Because, uh… we here in the 3D world like a little bit of pain.
I haven’t done CAD/3D modeling in years. I hate this chart. Great chart, thanks for sharing.
Great chart, thanks for sharing this.
Arbitrary and historical reasons.
A good overview about why and who: https://ahmetburul.medium.com/coordinate-systems-of-3d-applications-guide-ddfa2194ed88
Personally, I’m super annoyed that Z is not up. but that’s just me coming from Blender and Unreal. It makes programming 3D games more annoying, imo
Edit to add: With Godot having its origins in 2D, Z is “into the screen”. and that orientation basically stuck. Why they used negative, I’m not sure
I think especially in 2d, using the negative direction makes sense, as things that are “higher” should occlude things that are “lower”. It’s the same in HTML/CSS.
Why not? You mean instead of the opposite? There’s two “common” coordinate systems with opposing Z.
https://en.wikipedia.org/wiki/Cartesian_coordinate_system#Orientation_and_handedness
Well, it causes moving forward to be on the negative Z-axis instead of the positive, which isn’t intuitive.
Also, when we’re looking at the front of our model in the editor, the positive Z-axis faces away from us and the positive X-axis is on the left. Kinda backwards.
Maybe there’s something I’m missing, but that’s the point of this thread.
Not if you think of forward as “towards you.” It comes from Math. X is right, Y is up, and then when doing 3D, Z is out of the page, bc that’s easiest to draw.
I haven’t used Godot, but from the info you gave, it seems like they started as a 2D game engine.
For something started as 3D, I would expect x and y to be on the floor and +z to be against gravity.
Well, in 2D, one would expect x and y to map to camera up/down and camera left/right in some way, depending on where we decide the origin goes on the screen. In the game world, gravity might be +/- y; it’s kind of irrelevant. In any case, z has to map to the axis the camera is looking down.
But IIRC you can just apply a global transformation and use any coordinate system you like.
