An Alien Spaceship

Written by Philip Staiger
Copyright (c) 2001 Template Graphics Software, Inc.


I've been asked a few times for tutorials on how to build a space ship, particularly by gamers who want to add their own spacecraft, weapons or other props to a game.

It's been done, and I keep referring to several great artists' sites where Amapi is used for designing spacecrafts, such as


 
 
www.deepcold.com (making realistic models for animations)
http://users.skynet.be/deboeur/Tutorial  (awesome spaceship tutorial)
 

 
 

Making your own Vehicle

There are various different ways and techniques to build a vehicle, whether it's a spacecraft or airplane or car. You can imagine building the various elements of a car, for instance, with construction curves. Make the hood, the fenders, the trunk, the doors, the roof, etc... and then assemble them all into one object. Amapi offers great tools to create surfaces from various curves, such as a section contained between two curves (birail sweep, aka double-sweep), or a set of 2 or more sections connected through 2 or more profiles (Gordon surfaces), or even a closed region made of 1 or more curves connected end-to-end to make a closed loop (Coons patch). And that's just the beginning. You can easily do extrusions from a section, sweeps, and connections across multiple curves to create meshes. (Ruled surfaces).

Another method, which I like a lot, is to make it with the Extrusion tool (and/or Sweep tool). Starting from a single object like a cube, you can extrude a facet of the solid to make a wing, then another for the other wing, the cockpit, the fuselage, laser guns etc... Of course, here you have to think differently - think in very low polygon terms first. You can later use some of Amapi's smoothing tools to give it a more organic look.

Using the Extrusion tool

Ok, let's start from nothing and place a cube into the scene. Using the Basic Wireframe mode (selectable in Preferences>Workspace), and the Workshop interface (also known as Natural Design Interface), I select the construction toolkit, and hold the cursor over the sphere (don't click), then select the cube from the popup. Click in the bottom of the screen to place the cube, move the cursor sideways to set the size of the cube, and click again to finish.

We may want to make the cube flatter, so use the Scale tool in the Assembly toolkit.. This normally operates as a proportional scale, i.e. scaling uniformly in all 3 main axes directions.

Just hit the spacebar and you'll see one of the two axes disappear, hit the spacebar again and it switches to the other axis. Orient your camera up or down or sideways with the arrow keys if you want to see the third axis. This way you can select, for instance, the vertical (green) 'Y' axis to make it shorter (less high)


 

And thereafter scale it along the 'Z' axis to make it a bit longer in depth.


 
Hit Enter or swipe the tool away to the right edge when you're done. Hit Enter again for a quick render. Here's the base block.
Now, switch to the Modeling toolkit. We'll use the Extrusion tool next.
Click the Extrusion tool, select a front view (hit numeric "2"), then use the right arrow key to turn a little to the side and  have a clear shot at the right side wall. Click the side wall.
Hit the Spacebar so the movement and extrusion gets confined into just one horizontal axis (red = 'X').
Make a short extrusion and click once, then hit Return to finish. Do the same amount of extrusion on the other side wall, opposite side: rotate your camera with the arrow keys, click the extrusion tool, select the side wall,  extrude by the same amount.

Now how do I know exactly how much extrusion I gave it the first time on the right side? Well, if you looked in the lower left corner while doing the extrusion, you could see the numeric values indicating the depth of extrusion. Use the same value.. Or,  use the Measurement  tool in the control panel; at bottom 


 
Once in the measurement tool, click the top right corner and bottom right corner of the extruded block and you'll see the distance there (vertical height). Click the top right corner and the corner to the left where the extrusion started from, and you'll see the horizontal extrusion amount. (0.08 m in this example)

Note: you can change your measurement units in the Preferences menu.

Swipe the tool away when done with the measures. 

Now, if you are picky and absolutely have to have that left-side extrusion depth be the same as the one on the right side, one way to adjust the depth on the left is to use the scale tool in non-uniform mode (again, with the spacebar to toggle to just one axis). 

Before using the scale tool, throw the lasso over the 8 points on the right side. (to get the lasso selection cursor, Option-click on Mac, Right-click on PC)

 
Now these 8 points are selected,
and you can click the scale tool, and hit the spacebar to toggle along the horizontal axis. 

Scaling will occur only on the selected subset. The bounding box contains only the 8 selected points, not the whole part.


Notice however that the center of the 8-point selection subset is where the 'X' reference point is located by default, and we don't want to scale relative to that center point. Thus, click the right mouse button (Option-click on Mac) and select one of the 4 points on the right side of the 8-point subset selection, i.e. one of the points that were part of the very original cube before the extrusion was made.


Then you can click and move the mouse to resize the box, and verify in the lower left corner that the dimension along the red 'x' axis is also 0.08 as shown in the measurement tool. You can even hit the TAB key and enter that value numerically.

When you're done with that, click the entire block to undo the 8-point selection. 

You can use the measurement tool again to check that both sides have the same extrusion depth.

Ok, now back to more extrusions. In exactly the same way as we've done before we can extrude a short block on the front of each extruded side block. This time however I didn't use the spacebar to lock into a single axise, so it's possible to make it go a little shorter and smaller at the same time. These could become the engine exhausts.

Here's what it can look like when using the cartoon shader ("Create a Style" in the shader palette).
or here's a slight variant, with draft techno look instead of clean cartoon
Alright, let's get more serious now. Look at the flat top, let's make a short angular extrusion there (no lock into one axis, keep it going into both directions).

We want to work this into a slanted cockpit windshield. The right  side is going to be the 'front' side of the cockpit (i.e. nose of spaceship). Click the right mouse button twice for the bull-s eye cursor (Option-click twice on Mac), or select the bull's eye cursor right from the top yellow assistant palette: 
Select the upper-right points of the 'windshield'.
Use the Stretch tool (in modeling toolkit) 
 
and grab the two selected points and move them to the left, closer to the center.
Hit enter or swipe away when done.
Now turn the camera to the right with the arrow keys, and extrude, in much the same way as before, two long sticks from the small squares, to make some kind of laser guns.
Oops, we forgot we need some wings too. Turn a little more and extrude the wings from the long narrow surfaces on the side. In the following example, I did two extrusion clicks, not just one. A first one with just the horizontal axis enabled, and another one moving freely in both axis to make it a bit smaller.
Or how about using a different tool this time? Instead of clicking the Extrusion tool, let's try the Sweep tool

 
You can start with a swep on both axes
Click, then hit Spacebar to lock into horizontal axis, then click and spacebar again for vertical or both axis. Hit Enter when done. 
 You'll see that there's an opening in red which you can close. You can also toggle the orientation of the swept section with the SPACEBAR. 

You can also in some of these orientations use the +/- keys to increase or decrease the size of the section as it progresses along the sweep.

Here's the one I chose.
It sure would be nice now if we could easily duplicate a mirror copy of this wing to the other side (assuming of course our alien pilots live in a symmetrically minded world too :-)

Amapi let's you easily extract (separate) a shape made of a set of  facets from the current object. You can then duplicate that shape, weld the original back to where it came from, and weld the duplicate copy to the other side.
 

The 'Extract Shape' tool is located in the Modeling menu: 
and because this is such a valuable tool, I like to assign a keyboard shortcut to it: Go to the
Edit > Shortcuts...
menu and select the Miscellaneous tools option in the menu that appears in the popup window. Find the icon associated with 'Extract shape' and click it, then hit any key, like the letter 'e' (for extract), and you've just created a keyboard shortcut to that tool. Swipe away or click the 'close window' icon (X) in the upper right of the shortcuts editor.
Now let's use a view which is somewhat top-down looking, so we have a clear shot at the wing, and in particular at the part that separates the body from the wing. Use the 'Shape Extract' tool and throw the lasso around the facets and vertices we want to identify for separation.
Hit Enter. No need to move the shape away, but you'll see a bunch of axes which  indicate that you could certainly do that right there if you wanted to separate *AND* move the shape away.

Just swipe the tool away or hit ENTER to complete the separation. You now have two parts, one is the wing, the other is the body. The whole thing before the separation was a volume (closed solid), but because of the separation, they're now two surface objects with an opening hole where they connect. If we want to mirror the wing to the other side and then connect it to that other side of the body, we should make an opening there on that other side of the body too. We could use the Delete Faces tool for this. 
 

Actually, I'll use another method, just for fun. Let's in fact apply a little bit horizontal shift to the separated wing.
After the separation is done, select the wing (click it), then use the Move  tool  and hit the spacebar so it moves only along one axis, sideways away from the ship's body.
You can now see that there is an opening between the body and the wing, and that there is in fact a hole where the two got separated. (hit ENTER to render and see the opening)


Mirroring the Wing

Now, click to select the wing, and  use the 3DMirror tool in the assembly toolkit.

 
Click the right mouse button to specify the mirror reference point. (on Mac: option click). This reference point appears as an 'X' and should be in the middle of the spacecraft's body. 

Hold the SHIFT key down and you'll see the cursor snap to points and midpoints on existing line segments. Select a midpoint on a segment of the body which spans across the left and right half of the body, and thus is on the mirror plane.

Then click the right side of the bounding cube showing around the wing. This causes the 3D mirror to be reflected off that side and placed at a distance which is twice the distance from that side to the reference point. The second wing thus lands exactly in the right place, at the right distance and the right orientation.
Now, select the body, and use the Delete-Faces tool to open up the side where the new wing will have to be attached.
At this point we can easily snap the wings back to the body, using the Snap tool. Click a Wing, click the snap tool, click a point on the wing which is by the opening, and click the corresponding point on the body. This of course will work well when  the two opposing sections are perfectly identical. But what if they're slightly different?
Another option is to actually fill the gap that's between the opening on the body and the matching opening on a wing. Use the Ruled surface tool for that: 
Click the Ruled surface tool, then click a first point along the opening on a wing, then click the facing matching point on the opening of  the body.

Amapi will fill the gap between the two openings. (but it is still a separate filler part which will need to be welded to the wing and body later)

Repeat the process with the other wing: click the Ruled Surface tool, then  click a point along the opening perimeter of the wing, then click the corresponding point on the opening perimeter of the spaceship's body. Another filler is produced.
Now there are multiple parts that all need to be welded together. Use the Weld tool  and throw the lasso to select all parts.



After welding all these surfaces together, we should have a perfectly closed volume. Hit Enter to see it rendered.

Using a bit more imagination, we can add some more detail, such as stabilizers (ailerons), and add more details here or there. You can select the points at the end of each wing to make it more narrow there with the Stretch tool or Scale tool, or drag the end of the wings to the back, add some  guns, etc.
 


Basic render

Clean cartoon style with 2 shades

a metallic look with reflection

If you have a Gif animator tool, you can also assemble a sequence of renderings into an animated GIF, like I did here:

Also, there are several smoothing methods which Amapi offers, and you can easily turn this ship into an organic looking creature. Add some backdrops, spot lights which cast shadows, a planet backdrop or clouds... here are some ideas and sample renderings made in Amapi.

Click the images below for larger images.




What next?....
 

Once you've created the geometry, you can use Amapi to do some basic rendering or animation right there. However, for something more sophisticated, save the geometry in a 3D format and pass it to a more powerful rendering and animation tool which offers lens flare effects, atmospheric effects, motion blur, particles and other advanced rendering features. Carrara (www.eovia.com) is a good tool for exactly that.



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