2010-02-04

Neo-Volumetrics

Sweet!

You can do volumetric analysis without LightWave or any other expensive modeler now. Google Sketchup has had a lot of Star Wars models made for it. And, with a volume plugin found here, you can get far better estimates of a ship's volume than you can by simply guessing at simpler shapes.

For instance, a TOS Connie I downloaded and tried to rescale by hand (I think it's about 850ft right now, which is only 259 meters) came out to 156,000 cubic meters, which is not too bad considering. If I calculate after the fact to try to correct it (bearing in mind I've never used the program so I don't know what I'm doing when measuring), I come up with 216,000 cubic meters. My ST-v-SW Connie volume is 211,000, so that's pretty damn close all things considered.

Models I've tried so far:

TOS Enterprise with bad length
http://sketchup.google.com/3dwarehouse/details?mid=c6fbcd07ca96c97ed217db332f4745ff&prevstart=0

Gorgeous Munificent, but only 733m long (had to lengthen it)
http://sketchup.google.com/3dwarehouse/details?mid=9ad48f8c225108697417f80cc0f3cf2c&prevstart=0

Venator (bad length, had to lengthen to 3725ft)
http://sketchup.google.com/3dwarehouse/details?mid=99aa1f34d852fbb5ff2c56fe607e6796&prevstart=0

Invisible Hand (awful length)
http://sketchup.google.com/3dwarehouse/details?mid=768aca096055b122a64762cc420ce77a&prevstart=0

The very pretty Munificent model I measured to within 5% gave me a volume of 2,137,120 cubic meters. A simple Venator model at the same accuracy nets me 10,616,929 cubic meters . . . a difference of almost five times, despite the ships being only 1130 vs. 830 meters (the Muni's shorter). (For reference, the Muni's volume is less than a Sovereign Class Federation starship, and she's 130 meters longer . . . we all know how sleek and spindly the Sovereigns are.)

Given that much of the Venator volume is composed of carrier-related space, though, she's really a big empty ship. If we assume half of her volume is dedicated to fighters, then the ship's only about 2.5 times the volume of the Muni, which (in concert with life support and other humanoid crew requirements) gets us closer to understanding the combat ratio from TCW.

The Invisible Hand, at only 1088m, comes out to a length-corrected volume value of 6,436,107m^3.

Other models:

AT-AT:
http://sketchup.google.com/3dwarehouse/details?mid=1a451e8ef0305f6ec4e5bc34eca27821&prevstart=0
615 cubic meters at 22.5m height (or thereabout).  Seems about right compared to Danube Class at 542 cubic meters.

Pretty good Falcon:
http://sketchup.google.com/3dwarehouse/details?mid=4ebf7bc43d767bd425405c61741b95bb&ct=mdsa&prevstart=0
But something's wrong with it . . . even with the length corrected, it only reads ~700 cubic meters, which is very wrong.  Even a 30m wide 2m tall saucer should have twice that.  The Falcon should be at least 1500m^3 and probably double or so.

ISD with excessive docking bay:
http://sketchup.google.com/3dwarehouse/details?mid=f9efd56c3137d14ba4ee0fb6a51564c3&prevstart=0
There's another ISD with excessive reactor bulb and unshapely docking bay.  Can't seem to find a really good one.
Edit:  Ah, here's one:
http://sketchup.google.com/3dwarehouse/details?mid=b656e4ab907a876b213ef50647c3c88&prevstart=12
But when I make it a mile long, I get a volume of 86,547,000 cubic meters, which is way high.  I tried doing the volume in cubic feet, since the template for the model is in feet, but it came out the same.  So something's wrong with the model, I think.
http://sketchup.google.com/3dwarehouse/details?mid=ec3479e79c61cf1ef33214a2991e934f
Tried this one, too, but ended up with 18.7 million something whatever, which is also crap.

Dammit, Star Wars fans, can't we build a model that doesn't suck!

Executor:
http://sketchup.google.com/3dwarehouse/details?mid=21053701a00c82de630a81e41b3b6ffd&prevstart=0
The volume comes out wrong (10% of expectation based on what I had already), but the ship is of approximately the correct dimensions.

Romulan Warbird:
http://sketchup.google.com/3dwarehouse/details?mid=c5b88c16e0091eed6208ceb8c2299bcc&ct=mdsa&prevstart=0
Scaled to 1358m, I got a volume of 18,389,163 cubic meters, which is probably much closer than the 26 million that came from a really crappy looking Lightwave model back in the day.

Runabout:
http://sketchup.google.com/3dwarehouse/details?mid=d421c83927baa74e264c43f47c3e0e4d&prevstart=0
The length is bad.

Enjoy!

3 comments:

Author said...

This Acclamator model gives a volume of 13,574,251 cubic meters when expanded out to the appropriate dimensions.

That's a bit much, I believe. For one thing, the ship's rim seems thick. However, even with a 20% reduction, that's still awfully close to a Venator. I'm wondering if perhaps the Venator and Acclamator aren't as far apart as I was thinking.

http://sketchup.google.com/3dwarehouse/details?mid=7eedbeaa5216ff06ccd600f441988364

Author said...

Great DS9 model . . . it's even scaled more or less correctly, out of the box!

http://sketchup.google.com/3dwarehouse/details?mid=10e3882c71567f28bdbd60b756975f5d

At 1468 meters, this model reads 97,810,507 cubic meters.

Holy schneikes. Not sure how I feel about that figure. I don't think that's right . . . but then I suppose it could be.

The station model is 56m thick at the outer docking ring. If we assume that all of the station's material could be squished into a cylinder of 1450m diameter by 15m height, which seems more or less right by eyeball estimation, then we'd wind up with a figure of 24,779,464 cubic meters. That's pretty close to the existing value I had for the station at 1250 meters with a model whose reliability I don't recall. But nonetheless, I feel safer with a 20-30 million cubic meter value than one over three times larger.

I really need to learn how to use this SketchUp stuff so I can figure out what's wrong with these models in the context of using the Volume plug-in.

Author said...

I did just the central core (not even the habitat ring) and got 5,596,000 cubic meters, which by eyeball isn't too bad, specially for a station 1468 meters wide as per this model. I was thinking it ought to about match a Galaxy, and that's ridiculously close. I'll keep looking.