Blender&Archicad - New model instead of updated one

Hello everyone, I’m an architecture student and I’m experimenting with my master thesis the interconnection between softwares, for a more efficient workflow.
First of all: thanks for creating speckle, its an amazing project!

Let’s jump straight to the problem: I’m trying to interconnect grasshopper, archicad, and then blender.
The idea would be to parametrically design the project in grasshopper, send it to archicad to manage all the data, and then send it to blender to use it almost only as render engine.
Everything works fine, except for the last part (I don’t know If I’m missing something or if its a proper bug): when trying to receive the updated project from archicad to blender, instead of updating the geometry, it create a completely new model (no matter if I use “collection instances” or “linked duplicates”; with that, I basically lost all the uv texture mapping, having to correct everything from scratch.

What can I do?
I’m working on mac m1, archicad 27, blender 4.1.1, last (non wip) speckle connectors update.

Thank you in advance!
Giulio

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Hi @GiulioMarsano,

When receiving in Blender, the receive will not remove or edit your existing blender geometry. Instead, it will behave similar to a file import, and create new geometry from the received file.

We do however see the need for us to implment an Update mode like you suggest. It’s something that’s been requested before, but there is several technical challenges for us to overcome before we can offer this.


To clarify your comment on this, I would expect that UV mapping is preserved IF there were no changes to the receiving object.
i.e.

  1. You receive Archicad model in Blender
  2. UV unwrap a wall
  3. Send a new Version from Archicad, with some objects changed (not the wall)
  4. Re-receive the new version, UVs should not have been removed unless the wall was changed in Archicad.

If this is not the case, then please can you share with me the Archicad file and links to the Speckle models so I can investigate the problem here. This would help us identify any bugs and/or help us design a better solution for future.

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Hi @Jedd , first off thank you for the super fast reply!

My bad, by looking at this old video I thought the sync functioning of the element was the same as explained (Rhino geometry to blender).
So only the modified elements were recognised and updated.
In this video as well (revit into blender) its demonstrated how updating does not generate new geometries, and replace the element modified inside revit. That element is the only one that needs the UVs to be set again.

What happens to me is not what I would expect from your explanation:

  1. Receive my archicad model in blender
  2. UV unwrap walls and stairs
  3. Send a new version from archicad with JUST the stairs changed (moved in a different position)
  4. Re-receive the new version: what I receive is a full new version of the whole model, no matter if I modified something or not.

This is what makes me think I did not yet fully understand how does it work.
If I get it, the proper way should be (after point 4):

  • delete all the elements of the new collection that already does exist and were not modified
  • replace in the old collection (with UVs) the modified elements with those maintained in the new collection.

If so, its better than nothing, but not exactly what I was expecting based on the linked video!

Let me now if I did not get it, and my files are necessary!
Hope I was clear, thank you for your time and for the amazing project!

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