topic Re: Ugly Breps in Parametric design

Ugly Breps

Czaja — Thu, 11 May 2023 09:07:10 GMT

I was happy when I discovered that in the last connection update Brep extraction was finally added. But why are they so ugly and useless?

I wonder why this is made like this.

Is this just a strange looking mesh translated into polysurface? I can't even merge the face.

It is possible to export this geometry in a more or less useful form in conventional way (save Archicad file as 3dm) but it's faaar from parametric approach.

Any info about when it could be solved? Keep it up devs, I think many people would like to see a good GH-Archicad connection. But IMO it can't be done halfway, either it's solid or it's a game for users of overcoming plugin's limitations - frankly a few have time and will to play it.

Re: Ugly Breps

leceta — Sun, 03 Feb 2019 15:47:37 GMT

+1 !

Re: Ugly Breps

Laszlo Nagy — Sat, 09 Feb 2019 17:37:57 GMT

I think currently the Grasshopper-ARCHICAD Connection does not transfer element geometry resulting from Priority Based Connections, such as the stepped Wall skins at corners or stepped skins resulting from an intersection of a Wall and a Slab.
These are transferred to Grasshopper as extrusions as far as I can see. I guess the feature just has not been fully developed yet. However, cuts resulting from Solid Element Operations and Trimming to Roofs/Shells do get transferred, so we are getting there.
That being said, I fully support you request.

By the way, I just found that yes, the BREP is triangulated for some reason. I don't know if it is a Grasshopper thing or a GH-AC Connection thing. However, I found you can solve this by connecting the "BREP" or any of the "Surface" outputs of ARCHICAD Deconstruct Nodes into a Grasshopper "Mesh" Node, and it will result in a non-triangulated Mesh Surface. Please note that if the Grasshopper-ARCHICAD Connection is installed, Grasshopper will have 3 Mesh Nodes. You will need the native Grasshopper Mesh Node for this.
Or, you could use the "Mesh Brep" Node, which will approximate a BREP with a Mesh geometry, and you can define several parameters for this approximation.