# Metric Scaling and Editing

Hi community,

i just recently started using Blender and have run into a problem that i hope won’t be one in the end.

Coming from Lightwave i am used to the fact that i can model/edit my meshes with absolute metric measures. If i wanted to move a point exactly 4mm on the y-axis then i could do just that.
If i measured a realworld object beforehand i could use these exact measures in Lightwave and
recreate the object easily.

I just don’t get how to approach this workflow in Blender.
Let’s take the simple task of recreating a box of cigarettes which is 8.5cm/5.4cm/2cm.

First I switched to metric in my scene settings, added a cube in object mode and scaled it
accordingly using the “dimensions” settings.
This seems to be the worst way of doing things since it messes up the uv-unwrapping and won’t work for more complex models at all.

So i’m switching to the editing mode, where the metric system seems to be completely absent and i can only work with relative numbers. Every scale operation starts of with the base value of 1. So in this case i went ahead, chose z-axis as my orientation point and calculated the relative proportions.
If z = 1 (8.5cm) then x must be 0.635 (5.4cm) and y must be 0.235 (2cm). Hell yeah, my proportions are right and I can even uv-unwrap the mesh correctly, good!

But honestly, this can’t be it right? What if i wanted to move a vertex up by 5mm now? Do i have to
take out my calculator again?

In the end i want to import the models into unity keeping the scale 1:1.

Any help would be appreciated, i think it’s just me misunderstanding the concept here.

Greetings,

Philipp

Let’s take the simple task of recreating a box of cigarettes which is 8.5cm/5.4cm/2cm.

First I switched to metric in my scene settings, added a cube in object mode and scaled it
accordingly using the “dimensions” settings.
This seems to be the worst way of doing things since it messes up the uv-unwrapping and won’t work for more complex models at all.
Add a cube and type in the desired dimensions in the dimensions boxes. This will change the object scale but at any time you can clear then back to 1 with Ctrl+A/scale

Like i already said, doing it this way messes up my uv map (gives me only squares even if i have scaled to rectangular in object mode).
Furthermore i still don’t know how to properly work with absolute metric units in edit mode.

If you did what I said, if you scale a cube in object mode and then unwrap you wouldn’t get squares, you’ll get correctly proportioned rectangles.

But honestly, this can’t be it right? What if i wanted to move a vertex up by 5mm now? Do i have to
G Z then type the distance you want to move it along the z axis

So i’m switching to the editing mode, where the metric system seems to be completely absent and i can only work with relative numbers. Every scale operation starts of with the base value of 1. So in this case i went ahead, chose z-axis as my orientation point and calculated the relative proportions.
If z = 1 (8.5cm) then x must be 0.635 (5.4cm) and y must be 0.235 (2cm). Hell yeah, my proportions are right and I can even uv-unwrap the mesh correctly, good!
I’ve got no idea why you’re going through this rigmarole

Maybe I’m confused, but if scaling a cube distorts the UV mapping of your object, I don’t understand why you wouldn’t switch to the 3D viewport, and correct the mapping?

Your initial post suggests to me that you may be using a workflow that the developers have not previously anticipated. If scaling the cube distorts the UV mapping, then you’ve added the mapping before completing the mesh. My experience suggests that the developers of Blender anticipated that the mesh would be completed (at least to a certain point), and then the material and texture would be mapped to the scaled mesh.