New models and their scale

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Lamoot
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Joined: 22 Apr 2016, 12:03

New models and their scale

Post by Lamoot » 22 Apr 2016, 12:22

Hello,

First of all, great work on OpenMW engine and editor, I'm really excited about the possibilities it offers and how I can play original Morrowind on it. 8-)

Recently I started getting models from Blender to OpenMW CS via OSG native format. I'm at a point of figuring out the relation between Blender Units (BU) and object scale in Morrowind. I found out that a height of 130 BU roughly equals a standard humanoid in-game.

Image

This can be translated as 130BU = 2m in-game, which is an odd scale to work with. Perhaps I'm wrong in assuming the guard is 2m tall. Regardless, it would be very useful to have a standardized scale to work with, so that 1BU = 1m. The scale factor could be applied at exporting, thought Blender's OSG exporter doesn't support such an option.

I'd like to hear other people's thoughts on this and whether anybody knows where Morrowind's object scale comes from.

ezze
Posts: 426
Joined: 21 Nov 2013, 13:20

Re: New models and their scale

Post by ezze » 22 Apr 2016, 13:50

This is a great idea. But we need more information to make a reasonable conversion between BU and meters.

For example, if the guard is 2m tall then how tall is the candle holder? how large is the treasure box?
Considering guards are probably fairly large humans I'd expect about 1.9m. However, it means we got the even worse 19/13 conversion ratio :shock:

fragonard
Posts: 7
Joined: 09 Jun 2012, 21:49

Re: New models and their scale

Post by fragonard » 22 Apr 2016, 13:55

Could have been foot/inch based originally. 130 units of 0.5" would make the human 5'5" tall, short by modern standards but normal in the middle ages.

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GreyFox
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Joined: 16 Apr 2016, 22:41

Re: New models and their scale

Post by GreyFox » 22 Apr 2016, 13:58

Oblivion uses a coordinate system with units which, like in Morrowind, are 21.3 'units' to a foot, or 7 units to 10 centimeters (or to put it another way 64 units per yard [~70 units per metre]). Internally the game converts from game units to centimeters by multiplying game units by 0.1428767293691635
http://cs.elderscrolls.com/index.php?ti ... vion_Units

MithrilLeaf
Posts: 33
Joined: 25 May 2014, 19:53

Re: New models and their scale

Post by MithrilLeaf » 22 Apr 2016, 14:00

The generally accepted height of a male Imperial is 5'9" or 175 Centimeters. That gives us roughly an increase of 35% over the blender units to get to centimeters in Morrowind. Less than ideal, but fairly workable.

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Pherim
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Re: New models and their scale

Post by Pherim » 22 Apr 2016, 15:42

First, average NPC height (scale 1.0) is 128 units, not 130. Second, this does not equal 2 meters (or where do you live that the average human is 2 meters tall? :D ) but approximately six feet which is about 182cm. The most accurate conversion I know of is 7 units to 10 centimeters, as was already quoted by GreyFox, so 70 units would be exactly 1 meter, or close enough to make no difference.

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scrawl
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Re: New models and their scale

Post by scrawl » 22 Apr 2016, 15:50

The "in X feet radius" magical effects use a conversion factor of 1 foot = 22 game units. (I don't know if it's documented somewhere, but that's what I got experimentally with the telekinesis effect).

1 foot is 12 inches, 30.48 centimeters.

So, we can conclude that:

1 unit = 1/22.0 feet = 1.385 cm

height of imperial male = 128 units = 177.34 cm

Seems close enough.

Edit: funny, 177 cm is exactly what you get when you google "average male height". :D

Lamoot
Posts: 69
Joined: 22 Apr 2016, 12:03

Re: New models and their scale

Post by Lamoot » 22 Apr 2016, 15:58

Thank you for all the informative replies, it's very helpful in understanding what's going on.

According to Oblivion's scale page, an average person of scale 1.0 has 6 feet, which is around 182cm, as Pherim mentions. So if we agree that the guard is 6 feet tall and seeing he roughly fits a 130 units tall object (a close relative of the 128 one ;) ), the 140 tall object is then our 2m.

Image

The tallest object was originally 2 BU units tall and then scaled by a factor of 70.
It's possible then to model everything in Blender, where 1 BU = 1m if you scale by 70 before exporting.
This means 1 Blender unit directly translates to 1 OpenMW unit, when using the OSG exporter.

Does this make sense and can we define the ratio for all future props this way, as a guideline for OpenMW Example Suite?

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Pherim
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Re: New models and their scale

Post by Pherim » 22 Apr 2016, 19:48

Yes, Imperials have a scale of 1.0, so this would be quite accurate. And yes, if 70 units are 1m, then naturally 140 are 2 meters. ;)
scrawl wrote:The "in X feet radius" magical effects use a conversion factor of 1 foot = 22 game units. (I don't know if it's documented somewhere, but that's what I got experimentally with the telekinesis effect).
Yes, this is also mentioned on the page GreyFox linked to. But in practice this doesn't seem to make much of a difference. With a 7units/10cm ratio, 1 foot would be 21.3 units.

Lamoot
Posts: 69
Joined: 22 Apr 2016, 12:03

Re: New models and their scale

Post by Lamoot » 22 Apr 2016, 21:41

Cool, it makes sense to someone else as well :)

For various props it isn't that much of an issue of having an exact scale, even when it benefits the workflow (no trial and error when trying to achieve a specific size). For modular environment parts it's more important so that various tiles fit together once the go through the export process.

Anyway, here's a result of proper scaling for the example suite.
Image

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