Vertices move fractionally by themselves?!?!

[Anonymous]

I'm using 3DS Max 2014 and I've been a 3DS user for about 9 years but this is the first time I've encountered this problem.

It seems that 3DS moves verticies very slightly without me even telling it to.  Say for example I copy and paste the coordinates from one set of vertices into the coordinates of another, it will move the vertices as expected but then when I tab out of the spinner boxes the vertices will move fractionally.

It's REALLY getting on my nerves because, even though it's only a small difference, I still notice it and I have to keep fixing it.  I'm also a bit of a perfectionist when it comes to creating things so it's really grinding on my nerves.

What could possibly be causing this issue?

I haven't tried to re-create the problem in an earlier version of 3DS yet but I guess that's my next step.

[Steve_Curley]

Most common causes of anything like that are a) inappropriate System Units for the size of the scene and b) the distance from the Origin of the objects (or sub-objects) in question. Check those first, and remember that Max (as it uses single precision floating point maths) really doesn't like very large or very small (many decimal place) numbers and will become increasingly inaccurate the larger (or smaller) the numbers become.

[Anonymous]

Perhaps my units are too small... I'm working in meters because the games engine I'm working with works with that.  I guess I'll have to build larger scale then scale it down =/

[Steve_Curley]

Which game engine (if you don't mind me asking)? A base unit of a Metre seems very big to me - I (vaguely, it's been a long time) recall that a single unit in UT2K4 was equivalent to 1.905cm (work that one out if you can ;)). At least it gave realistically sized objects ingame. A unit of a Metre will make modelling small objects (distances) very difficult to do accurately in Max.