Is there a way to make the scale an actual representation of the measure system (metric) I use?

Question

I don't know why this is made as it is because it's totally not making ANY sense and broken as well. Why is scale a multiplication factor instead of a representation of real world values? [Metric system:] Why is a cube 2 meters at a scale of one? I chose metric and set the unit scale to 0.5 so it would actually be what I enter it to be, but this blender is doing what it wants. First it acts like I want. Doing a cube of 20 x 12 x 1 meter works. Then I save everything open the project up a day later and when I add a second cube of the same size, it's not the same size as the object I created a day before. Even though the settings are still the same (metric and unit scale of 0.5). I can't believe that crap. i mean I understand it in a game engine like unity or unreal engine to be a factor instead of a unit, but not in a 3D modelling tool -.-

what is also not understandable is that when I create a cube of height (z) 4, I actually have to put in 4 into the location z field so it is on top of the grid even though the origin is in it's middle. so actually shouldn't i have to enter for the location just 2...

Is there any way to correct this so scale can actually be set in meters instead of a multiplication factor??? Can't understand that implementation at all, especially annoying when it's not working as it should

Answer 1

If you set up a unit scale for Blender, inputs will parse the strings you enter in any field which expects length.

Supposing you have set the units to meters, and the Unit Scale to .5 (at least, in my build)..

• If you enter '1', Blender will always interpret that as 1 Blender Unit (50cm)
• If you enter '1m' Blender will interpret that as 1 meter
• You can enter '25cm' or '250mm' or '.25m' etc. to refer to that length
• If you enter '1in' Blender will interpret that as 1 inch. Because you have declared your dimensions to be in meters, that will be translated to 2.54cm
• You can even enter an expression like '25m / 4' to get 6.25 meters

I'm open to correction, but it is true that the last-used radius for object creation can not be made to persist in the .blend file, and reverts to 1 of your declared base unit when you reopen it. However, the last creation size requested (in the tool region) does persist within sessions, on a per-primitive basis.

These are deliberate choices on the part of the developers, not careless. There are many choices in Blender that I don't personally agree with, but in the vast majority of cases, if I stop to think about them, I can see the arguments for the choices having been made that way. Usually it's to do with 'cleanliness'.. i.e. consistency between different parts of what is, after all, a large application. I have been pleasantly surprised by that consistency in Blender's way of thinking, compared to many proprietary applications, especially those with a long history of accretions .. :)

Answer 2

The system is not broken in any way and is working as intended and it also makes perfect sense.

Scale is the size of an object compared to itself. If you have a tennis ball of standard size or in other words one that has a scale of one standard tennis ball and you want to redefine its size and make it twice as big, you can enter 2 in all scale fields to get a ball precisely twice the size of a standard tennis ball. Notice that I can participate in this whole situation without having a clue about what the actual dimensions of a standard tennis ball are in centimeters or any other units, because it's irrelevant. Scale property exists only for this purpose - for you to be able to redefine object's size in relation to its original size. It has nothing to do with units or any measurement systems and is intended to be like that. There is nothing wrong with it, the whole concept of scale in Blender(and pretty much in all other 3d applications) is like that.

What you want scale to be is dimensions:

Well - it is not. Dimenstions are a different thing. Only they define the size of an object in relation to a specific measurement unit and unlike scale not in relation to the object's own original size.

If you adjust the scale of an object for it to have the dimensions you want or if you adjust the dimensions of the object this way changing the scale and then decide that this should be the new original scale of this object, you can apply the scale with ctrl+a -> Scale:

I would like to advise to keep an open mind and try to understand how things work first assuming that they are working as intended. Searching for the reason and explanation why things are working the way they are as opposed to getting angry at them for not matching your expectations may be extremely valuable when learning to work with complex 3d software like Blender.