Inquiring minds ... axis assignment in Simio

[mfranklin]

I have wondered about this and have received this question many-many times from clients: Why did Simio assign the y-axis as the vertical axis? I have yet to find a software package that isn't using xy for the plane and z for vertical. Thoughts?

Sincerely,

Martin

[ccrooks]

When we first implemented it, we went with a standard "First Person Shooter" coordinate system, meaning (for a person standing up, looking forward), X was the horizontal on the screen, Y was vertical on the screen, and Z was depth. Of course, if you change your perspective to now "look down" at the world (which is the standard way you start looking at stuff in Simio), those same axis now turn into X being horizontal, Y being depth, and Z being vertical.

We certainly could maybe rename and reorder them in the property grid or something to make more sense so maybe instead they maybe look like:

Vertical (old X)

Horizontal (old Z)

Height (old Y)

I don't know if that would be more or less confusing for users however.

[mfranklin]

Thanks for feedback, Cory. Vertical and Height will likely cause a lot of confusion.

Would be nice to have it changed to name XYZ the same as all other 3D programs, but making that switch now will break a lot of existing XYZ reference implementations. At least we know the story behind it.

Sincerely,

Martin

[ASagan]

Interesting discussion. Most programs I've worked with uses the same coordinate system as Simio -- confuses me a bit from my physics days because the z direction is reversed, but the xyz used in Simio is 'correct' otherwise.

Unfortunately I don't use these programs enough to say for sure which ones use what...