IFC to Grasshopper

Replies to This Discussion

Permalink Reply by Jon Mirtschin on March 28, 2014 at 2:30pm

Hi Kristoffer,

Thanks for the post.  Most of the demand is Grasshopper to Revit (or other BIM software) for downstream documentation, scheduling etc.

But I have developed some functionality for importing (and some modifying) of IFC files in Grasshopper.

I've attached a sample script.  Note, the quality of the IFC export will have a big effect on speed etc.  Particularly using IFC2x3 (not really any other software implemented the great improvements in IFC4 yet) really uses "faceted brep" shape representations and this can cause parts such as light fixtures (image from sample revit project) to bloat the file (meshing this object).  Even items such as hand railings are typically meshed.

You might want to use the "export by view" option for the IFC export, and filter out objects such as this if you're not going to use in Grasshopper.

I am also working on an IFC exporter to get more compact and efficient IFC files out of Revit (using advanced breps similar to Rhino) and hopefully there is soon something for users to start testing.

Hope it helps, look forward to hearing suggestions and requests.

Cheers,

Jon

Attachments:

• 140328 decompose IFC.gh, 12 KB

Permalink Reply by Damon on June 30, 2014 at 11:19am

Hi, Jon.

You sent me a sample definition awhile back to read properties of AC curtain panels from a Revit IFC export. Thank you very much!

And here I've found a good sample for using the Decompose components. I'm trying to automate rebuilding a Revit model in Rhino as a single-surface model. For this, I'd like to grab the exterior face of each wall, for example.

What I'm finding is that using IFC Wall > Deconstruct Brep gives three Breps: top, bottom, and sides. This final "sides" Brep can be baked and exploded, but I'd like to be able manipulate each face separately. 

Any way to do this? I'd have the same request with roofs, floors, etc. (does IFC Roof exist as a component?).

Thanks,
Damon

Permalink Reply by Kristoffer Negendahl on April 2, 2014 at 2:13am

Hi Jon. 

Thank you for replying. 

I am working on different large scale projects simulating various building performances (energy, daylight, indoor environment, etc.) and at the moment my main source of building data is delivered in IFC2x3 (standard-exported from Revit 2013/2014). The files are often bloated and full of proxies as well as inconsistent object/class information. I am trying to figure out how to handle these kinds of files and automate calculations in a more rational way.

My current workflow consists of the following steps

Revit>>Simplebim>>GG-Rhino>>Grasshopper>>BPS>>Grasshopper

This is far from optimal. Since I have little control of the actual Revit-export, I have trouble getting to the source of the data. I use Simplebim to filter and adjust the IFC-model and create consistency. The files are still +50mb after filtering various bloated and unnecessary data away and my experience is that GG-grasshopper are struggling when reading large files. As a consequence I read the file directly with the Rhino-reader which creates a layered structure in Rhino. Then Grasshopper is used to reference geometry into various building performance simulation tools (BPS).

This method removes any relevant non-geometric data stored in IFC and "dumb downs" the model as dependencies and relations are lost.

What I need is a much simpler workflow that requires no changes when importing IFC. It is great to hear you are working on the Revit-export-side. I am aware that the Revit-export is not exactly creating super-high quality IFC-files and this may solve many of the problems I am having.

Ideally I like to load any IFC-data containing envelope-geometry/information and room/zone-geometry/information into Grasshopper. Use Grasshopper to modify and argument the data. Make simulations then feedback the results in some form and store it on object-level in IFC-format.

The last part seem to be achievable with GG, but the current load process stops me from getting there.

A "tiny" proposal for ggIFC importing in Grasshopper:

If I may suggest a future improvement of the ggIFC-load process in Grasshopper, it would be great to have a "ggIFC Load by type" function. If it is possible the function would run through the step-file finding any "wall" or "window" or "column" or whatever type is called, then parse it as a branched list with information of geometry object and class-data and various identifiers. My hope is that large files can be partially loaded directly through GG and would let the user extract whatever data needed. And hopefully still allow some of my RAM unhurt in the process. My concern is that partially loaded files will not easily allow the user to reconstruct the IFC-file as it were. Unless every little bit of information is included. But maybe after "load by type" is used on e.g. walls and the user for example adjusts the color of some walls, their unique identifiers can be used to "ggIFC Find and Replace" object color data in the original IFC!?

Anyways thank you for providing a great tool. I know this is a lot to ask, but I'm sure you see the value in my "tiny" proposal.

Best Regards 

Kristoffer

   

 

 

Permalink Reply by Carlo Beltracchi on June 30, 2016 at 12:22pm

Hi guys, 

nice to hear that someone's doing the same work I'm trying to do. I recently wrote to Jon about working with GG to import IFC data from Revit to Grasshopper, manage them and then reimport to Revit.

Is there actually any improvement in this workflow?

My alternative option (still not tested) is to export data to GH via dynamo with flux, manage it and then export to Revit...

Is it possible to share knowledge about this kind of workflows into this discussion?

For example with sample files or personal experiences?

Thank you so much

Permalink Reply by Sandi Sirikhanchai on December 6, 2016 at 6:16pm

Hey everyone,

You guys doing exactly what I am trying to do. I am helping with a research project that is aiming to export a Revit model into Grasshopper and then use Honeybee and Ladybug plugins. I have not been able to get a Revit into grasshopper using an IFC file format.

I have downloaded files uploaded by Jon on the following blog and assigned my IFC file but there are no outputs, everything is just null.

https://geometrygym.blogspot.com.au/2010/12/bim-importing-ifc-to-gr...

I would like to follow on from Carlo, and re-ask the same question:

"Is it possible to share knowledge about this kind of workflows into this discussion?"

Thank you,

Sandi