Originally posted by LFShade
[B]Y-up as an option sounds like a fine compromise to me;)I think Max has been used in enough high-profile FX shots to qualify as a capable FX package, so if it’s not understood to be as such then there’s a lot of misconception out there!
RH
p.s.: Y-up is only illogical in a Cartesian context, not a cinematic context. The camera doesn’t often point straight down at the ground; the camera plane’s Y is usually “up” in the world. If Z-up were so overarchingly logical, it surely wouldn’t have been ignored by almost every 3D animation software on the market. Comments? [/B]
Sure :o)
We are talking about WORLD COORDINATE SYSTEM here, not camera coordinates. The world for a human has North-South, East-West and a VERY important vertical axis (called Zenith, with Z!) which is parallel to the gravity. In human perception, this axis has the highest priority, caused by our life on Earth. Your own local vertical axis is usually aligned to the world vertical axis (except when sleeping or making love, well, at least mostly).
This makes your own local viewing direction very variable relatively to the world directions, but rather fixed to the vertical.
Floorplans in XY were the basis of 2D graphics, with elevations adding a 3rd, Z axis to them. You can imagine that we are not talking about User Coordinate Systems here, but of WCS where X is East and Y is North . So this is an almost ABSOLUTE coordinate system defining a fixed ortiantation, at least on planet Earth.
On the other hand, the Camera has its own XY plane (the projection plane) with -Z running out of it in the depth. The first rendering packages looked at the world ONLY through a camera , making the XY plane of the projection rather important. Usually, by default they looked from south to north into a small fixed “room” like a TV studio, and completely ignorred the world paradigm with its N-S, E-W and up-down directions. After a couple of years, these programs started transferring the camera paradigm to the whole “virtual world” of the application, forcing the World Coordinate System to assume the illogical Y as up, although the local Z axis of the camera is highly variable relatively to the Z axis of the world, except in the rare occasion of looking straight to the North along the -Z axis!
So I would say the Y-up is very subjective and “ego-centric”, while the Z-up is more general and “looking at the world from above”, thus divine, concept ;o)
Obviously, a cinematic context assumes everything around us is just props (created in the Matrix?), and that Star Wars is being made mainly in large indoor studios.
“Our” concept comes from recreating worlds, and when a package makes its money mainly in the architectural and visualization industry, with just few of us fighting in the movie trenches, I can see it being the more real-world oriented and thus more logical for most people out there.
Of course, once you get used to a certain POV like Y-up or Z-up, (or certain religion, music or political party), you start believing it is the way to go for everybody. (and from there it’s a very small step to violence and wars :o)
That’s why I am for the freedom of choice and the pain being moved to the programmers who should do some matrix transformations internally!
Last but not least, there is the myth about some Yost Group members watching a Star Trek episode where Kirk mentioned an enemy ship hiding in a nebula to be having a relative position in Z and then actually appearing above Enterprise! But this is just insider humour… :o)
Bobo, you really know how to make an irrefutable point:D
RH
eh, maybe I`m stupid so dont understand…
what is discussion here ?
is it OK that max has view coord sys as default and force you to understand Y as up ? well that Y up stuff in max is just temporare transformation which is in fact written as Z up in “real”, it is Y only while you perform it and after that it becomes Z, so all ppl who have habit to use Y as up will feel cmfrtbl, maybe not knowing that what they did was actually Z “action…
how, then, describe modifiers and their performing based on axes ?
if you draw box in top, or front, taper will behave differently, it will look objects local coords, choosing Z with same parameters will make same objects but differently oriented, or you suggest that it should make diff objects with same absolute deformation ( like world modifier )
so IMHO it is very simple, who wants to have Zup allways, there is world coordsys, and who wants to feel like in comp app, there is view csys…
Originally posted by gusar
eh, maybe I`m stupid so dont understand…
what is discussion here ?
It is a cultural problem we are discussing here.
Maya and Lightwave users have the words “Y is Up” engraved in their brains. When coming to max, they ask “Y is Y not up? My understanding of the world is shattered!”. We usually answer: “Welcome to the Real World, Neo” and explain what I posted above: They are living in a fake Matrix made in Hollywood and their personal view is hiding from them the fact that in reality Z has always been up… :o)
Have you seen the original question? The guy asked if he has to model differently because Y goes in the wrong direction! It is like an European driving a car in the UK… Everything is at the wrong side, and something inside tells him that it is the wrong side…
The problem comes when swapping data between packages, as you have to transform all vertices to switch the axes, otherwise the meshes would end up turned to the side. (try exporting from max to VRML and reimporting without turning the coordinates back to max system and you will see…) So the practical problem is that max, while sticking to the orthodox Z-up paradigms of the CAD world is probably the more logical world, it is an isle in the sea of Y-up packages that have troubles sharing data with it…
he, now got it…
since I only know max, really had no idea about this axis issue…
but basic geometry tells that z is up, you know horizontal/frontal/lateral plane…if I would open maya and see that y is up, would be suprised, and wondered where was I wrong…
that`s probably from 2d apps with z along your view, and you described it excellent as egotheoism…
…and for exporting, now see why some models dloaded from net are rotated 90 degs:shrug: