Convert block to brep

Is it possible to create a solid/polysurface/mesh based on a block in either rhino or grasshopper? Since a block can consist of multiple items i want to know if it is possible to create one item(brep) with the exact same shape as the block. I have been thinking about using “shrinkwrap”, however i wonder if there is a better way.

You can use the Explode Object component in the Rhino tab to retrieve the geometries from inside a block.

yes, however when i try to join the exploded block i end up with a combination of meshes and surfaces that i cant join in to one brep

Then you’ll have to filter surfaces / polysurfaces and meshes. Convert the meshes into polysurfaces and then union everything. Depending on your requirements, shrinkwrap might be easier.

Thank you very much for your answer. I have tried using shrink wrap, but it seems to make the calculations go very slow. Your suggestion of converting meshes to polysurfaces seems smart. is there a simple way to filter out the meshes? Is using dispatch an alternative for instance?

Please post a Rhino file with some geometry.

Some of your objects are meshes, others are surfaces. Assuming these are windows, the frames are a mix of meshes and surfaces.

What is the source of such a :poop: file?

Is this file converted from *.ifc or Archicad?

On the screenshot below, you can see a part of a frame. This is an open mesh. The missing faces are saved as two separate surfaces. Really? :rofl:

It is converted from .ifc. I believe the ifc originates from Archicad.

Hehe it is a :poop: file indeed, however that is what i have to work with unfortunately. That is the reason for me wondering if there was a quick way to create a brep from a block(of :poop:).

Any suggestions besides using shrinkwrap?

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I’m in the same situation every now and then.

What is the goal? What are you planning on doing with the geometry?

i want to evaluate the surface area (preferably as length x width). This can of course be done in the ifc. this is just so that i can limit my workflow to just rhino/gh

The main objective is to evaluate the shading of the windows (left, right and top) by measuring the distance to the shading object and the depth of the shading object.

I think Shrinkwrap is the least painful way.

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Hei Maar -
That geometry looks somewhat like what Sofie posted - Outline of mesh (shadow)
… and since it looks like you’re both located in the same town, I suppose this might be related.

I had started looking into Sofie’s case using the new-in-Rhino-8 Grasshopper components for dealing with blocks. I’m running into an issue - or multiple issues that I’ll try to find time for to check further. Those issues are specific to blocks being defined with a w0 origin and the actual geometry being quite some distance away from that and / or block instances being scaled by 100. In your case, the block’s base points are on the objects, and there’s only the issue of scaling…

Generally, something like this might work…

Working with block instances in a Rhino (15.4 KB)


ok. Thank you:) Any suggestions for settings to use? i am not very familiar with shrink wrap (12.1 KB)

I’d start with an edge length of 0.5 centimeters.

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