Real world units (cm, mm) instead of generic ones [Proposal]

[chiboreache]

would be really helpful

[satabol]

Very convenient. https://docs.blender.org/api/current/bpy.props.html#bpy.props.FloatProperty (param [unit='Length'] ) but need be append into every length/size property.

[Durman]

Implement this is problematic.

We have two ways to store socket properties:

• Store property in a node. In this case we can control property options per node class and per socket. But reading such property is quite inefficient. It takes O(len(tree.nodes)). Though reading property is only needed when it's changed and only one property usually can be changed simultaneously.
• Store property in a socket. In this case options of a property are shared between all nodes and all sockets of the same type. So it's impossible to add the length option only to some nodes and some sockets.

There is poorly documented feature - Property manager which can change some option of properties but as far as I know it neither works with node system nor it has the unit option.

[chiboreache]

@Durman when job have to be done in certain way - there is no question for efficiency - you will do it in any case (btw you can always buy 5950X with 64Gb of RAM)

so my point - there is should be the choice.

[rendetto]

If such a feature adds performance overhead it must have the option to be switched off. I'd always prefer performance before convenience :)

Isn't it easier to just add a calibration (scale) node before export, matching the target units?

Just my two cents :)

[Durman]

(btw you can always buy 5950X with 64Gb of RAM)

Are you seriously think that everyone can always do this? 😄

Though O(n) is not so bad performance, I did not mention that it's becoming worse with displaying first type of properties. To display them it takes $O(len(tree.nodes)^2)$. So it can be a problem just to display a node tree. And computer characteristics won't make great difference.

Also it's not simple to replace socket property types. As far as I can see we have to create new version for every node which properties should be replaced, for backward compatibility.

[satabol]

I try a view of another control:

It is not convenient to change units on fly. If a user expect mm and you will change it to another units this may be embarrassed.