Yup or Zup ?

DaveC · Post by **DaveC** » Wed Oct 31, 2007 7:36 am

I use Zup. Blender. Even though i think of x as across, y as up and z as depth. I'm used to it enough in blender for it to not matter.

Silverman · Post by **Silverman** » Wed Oct 31, 2007 12:33 pm

Since I use Blender it is set to Zup, but I prefer Yup. I started with POV-Ray 15 years ago and to me that will always be the correct orientation. Z should be coming toward you, not up. When you graph something on paper Y is up, X is left-right, so Z should be coming off the paper toward you, not up. Z is the depth dimension. Blender's use of Zup still confuses me.

Zom-B · Post by **Zom-B** » Wed Oct 31, 2007 9:53 pm

after googling a bit, it seems that in mathematical point of view Z is up

It simply seems that a 2d x-y graph is generally always lying on the ground,
and you see it from above...

nowadays we don't write with a stick in the sand on the ground, but have ultra portable and movable paper and a monitor, so by moving our medium by 90° its now the question it the graph stays or get new defined!

The Z-up crew moved user view by 90° and letting the graph as it is on the ground, like it was all the time before, if you turn your view, the earth stays where it is too!

The Y-up guys & gals moved view and graph to 90°... like they where the center of the world

CTZn · Post by **CTZn** » Wed Oct 31, 2007 11:26 pm

We french say: you don't argue about tastes and colors. You learned one or the other. Yes the mathematical up axis is Z, but my maths teachers always used x and y in the blackboard, and obviously Y was up wether I was facing the blackboard or my paper. Well, as I said arguing is vain

Dogs or cats ?

Kram1032 · Post by **Kram1032** » Wed Oct 31, 2007 11:53 pm

My teacher did that, too, but as I said, all the others, including me, did the same on a flat top-viewed paper, where z is up

oh, and in 3D-geometry, y is the diagonal axis that shows the perspective

(Y-buffer ^^)

WytRaven · Post by **WytRaven** » Thu Nov 01, 2007 12:01 am

cats obviously...duh!

Kram1032 · Post by **Kram1032** » Thu Nov 01, 2007 12:05 am

I'd say mouses

Silverman · Post by **Silverman** » Thu Nov 01, 2007 1:49 am

Kram1032 wrote:I'd say mouses

Dogs!

Silverman · Post by **Silverman** » Thu Nov 01, 2007 2:10 am

ZomB wrote:after googling a bit, it seems that in mathematical point of view Z is up
It simply seems that a 2d x-y graph is generally always lying on the ground,
and you see it from above...

The Y-up guys & gals moved view and graph to 90°... like they where the center of the world

That was how I figured out the different 3D views. The Z up assumes you are on a planet. Z is one of the radials extending from the center of the mass. The center of the Universe in that coordinate system is somewhere below you. Zup also has the observer looking at the x-y plane at an arbitrary angle, rather than straight on.

Yup is free of that restriction. The center of the Universe is the origin point in your XYZ space. You are looking straight onto the x-y plane.

Mathematicians have adopted Zup, but probably because it became standard hundreds of years ago. It isn't necessarily better or more logical.
Engineers use Yup.

Kram1032 · Post by **Kram1032** » Thu Nov 01, 2007 2:33 am

Silverman wrote:The Z up assumes you are on a planet. Z is one of the radials extending from the center of the mass. The center of the Universe in that coordinate system is somewhere below you. Zup also has the observer looking at the x-y plane at an arbitrary angle, rather than straight on.

Yup is free of that restriction. The center of the Universe is the origin point in your XYZ space. You are looking straight onto the x-y plane.

??????????????

CTZn · Post by **CTZn** » Thu Nov 01, 2007 3:27 am

Dogs stink and you have to bring them where they need to go

Y or Z, this is all virtual, but zup users are wrong

kidding.

Ok so we have more zup users than yup here... I was not expecting that ^^

Kram1032 · Post by **Kram1032** » Thu Nov 01, 2007 3:30 am

I'm not sure, but I think, most part of indigo users use blender as their main modelling app...
there, Z is up, which directly leads to these results... (could be entirely wrong, though)

CTZn · Post by **CTZn** » Thu Nov 01, 2007 3:52 am

That for sure is not entirely wrong, Mark !

Kram1032 · Post by **Kram1032** » Thu Nov 01, 2007 4:09 am

You could expand that poll, but I don't think, that'll give results, you'd want:

1) My main app is Yup only
2) -||- Zup -||-
3) ... can switch between...
4) I use more than one app, all are Z ...
5) ...Y up
6) ... can switch
7) ... some are Y up, some Z

... some can switch, some are Y up
9) - || - Z up
10 (extreme case) ) some can switch, some are Y up some are Z up

and then, "In case of switchable, which is standard and which is your setting?"

as two more polls...

and finally "which app are you using?"

Way too complicated, I guess^^

CTZn · Post by **CTZn** » Thu Nov 01, 2007 5:03 am

Yup or Zup ?

In your main 3d application, the up axis is set to:

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