Axes in blender

The interface, modeling, 3d editing tools, import/export, feature requests, etc

Moderators: jesterKing, stiv

nemesis
Posts: 10
Joined: Thu Oct 24, 2002 10:26 pm

Axes in blender

Post by nemesis »

I don't know about you guys, but I think the axes in blender are screwed up, in blender, x is lengh, z is height, and y is depth. In most 3d graphics programs, x is lengh, y is height, and z is depth. Shouldn't it be like this in blender too? Is there a reason why it isn't?

Dani
Posts: 143
Joined: Fri Oct 18, 2002 8:35 pm

Post by Dani »

In imagine 4, the axes are the same as in blender.
I doesn't bother me so much, but it can be a bit bothering when exporting.
Is it worth changing?
With a version having that change, old blender files will load with a 90° rotation around x, no? (since the axis are reversed...)

Dani

Zsolt
Posts: 4
Joined: Thu Oct 17, 2002 9:39 pm

Post by Zsolt »

Actually, I like the Blender axes-system the best.

I always think of the coordinate system so that the x and y axes (or is it axii?) are on the ground, so x is width and y is length, and then z is the 3rd extra dimension: height. This is sort of the way the world works: you move about in the two dimensions along the ground (x and y), and the extra z-axis points up. This is a better approximation of reality IMHO than having the y axis pointing up, and the third z-axis pointing forward.

Besides, it's Blender's coordinate system that is right-handed. Some people (mathematicians, for example :) would have nightmares using the non-regular left-handed one.

Zsolt

nemesis
Posts: 10
Joined: Thu Oct 24, 2002 10:26 pm

Post by nemesis »

I agree with what you said about the real world axes, but I just thought it would be better that mathematics and CG programs are all the same. It's no biggie though, but for new people using blender that have previously used other CG programs, it might be a bit confusing at first.

ajk48n
Posts: 1
Joined: Sun Oct 27, 2002 12:10 am

Post by ajk48n »

It's probably fine to leave it how it is now, since it is not necessary in order to get Blender compiling right after download, but I think the best possible way would be to have an option in the program so you can choose whether you want the world to be Z-up or Y-up.

malkere
Posts: 5
Joined: Wed Oct 16, 2002 5:26 pm

Post by malkere »

Plus don't forget, the axes shift depending on which view you're working on.

Jedimaster9508
Posts: 5
Joined: Wed Nov 13, 2002 2:05 am

Post by Jedimaster9508 »

I think the axes (¿or axii? :?: ) should be left the way they are. In most geometry books (aahh!! math!! :wink: ) the axes are the same as in blender. :)

WedgeBob
Posts: 0
Joined: Sun Feb 06, 2011 10:35 pm
Location: Cleveland, OH, USA

Post by WedgeBob »

Right, I was wondering about this, because some recent game engines (here's looking at you, Unity), uses the Y-Up axis in most of its imports of .FBX exports, and since I am also a 3D Buzz member, this is important to know, since I'm probably going to have a lot of unpredictable results if I model in the way that Blender does, when it comes to exporting and importing into Unity.

preacher_mg
Posts: 0
Joined: Thu Mar 23, 2006 8:42 am

Re: Axes in blender

Post by preacher_mg »

nemesis wrote: In most 3d graphics programs, x is length, y is height, and z is depth.
Perhaps most but not all: In 3ds Max, the axes are arranged just like Blender's. Same goes for Autocad I believe. And Autodesk is a Big, Big player in the field. They might decide to enforce this system on the rest of their acquired products.

muddyal
Posts: 0
Joined: Sat Feb 05, 2011 6:03 pm

Math Axes

Post by muddyal »

Math axes are not like Blender which is what bothered me right away after all we start with 2D on x,y in plane geometry etc. and then add z when working in three dimensions. I wonder what the history of Blenders axes is?

preacher_mg
Posts: 0
Joined: Thu Mar 23, 2006 8:42 am

Re: Math Axes

Post by preacher_mg »

muddyal wrote:Math axes are not like Blender which is what bothered me right away after all we start with 2D on x,y in plane geometry etc. and then add z when working in three dimensions. I wonder what the history of Blenders axes is?
If it's anything like 3ds Max, the rationale is that for architectural uses you begin with a 2D ground plan on the X-Y plane and then add height. If you create environments - buildings, terrain, level maps - it makes perfect sense. If you create vehicles or characters, less so.

stiv
Posts: 0
Joined: Tue Aug 05, 2003 7:58 am
Location: 45N 86W

Post by stiv »

Z as height is common in math, science, engineering, mapping and similar real-world applications. Z as depth only makes sense for screen oriented applications.

You will notice that Blender uses Z as height for the global coordinate space while the local Camera coordinate space (a screen view) uses Z as depth.

RiViT
Posts: 0
Joined: Mon Apr 25, 2011 2:05 pm
Location: Ottawa, Ontario, Canada

Post by RiViT »

I'm not really new to Blender; I've looked at it several times over the years. That said, I am new to this forum, so please forgive my temerity for just jumping right into a discussion, but I think I have something of use to add...

Any form of thinking that helps someone understand what's going on is useful and usable for that person, but after learning and working with one system, it takes a lot of effort to adapt to another.

Anyone coming straight into the creation of 3D graphics, without passing through 2D, will feel right at home no matter which way the axes are oriented, Z up, Y up or even (and I likely shouldn't even mention this for fear someone will implement it) X up.

I don't think the axis feeling awkward has anything to do with math or architecture or science. I believe it has to do with computer graphics in an historical context.

Originally computers did 2D graphics. X was left-right, Y was up-down. The natural extension of that into three dimensions is to have Z go in-out.

Can you imagine using PhotoShop and thinking in X/Z instead of X/Y? I think that would feel strange, too... even unintuitive.

Since there are supporters in both camps (and quite a few if discussions around the Internet are anything to go by) how about we convince the Blender developers to toss yet another option into the preferences window: Switch Z/Y

Then everyone would be happy (including me).

Anyway, that's my input on the subject.

[Edited after post for clarity]
-Ron T.

rfrancis
Posts: 0
Joined: Thu Jan 01, 1970 1:00 am
Location: Adelaide, Australia
Contact:

Post by rfrancis »

RiViT wrote: Since there are supporters in both camps (and quite a few if discussions around the Internet are anything to go by) how about we convince the Blender developers to toss yet another option into the preferences window: Switch Z/Y

Then everyone would be happy (including me).
Including me as well!
I look for the option in every release.
DirectX uses a Y-up system for anyone programming with it.

stiv
Posts: 0
Joined: Tue Aug 05, 2003 7:58 am
Location: 45N 86W

Post by stiv »

I look for the option in every release.
The chances of this happening are very small. The issue has been discussed before. The necessary work goes far beyond adding a checkbox to the User Prefs and could best be described as massive. But, as always, patches are welcome.

Post Reply