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I've been having a bit of a problem with making the Y axis my up axis when exporting mesh and scenes from Blender. Both Blender and my export target use right handed transformation matrices. Z is the up axis in Blender while Y is the up axis in my target. The problem exists in 2 places though. The scene's transformations can't just be shifted on the X axis to fix this, because I also need to do the Y/Z switch for the vertices in the mesh (export as vertex.x, vertex.z, vertex.y). I need to have the actual Y and Z rotations switched, so that if the Y and Z rotations are the same, no change will occur (ie. identity). Thanks for your help in advance. Feel free to ask questions if I was not thorough enough.

user387381
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7 Answers7

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Blender does two things different than the rest of the known world! 1. It uses Z axis for vertical (should be Y); Y axis for horizontal (should b X); and X axis for in and out (should b Z).

Very weird! Every high school graph since the beginning of time uses X for horizontal and Y for vertical.

  1. It uses the right mouse button for selections.

U can change the selection btn in Preferences, but not the crazy axis arrangement!

jack kunkel
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no, you do this

y=z
z=-y

no rotation of 90 degrees can make you go from left to right hand.

Federico klez Culloca
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user254885
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I ran into a similar issue when working with cinema4d and blender. In cinema4d Y is the up axis and rotations are heading,pitch and bank.

Blender's system looks like a right handed system, but rotated by 90 degrees on x axis.

I did the same thing for coordinates(exported as vertex.x,vertex.z,vertex.y). For rotations, I think you should add 90 degrees(math.pi * 0.5) for rotations on X axis and the rest should be fine.

HTH

George Profenza
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Have you tried just using Select All (the 'a' key) and then r x 90 to rotate everything 90 degrees around the X axis and the pivot point? (your pivot point is choosable in the menu bar of the 3D view if you need to control that).

You could do that, export, and then undo.

Mutant Bob
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Just Download Wings3D. Export from Blender as .3ds and then Import this file in Wings3D. Now you can just export it from Wings3D, again to .3ds. But instead of clicking directly on .3ds, click on the small icon in the right of the ".3ds" menu. now you can unchecked the Box Swap y und z axis and import the .3ds in another program.

idanshmu
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icetea1999
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There is no way that would be possible. Coordinate system was innately selected as hard coded from the blender source and there are no explicit option has been made in blender to switch it. It would also affected many of the hard coded functionality of any function blender was used or has been made by assume that coordinate

However, in theory, it would be possible to access blender source code and rebuild the blender to have it use another coordinate we would like. Albeit we need to carefully swap everything related to coordinate system

I too wish that left handed coordinate system (as of Unity3D) would be industrial standard and blender should at least have another version that work in left handed coordinate. People should just graduated from table coordinate to screen coordinate already

Thaina Yu
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In blender, you could add empty plain axes, that will correct your orientation when exporting to unity, or try exporting as fbx file and change orientation in export options

Jorge Manuel Bello
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