In the previous post of this series, A engine of the cargo space ship, I've shown how I made a single engine of the cargo ship. That model of ship has four of those engines. Their are attached to the central body of the ship through the mean of tubes. This central body is mainly the cargo bay, but on top of it there's the “cockpit”. The cockpit is half a sphere on the standard cargo bay.

The hardest part was the engine. Now we can put all the remaining things together and we've the basic cargo ship.

Here it is while it is traveling not so far from a red star.

(Credit for the star field: Paul Bourke)

The code

We have the EngineSection from the previous already cited post; we need just to make an union between four engine sections, the standard cargo bay (a central cylinder) which holds the four engines through cylinders, and finally the cockpit, our half sphere. Here's the code

union {
  // 4 engines and the cylinders which keep them unite
  union {
      object { EngineSection rotate y*180 translate y*4}
      object { EngineSection rotate y*180 translate -y*4}
      object { EngineSection rotate y*180 translate z*4}
      object { EngineSection rotate y*180 translate -z*4}
      cylinder { 1*y, 4*y, .3  }
      cylinder { -1*y, -4*y, .3 }
      cylinder { 1*z, 4*z, .3 }
      cylinder { -1*z, -4*z, .3 }
      translate x*-.5
  }
  // the standard cargo bay
  cylinder { -.5*x, x*2, 1
             translate -1.98*x 
  }
  // cockpit
  sphere { 0, 1 }
}

I've removed every textures (not important here). Also notice that the cockpit is drawn as a complete sphere; this is because half of it disappears inside the cylinder of the standard cargo bay, so it's not necessary to “cut” it.

Now our ship can fly

Let's see our ship beginning a maneuver to leave the orbit around the red star.