Elements getting mixed up converting from Brep to HB_Zones

[loicw]

Hi everyone!
I am pretty new to Grasshopper and honeybee, so I guess my question just comes from a lack of experience.

I am trying to import Geometry from Revit and to turn it to Honeybee Zones. To practice I am using the simple example file provided by Revit (“rac_basic_simple_project”).
I import the geometry from Revit to Rhino, using Grasshopper. To do so I do as shown in the video of rhino.inside Revit: https://www.rhino3d.com/inside/revit/beta/guides/revit-to-rhino
The geometry is greatly imported, wall are seen as walls, windows as windows etc.

Then to convert this geometry into HB_Zones, I follow the video by Chris Mackey :
2 - Honeybee Energy Modeling- HB Zones from Masses Part1: Mass2Zones

I use the Brep component to set multiple Breps, selecting all the geometry that is now in Rhino.

However, out of the HB_zones component, when I show the preview of the Walls, it shows all the model, not just the walls. And the previews for the roof, windows, etc don’t show anything.
It seems that the elements get mixed up during the conversion from geometry to HB_Zones.

Is there something that I am doing wrong? Is there a better way to convert Revit geometry into HB_Zones?

Thank you very much for your help.
Best.
Loïc

[loicw]

Another issue is that the closed Breps are surfaces and not zones as they should be as in Chris Mackey’s video.
This way to convert Revit geometry into HB_zones might not be the right one, or I am missing some steps.

[Erikbeeren]

Hi @loicw

For honeybee/energyplus you will need the space/zone geometry. You can try to export the gbXML from Revit and hope the generated geometry is correct. Mostly it is not! So the best way is to rebuild the model in grasshopper/rhino using the examples you can find on the forum.

[loicw]

Hi @Erikbeeren,

Thank you for your answer.
gbXML is definitely not convincing, it never works great, and the bigger or more complex the projects get the less it works.

Do we know why is there so much effort put in Rhino-Grasshopper and the Revit-dynamo part is much less developed? There are so many projects done using Revit nowadays than full compatibility with the energy calculation software would make a lot of sense.

Re-drawing the entire geometry in Rhino can’t be part of an efficient workflow from a Revit model to energy analysis…

Thank you for your time!
Best !

[wim]

Hi Loïc -

@loicw

Do we know why is there so much effort put in Rhino-Grasshopper and the Revit-dynamo part is much less developed?

See these answers:

Ladybug dynamo nodes giving error on Revit 2020

This issue is happening because the Dynamo changes its installation folder in every couple of releases. At the same time there is no easy way to access this data from the API. We had to guess what will happen next which was not really efficient. I have opened an issue about this in 2016. I will consider updating our nodes and try to fix it once the Dynamo team resolves this issue. You may want to go and comment on the issue or vote it up so they consider it sooner than later. PS: I understa…

Phasing out Ladybug Tools Dynamo Packages in favor of using RhinoInside Revit

Thank you for your comments. RhinoInside will need a Rhino license. We understand that not every office wants to purchase a license of Rhino. We are currently exploring our options for Revit (not Dynamo). We have been in touch with the Dynamo team too. There are minimum needs that should be provided from the Dynamo team before we can continue any meaningful development of the Dynamo packages. Until then we do not have a plan for continuing the development for Dynamo.

But also see this post:

Which path for a new LB/HB user (from Revit)?

Hi @lluj, The best possible approach is to use the new Revit plugin with our new upcoming Grasshopper plugins. In the new plugins the data is transferred between the platforms using the HBJSON format (https://github.com/ladybug-tools/honeybee-schema/wiki). [Use HBJSON for translation] This means you can load a model from Revit into Rhino/Grasshopper without loosing any data during the translation. [Translating Revit model to Rhino] I can add you to our early access group if you are intere…

-wim

[loicw]

Hi @wim,

Thank you for the links.
The plugin to transfer the data between the platforms using the HBJSON format seems promising.

It’s a pity that the Dynamo development is put on hold for the moment, but they seem to actively search for diverse solutions.

Thanks again for the help.
Best.