Maya

general-usage

Preference files never save…argh

Its not in the prefs.

make a file set values to inches, save this file. go to file -> bew optionbox and set the default file to be the file you just saved

done. Read the warning, because theres actually no sane reason to do this.

at its most simple, i just want my units to be inches by default instead of centimeters.

You dont actually want to do this. Maya doesnt respect the values anyhow. Whoever added this preference to maya was fullfilling a mangerial need nothing else. And did bothced job of it.

In fact maya just plain ignores the setting, everything in maya says that the ACTUAL value of the setting is one unit = meter. Irrespectively what the pref says. So in a general sense maya IS unlitless that is one maya uint is UNDEFINED or just a number. Well thets fine since a unit only has any meaning in releation to other units which would require every node/gui to recognize this somehow but they dont so the entire pref is idiotic.*

Warning! Since maya is actually unitless, no node actually respects your unit setting. In fact several nodes go absolutely bonkers if you try to change the setting. Since the setting is for most part totally irrelevant for ANY purpose whatsoever every possible tool that needs to be able to do some ACTUAL unit functionality would need to have a special set it yourself function. But luckily theres no such thing inside a 3d animation studio.

If you dont understand why this is the case you dont understand units.

• there is a reason for this, ad thats the fact how you were taought units in school. You think its fundamental due to the fact that so much time was used to teach this. However it is not its just a conversion figure. Since maya never actually convert units across to other units it doesn't matter, since you have no way of knowing what the unit would be. Which is a boon form a computational point of view,´Ive seen people get tangled in computation because they used light years nanoseconds and millimeters in same computation (and offcourse the sstem dindt do symbolic math so it went totally into rounding hell all of it)

yikes, not happy to see maya shows no respect to the units, though.  strange.

well computers in general do not. Why would they. for them any number is as good as any other number. Its not like the computer need to go and tape measure reality or anything.

Units only actually comes into play if you mix units across your inputs (and in maya you dont), since obviously you cant type 2 m in the channelbox or attribute editor you'd need to convert yourself. Since your doing it why would computer need to care. Theres no such phycial value in your 3d world that would actually be locked undefined, you can change thet value. Since your managing the units you also manage that value according to your own computation.

But yes read my reedit for the above post. This is actually a good thing. As a real system that would account for units would ineed slow down amya considerably. Since it can only be done in 2 ways thet are bad. The other is pure symbolic solver, but that means youd have to carry around lots of symbols and compute with them all the time. Wasting a lot of effort. The other is to convert all data to one unit behind the scenes. This is numerically unstable since you wont know what the unit is. Now this probably almost never happens to cause problems but when it does it is virtually impossible to debug*.

*i fact i worked for a company that developed a tool that did this. Now theese vere engineers who actually made physical stuff. None of the customers who asked for the feature could end up using it because they got problems understanding when the sytem did it wrong. It kept me flabergasted to see how many people with a doctorate in engineering didnt know what a unit IS.

PS: by teh way 3ds MAX, softimage, blender, mudbox and zbrush dont really respect units. The entire approach to visualisation industry has jsut sidestepped the problem since there IS no problem with that.

Yeah but see the problem is that even the way you use fbx format istelf is not really doing you any favors here.

A typical example of this is the collada format .dae thet assumes maya unit is meter even if your pref is set to cm.

we've run into slight annoyances where c4d is set, i guess, to inches....

well dont guess measure. The real value may be supprise to you. As it might be that the entire workflow is botched form the start to end.

The real solution is to adjust the data in transit.

PS just wanted to add, The makers of the fbx format were aware of mayas/other softwares quirky behaviour and when you export to fbx via the export options dialog maya asks WHAT unit your unit in maya should be converted to. Saving this export preset is infinitely better than changing your maya files.

Likewise there should be  conformation statement in the other end when you load in c4d you can also just set that value correct too.