Changing Dimensions, but how to lock?

In my other 3D application, Strata, when I want to change the dimensions of an object, I click a small lock-icon and I only have to change one dimension and the others are automatically adjusted to keep the shape of the object. I just can’t seem to find this in Blender, I see lock symbols with scale/rotation/location but not with dimension!?! If I want to change the hight of my object to say 35cm I type 35cm on the Y-dimension, and the X and Z should follow but how?

If you want the whole scale to change, just select the object, hot key S, and key in the scale value in decimals. If you do this in Object mode, don’t forget to apply scale Ctrl + A.

If I hit S my object changes scale as a whole when I move my mouse, but I cannot type in the dimensions…

If you know you want, say, the height of your object to be 10 meters, type 10m into the z dimension box. Then look at the z scale value and either copy and paste that to the x and y or type it in. Then apply the scale as ridix suggests.

You should be able to, but not in the box, just start typing and look in the status bar that replaces the window header as soon as you start to drag. The numbers you type will appear there.



… if you use a recent build.

Neither of your methods work - Safetyman’s won’t work when the object’s scale isn’t 1, and you might not want to apply it when working with instanced meshes like you often do in architecture. DruBan’s method lets you type in the scale manually, but not the dimensions. If your object size wasn’t exactly 1 unit large before, it won’t give you the desired result.

Uniformly scaling to fit a given dimension is a surprisingly hard thing to do in Blender. You could easily write an addon, but I can’t seem to find a way to do it from the vanilla UI.

Alright, call me stupid. I hit S, then type in 35, my object dimension becomes 70 meters…
How can such a simple task become so hard to do? In Strata I just click a lock… :frowning:

Your object is scaled by 35, so you need to first divide by the current object dimension (which is 2 in your case). Indeed what you describe is not possible as easily right now and requires looking up the dimension.

Having such a lock is a valid UI request, (useful in other areas, such as image aspect ratio locking) maybe I could add it? Will need some discussion with the UI team first.

Edit: started a discussion here: http://lists.blender.org/pipermail/bf-committers/2014-January/042720.html

It would be a good addition to the N panel, PsyFi.

Until then, hit S, then type in your desired size, then a slash, and then your current size. You will have to look it up, but you only have to look it up for one axis, the others will follow. Do the same no matter whether you are scaling up or down. Blender will scale as you type so don’t be alarmed when you type in your first number and it becomes very large, just keep typing. As what you type becomes ‘parsable’ Blender updates the window.

I don’t want to suggest that this method is anything but a workaround for an actual UI element. It shouldn’t be necessary to know algebra to use Blender! On the other hand it has been asked for before so there may be a problem in implementing it.

Druban’s suggested method works just fine.

A method was added for that via dragging across several properties at once, check

Works very well except for the dimensions values. Highlights all but only changes two boxes and only shows one of them in the effect.
Works perfectly when scaling textures and this is a big timesaver!

Thanks for mentionning that, i didn’t noticed in buildbot that it’s now possible to type 25/35 or any other math after pressing a S / R / G , it always annoyed me to have to do the calculation in an external way to get the desired number to use for scale as in current 2.69 and previous when you pressed the / key, Blender changed your 25 into a 1/25 automatically, so typying 25/35 only ended into 1/2535

And after having tried on a recent buildbot, it’s really great !

Can someone confim this (that worked on the buildbot version back in february) does not work anymore in both stable 2.70a and in current buildbot version, and so we’re back to that annoying 1/2535 whenever you type the desired 25/35 during scaling ?

http://i.imgur.com/dlAQNWo.jpg

The only workaround i found is to do this non user friendly way :

  • select the 35cm edge you want to rescale with a precisely 25cm
    http://i.imgur.com/WajMEDL.jpg

  • press S and do not type anything or move the mouse, only press Enter

  • Press F6 and move the mouse there exactly
    http://i.imgur.com/8VcE1qC.jpg

  • now hold Left Click on your mouse and go down like that, until the X , the Y and the Z settings are all becoming darker
    http://i.imgur.com/BYGDv6H.jpg

  • stop holding Left Click , and you’ll then be able to type the desired 25/35
    http://i.imgur.com/R5iQLtn.jpg
    http://i.imgur.com/wPV5wqT.jpg

So you’ll get the wanted exact 25cm
http://i.imgur.com/3vKC7wP.jpg

Can’t understand why they removed the ability to just press S and type 25/35 that they added at some point, now it’s more click to do for the same result …

Yes Sanctuary it’s quite sad but so many people were upset about having the extra functionality that they must have taken it out, although I tried really hard to speak against removing such an useful feature, to the point where I felt I was just trolling… That’s the way it goes sometimes with the lowest common UI approach.

It’s really strange to me that the “lowest common UI approach” is actually to make it harder and more complicated to use with more clicks.
I guess i’ll never fully understand Blender development and will have to keep using workarounds…

I wasn’t aware of this, i just gave a try and it works on the current buildbot, thanks, that will help.

googling that, it looks like it was actually documented, but on the changelog :
http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.70/UI

We have two "modes", simple and advanced ones, use '=' or 'pad*' to enable advanced mode, and 'ctrl-=' or 'ctrl-pad*' to switch back to simple mode. 

But indeed not really intuitive as i can’t see how anyone can guess = is for changing the input method if they have not noticed those few lines in the 2.70 changelog.

edit : oh looks like the method change does not stay , you will need to press = before typing the numbers during a transformation, as once you did the transformation, it silently revert to the original method, so you have to retype = before entering the numerical inputs
I wish it was an actual option you could enable disable in user prefs instead of having to press = everytime.

Sanctuary, you’re overcomplicated things a bit. You have dimension visible in your drawing which means you have N panel opened. Size and scale fields are just a bit up. Ctrl-c on size field value you have, drag across scale fields then type in value you want, slash, Ctrl-v, Enter.
I’m assuming scale was 1 -applied before, that is.

While “=” looks logical as a switch for following complicated expressions user in me don’t get this “1” plus brackets all over :/. And “-” was great time saver…

Can you show me where they are in Edit Mode (not in object mode , i know where they are in Object Mode N-panel) ? Because when i go to N-panel in Edit Mode i sure don’t see the X/Y/Z scales and dimensions in there for a selected edge ?

Did not know about the numpad * thanks!

Well, you gotta roll with the changes or get rolled over with the changes, if you know what I mean. Cheers.