of the mesh we are trying to create.
From the buttons at the top of the box, select 'Lengths' and 'Automatic', leaving 'Knots' and 'Uniform' unselected.
Basically, with tools like this, one usually finds their way by playing around with the various settings to see what results they get. That's the best way to learn. But let's just examine what options we have here... Firstly we want to set Segments to 'Lengths', rather than 'Knots', as Knots follow the Points. 'Automatic' and 'Uniform' is in regards to how the disc divisions follow the curve. You can choose 'Automatic', as I have, or specify 'Uniform', and insert a value for how many divisions you want. In this case I would use at least 20, unless you're going for really low poly results.
The 'Strength' box signifies how strongly the extruded shape adheres to the splines. We don't need it to be Point perfect, our splines are only a guide for the extrusion process, and they are only gentle in shape, there's nothing that complex about it. So I've set the Strength value to be 0.0, but it's down to you, and even if you input a value you won't notice a great deal of difference.
'Orientation' should be deselected here. We want each division from our disc to remain parallel to the original one.
'Scaling' is on. We want the extruding disc to scale itself according to the curves.
Step 9
With everything set up, hit Okay, and off we go. Hopefully you'll come up with something like this:
This now looks more like the secondary hull we had in our original vision. Plenty more work has to be done in order to create your fully functional Constitution Class secondary hull, but at least now this technique gives you a chance of creating the secondary hull with some degree of accuracy and control. And I think you'll agree this is a relatively straightforward process - with practise. You should also take note at how much potential Rail Extrude has. It's excellent for more organic objects, such as pipes and tubes. Anything is possible, depending on the shapes of the splines you draw, and what shape you wish to extrude. Here we used only a simple disc, that's because the hull is cylindrical. But experiment with the tool and its settings and see what other cool stuff you can come up with.
Of course there's still some way to go to complete your secondary hull:
But as we follow the steps in learning the key techniques needed to build a complete Constitution Class ship, the next tutorial will be introducing such fascinating tools as Stencil Drill, and Rail Clone, as we seek to understand how to apply windows to the hull, as well as creating and stencilling the ship's name and registry...
Until next time...
Tutorial 1 | Tutorial 2 | Tutorial 3 | 3D starships Index
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