Question about Absolute Dimensions

I’m just starting out with Blender and I’m thoroughly hooked on it. I’d like to start getting serious even whilst I’m learning tutorials, and possibly start modeling objects that I can use permanently in future animations. With this in mind I’d like to ask if there is any advantage to starting out with some sort of absolute ‘scale’.

For example, if I model a house, a main character, and a small fairy, I’d like for all of these objects to be the correct sizes relative to each other.

Is there any advantage in creating these objects using some sort of absolute units so I know what their relative sizes will be? I realize that things can be scaled up and down arbitrarily, but I’m still wondering if there is any advantage to modeling objects using standard units to begin with, and if so, how do I go about setting that up?

Thanks

With blender 2.49b it is not possible, eg. the most people work with 1 Blender Unit is one meter.
In 2.57b you could set dimensions to metric or imperial in the scene settings in the properties .panel.
With the default settings the standard cube is two meters wide, like in 2.49b two Blender Units.

Cheers, mib

There is no inherent advantage to creating things in relative scale, and in fact it can be quite the opposite when working with very small things. As long as things are in the correct scale at the time of render, you should be fine.

I suppose it’s good practice to have a certain scale for things; say you created a house and wanted to add it to another scene…

may not seem a lot of bother, but it helps keep you organised…

You’ve brought up a pet peeve of mine.
One blender unit = one meter.
Everyone should now go to the chalkboard and write this one hundered times, “One blendre unit = one meter”
If you download animatable charaters that people have made you find that the sizes are all different. One charater is 5 meters tall and another is 20 meters tall. They don’t play well together like that. Complex armatures don’t always resize well because of the constraints.

Also, if you are going to do any simulations the default for gravity is in blender units (meters), -9.81 blender units (meters) per sec.

If everyone would adopt this as a standard, sharing stuff like rigs would be much easier.

Or you could do what I do because I don’t use Metric and just
say 1BU= 1 Foot or 12 inches.
Then just press N key and set Scale to 1.0 and Subdivisions to 8
and your all set set model stuff down to 1 / 32th of an inch or even
a 64th if you so choose to. If you had to convert over to Metric then
I think you just have to turn it on in Blender and it will be correct.

BTW here is the Standard Conversion Chart.

Measurement Chart

===================================

Inch

1 = 1.0

===================================

Eighths

1/8 = 0.125
1/4 = 0.250
3/8 = 0.375
1/2 = 0.500
5/8 = 0.625
3/4 = 0.750
7/8 = 0.875

===================================

Sixteenths

1/16 = 0.0625
3/16 = 0.1875
5/16 = 0.3125
7/16 = 0.4375
9/16 = 0.5625
11/16 = 0.6875
13/16 = 0.8125
15/16 = 0.9375

===================================

Thirty seconds

1/32 = 0.03125
3/32 = 0.09375
5/32 = 0.15625
7/32 = 0.21875
9/32 = 0.28125
11/32 = 0.34375
13/32 = 0.40625
15/32 = 0.46875
17/32 = 0.53125
19/32 = 0.59375
21/32 = 0.65625
23/32 = 0.71875
25/32 = 0.78125
27/32 = 0.84375
29/32 = 0.90625
31/32 = 0.96875

===================================

Sixth forth

1/64 = 0.015625
3/64 = 0.046875
5/64 = 0.078125
7/64 = 0.109375
9/64 = 0.140625
11/64 =0.171875

Well, I seem to be getting a lot of different answers here from it doesn’t matter at all, to one blender unit should equal one meter, or maybe one foot. That’s quite a huge difference right there. A meter is closer to a yard than it is to a foot.

Having spent my life in the sciences I have no problem working in meters. But I can work in feet too. It doesn’t matter to me. I just like to keep things consistent. I can create my own arbitrary “ruler” and just gauge everything I do to that for my own personal work. But I thought it would be nice to start out working in some “Industry Standard” if there is such a thing.

I tend to agree with aljo above. Things sometimes get bent out of shape if they are scaled to extremes. I don’t know if that’s true for Blender, but I used to do a lot of design work in AutoCad, and things worked best there if they are scales appropriately. I used to run into problems there too if complex 3D drawings need to be scaled to extremes.

I’ve been watching several modeling tutorials for creating characters in Blender. I’ve noticed that everyone I’ve worked with thus far has pretty much just started off arbitrarily. Some people start with the default cube using that as the basis of the pelvis. Based on that alone that would make the default cube approximately about a cubic foot. So I guess that’s a pretty good place to start if I’m going to create a ruler. I’ll just make up my own ruler to be about as long as the default cube and call that a foot. I’ll just make an actual ruler out of the default cube and use that ruler to measure everything.

I’m not worried about being overly precise. I’d just like to know that if I make one character 5 feet 4 inches tall, and another one 6’ 2" tall. They’ll actually preserve that perspective. And if I build a house with 7 or 8 foot tall doors all my characters will work out well with my house.

So I guess I’ll just make up my own arbitrary “foot” based on the Blender default cube. If I took that to be a cubit meter that would be 3 times bigger. Which would be ok by me. I really don’t care. But it seems to me that there should be an industry standard to at least get things in the ball park.

Maybe it doesn’t matter with Blender,. but I do know like aljo mentioned that when things start getting really complicated having to scale them to extremes can potentially introduce problems. At least it used to be that way with AutoCad. I don’t know about Blender.

I’d hate to devote a year to developing some characters only to discover that they are totally out of scale in terms of some industry standard.

@Abracadabra

Others may have a better reason than I do for meassuring they way they do. But give this a try.
Add a mesh (cube or something.)
Go into edit mode, open up the properties panel (N), and open up the Mesh Display panel.
Under the Numeric section select Edge Length (or one of the other options.)
Now select your mesh.
Check it out, the edge lengths are displayed for you. How handy is that?
Now go to the Scene panel in the properties window and in the Units panel select Metric… Then try Imperial… Notice how the messurements on the cube change. Go back into object mode and look at the dimensions in the property panel. Yup, they display in meters or imperical units.
So my question is, with all this functionality that blender is providing for us, why would anyone what to use any other messurement system besides 1 blender unit = 1 meter?

real new to blender but been around 3D sence 1998.
metrick seems to work better then 1/16 .0625 1/8 .125 on PC’s for me anyways.
scales maters to lights ,
learned this one buy using several defrent apps .
default scene load a cube.
not way bigger or way smaller then the defaullt cube.

Metric is the preffered way for me, and it’s always best to work with real-world scales - it saves a lot of headaches when mixing objects from different files. There is an imperial units option for those who prefer it anyway.

One thing to note though - during modelling i usually have models scaled way up, since this gives you more floating point precision, and the viewport camera’s clipping distance doesn’t need to be readjusted. I rescale to proper metric scale only after i’m done with the modelling.

I see it now. You’re absolutely right.

The default cube is 2 meters on an edge or 8 cubic meters total volume. And if you switch to imperial units it actually calls them out as 2.197 yds. It also changes the background grid to square feet instead of square meters.

So this is great! I can go back and forth between metric and imperial units and it’s just a matter of how they are being displayed on the screen. Now I can set the height of my background images for modeling and know that my models will be precisely the height I want, and it’s all done to the correct standards.

Thanks!

It’s nice to have this squared away before I get started.

When I choose “Imperial” in the units section of the scene panel it displays things as “yards”. And displays the word “yards” in the upper left corner of the 3D display.

Is there any way to change that to feet? I tried looking in the User Preferences but I couldn’t find anything there.

Just curious if this can be done, and where that can be changed.

Ok, I found the answer to my own question about how to convert the display to feet here:

http://www.katsbits.com/tutorials/blender/blender-2.5-metric-imperial-units.php

That page is interesting but blender doesn’t use Spacing it uses Scale. And I have tried to change The Imperial to work properly but the smallest you can go is 1" (one inch). Bottom line is it don’t work correctly so your best bet is to use Metric.

Like I said, my method is to not use it and set the Scale to 1.0 and Divisions to 8 that way if you
wanted to model something that is 7 " inches and 5/16th of an inch you can move a vertex to 7.434 for example.

Hopefully they will fix it so it works like that and we can easily switch back and forth with out any problems.