Blender's "resolution"?

Hi, this is a question that has popped into my mind recently as I’ve been considering Blender as a serious tool to use in my trade(Architecture), for which I need to work with precise measures(to the centimeter, most of the times, but precision nonetheless). Thing is, I read something in the few “architecturally” oriented tutorials I’ve followed that Blender only has input up to the third decimal position… i.e. 0.00X(not sure if I’m explaining it right, my technical English not being that good). Yet when I move, it displays the differential up to four decimal places, and if I input a number with more precision I notice some sort of scientific notation pops up (N.NNNe+000…).
Further still, I’ve noticed that after I input those extra micro BU’s, if I go into the transform properties, it displays only the first 3 decimal places, even when I click on the number box. Yet if I get off the number box again(formally “re-inputing” the number it already displays), I notice a small change in position… Indicating that the objects location did have more precision than it was displayed, yet it is lost when I re-input the number with less precision.
So, what is the real precision of Blender? Up to how many fractions of a BU? When I Grab, am I moving the objects with that precision, with the fourth decimal places precision, with less precision? Why do the number boxes on the transform properties(and the Array modifier) allow for less precision than there actually is?

To whom it may concern :slight_smile:
I know that the problem is easily solvable by assuming a BU is equivalent to a small unit, maybe the smaller you intend to use, but sometimes it is easier to think in certain larger units to me. Also, when I use big units my camera gets a bit awkward, but that’s subject for another post.


Good questions, I’ve been wondering about that recently, too. For example, if I’m working with 1BU=1Metre and I move an object .654 Blender Units, has it moved 654mm, or 65cm
(losing/rounding out the 4mm)?

Blender seems to be very precise. Perhaps this isn’t accurate enough of an answer to the question, but:

Fire up Blender. Zoom in all the way to one edge of the default cube, and see how small of a value you could move it and have Blender register a change. I noticed the cube move when I translated it 0.000001 units in the positive X direction. Scaling had a similar effect: Blender scaled the cube to a factor of 1.000001. It should be noted that though the 3d viewport registered the change, the numerical input at the bottom of the window didn’t register that last decimal place. When 1.0000001 was used as the scale factor, no change seemed to occur.

Conclusion: Numerical displays display less exact information than the actual 3d information seems to contain. Scaling and movement was effective at 6 decimal places in the 3d window and only at 5 in the numerical display at the bottom of the window.

…but I may well be wrong :slight_smile:

On a different note, take the default plane and scale it up to 30 times its normal size. Make sure you’re in orthographic mode, and zoom all the way in on one corner of the cube. You can see a little bit of perspective - orthographic mode isn’t perfectly orthographic.