What are the xyz rotation angles for rendering ISO objects?

[Neyjour]

Thanks Korash, but...I don't really think that's going to help for what I want to do. Or, I'm just not understanding it...

What I want to do is render various objects, and I need to know the rotation values for x, y and z. Or maybe it's not even possible to to do it like this, and objects can only be done right if they're drawn?

I've been testing out different pieces and every one seems to have different values to look right (by eye) on the grid. Some are a bit similar, but others are very different. Especially the bridge, which took forever to position...and it still doesn't look quite right to me.

For example, the bridge values are:
xRotate = 28
yRotate = 35
zRotate = 10

And the vine-covered column values are:
xRotate = 33
yRotate = 39
zRotate = 7

The numbers are fairly close for those two, but when I try to match them up exactly, either one object or the other looks really wrong.

And then there's the altar, which has these values:
xRotate = 30
yRotate = 10
zRotate = 10

It's looking like the xRotate is the one that's supposed to be consistently at 30? But not knowing what the others are supposed to be just throws everything off....

Ugh...this is giving me a headache.