# Ray tracing the envelope of a building

Hi All,

I’m not even sure if this is possible to do and i haven’t had much luck in Dynamo myself but if anyone does know at least the first step i could probably work around the principles from that to develop it further.

The Goal

To re-create a model consisting of only the building envelope as a generic mass and fill in the internal area with one large “Space or Room”

No doubt i’ll continue to try and do this but thought some smart cookies might stop me from going down a rabbit hole too deep.

My two cents
Make a new empty model
Set it to be Room bounding
Draw a fence like wall outside the building a few meter away from it
Place a Room between the fence like wall and the building
Set the Room calculations to include volume
Do that for every Level
Extract the Room boundaries or faces in Dynamo
Take the inner boundary to create your Mass.

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Sounds like this is something worth Exploring

Could take me a while but ill mark as solved if it ends up working.

Thanks Marcel!

For something of this level of geometric complexity I’d consider looking into Rhino Inside and Grasshopper, especially if you’re going to generate/work with mesh.

I’m guessing this is for city planning requirements with a watertight mesh model or something similar. In my experience it’s always easier to roughly model the shell from scratch as a generic mass vs. try to automate - watertightness is very hard to achieve without errors using computation.

Hi Gavin,

The purpose of this is to export to an energy model to be read by design builder.
My theory is that if i can export a filled “Weather tight” mass for our ESD team to work from that it
saves them about a days work on every job.

Probably important to mention that the level of detail is extremely low (Ie; a mesh finish is not required)

Sectioning and defining spaces can be done afterwards with more ease one you have a shell to work from. because typically the level of detail on the Revit models we receive is at a concept or preliminary design level normally accompanied by some Autocad files for floor layouts)

interestingly i found that trying to do what i initially described here to be less helpful than i thought it would be, and have moved onto using the same principle but generating a conceptual mass instead of a “room” or “space” because in as an XML file this imports as a building block that the ESD engineers can work from with a lot more freedom.

I am still struggling a little bit with filling up the inside areas based on wall, floor, ceiling locations but i feel like ill over come this after a bit more work, i’ve placed it on the back burner while i work on billable work

i will update once i make some measurable progress for anyone else out there who might stumble across this.

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