Can't retrieve user properties from geometry inside a block

Grasshopper Human
1

It doesn’t seem possible to retrieve user properties from geometry inside a block.

Can%20not%20Retrieve%20user%20properties%20inside%20a%20block
Can%20not%20Retrieve%20user%20properties%20inside%20a%20block1616×618 184 KB

2

Is it because you are passing data through the text panel? Not a good idea!

3

Hi Joseph,

That’s not very smart of me indeed, but unfortunately, the problem is there :

Can%20not%20Retrieve%20user%20properties%20inside%20a%20block-Corrected
Can%20not%20Retrieve%20user%20properties%20inside%20a%20block-Corrected1491×670 190 KB

4

Hmmm… In the bottom example, you are connecting a brep to the ‘A’ input, while in the top, you are passing it attributes (‘att’) instead of a brep (‘geo’)?

5

This components accepts either geometry or attributes.
In fact, the geometry output by the “BlockExplodeRecursively” component seems to be devoid of attributes…

Geometry%20loses%20attributes
Geometry loses attributes.jpg1670×907 124 KB

6

I tried to assign the “user text” key and value directly to the block instance, but it’s the same problem : the “udk” and “udv” outputs have nothing to say, unless I plug the "Object attributes " directly to the “Dynamic Geometry Pipeline” :

User%20data%20at%20last
User%20data%20at%20last1542×648 196 KB

The problem is that this leaves with a very limited use of User data from blocks in Grasshopper…
In fact, we only use nested blocks, and the most important attributes are on low-level blocks.

7

I think I found a workaround : Elefront seems to retain the properties from the geometry inside the blocks and the “GetUserAttributes” component manages to output the Keys and values.

Elefront%20Deconstruct%20Block
Elefront Deconstruct Block.jpg1975×719 149 KB

8

A couple notes:

  • The geometry output by any component will not work with the object attributes component - this can accept either an Object Attributes object itself, a Rhino.DocObjects.X type (like a raw block from Dynamic Pipeline) or a referenced rhino object - (it will say “Referenced Brep”, for instance). Raw geometry in Grasshopper contains no attributes. This is why the Block explode components also pass out attributes (the “att” parameter).
  • You appear to be correct that user data keys + values are somehow stripped from the objects in the “Explode” process; I will investigate this.
9

This turns out to be a Rhino bug - the InstanceObject.Explode() method strips user strings from attributes objects. By querying the instance definition instead of relying on explode I can fix this in my own code.

10

Thanks Andrew !

11

reported the bug here: InstanceObject.Explode strips user text from object attributes

here’s a hotfix for Human in rhino 6:
Human.gha (416 KB)

12

Any way to update the code to use the same type of Blocks that elefront brings in to GH?