Why are blocks allowed to be scaled?

I’m curious, because correct me if I’m wrong, but this doesn’t exist elsewhere in the CAD world.

If you scale something up in Solidworks, Catia or NX, you have to do it on the body level (ie, in Rhino terms, only inside the BlockEdit).

Similarly, neither STEP or IGES are aware of any scaling (example: create 4 block instances, and scale 1 of them uniformly, and 1 non-uniformly, export and re-import… and you’ll see that you end up with 3 block definitions instead of 1).

Where does this come from?

Why is this allowed (especially non-uniform scaling)? Is there any real-world scenario where this is useful?


Suppose I have a block representing a tree.
Scattering some of those trees on a patch of garden and being able to scale them somewhat randomly will allow for a single tree definition yet with the appearance of many different size individuals

Similar for placing gemstones with varying sizes on a ring.

Scaling a beam with a certain profile in the lengt direction only, allows for the same profile block to represent different lengths in the assembly.


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Scaling is useful for me too, but it should be possible to use the blockedit of the embed block. I expect that in edit mode the unscaled version is editable.

@Pascal Often I thought about this and I forget to post it only. Could it be possible to edit nonuniform scaled blocks in place please?

Hi Micha - I imagine this is hard. Would you expect to be editing a version that reverts to some uniform scale during the edit, or the non-uniformly scaled version?


I would expect that the original version without any scaling is opened during editing. That would be good enough.

The original block is somewhere in the file data saved and it’s frustrating not be able to edit the block anymore. It would be a great help to get success to the block again.

Well, that can be done now by inserting a new copy of the block with no transforms. Hardly an improvement…

This has been discussed a lot before, including roughly a year ago. I still believe the best solution is to allow users to edit, with a warning some geometry may get wonky. But there tons of cases where all will be fine, including all when we just need to change in-block objectss properties…

Is this also possible for embed blocks too? In the past I run in the situation that I tried to edit a block and got the message, it’s not possible, since it is non-uniform scaled. But I didn’t scaled it, maybe by a mistake. Is there a way to get an original block within the Rhino session?

AFAIK embeded blocks yes, but linked blocks will always open a new Rhino session to edit.

I mean, if in my scene is one embedded block and this one is non-uniform scaled, how can I insert a copy of the original block for block editing?

Hi Micha - the Insert command will place a new instance.


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It is also useful when designing multi-cavity thermoform molds where not all cavities (molding the same shape) have the same orientation.

AutoCAD has always supported scaling of blocks. It’s one of it’s most useful features.