Mmm . . . tasty Nucleus form finding

[Edit: Nucleus is no longer available in Vasari since it went to Beta]
Vasari 1.1 has the Nucleus cloth simulation add-in natively available in the mass family environment.  This is a first pass at incorporating a really powerful physics engine developed by the folks at Maya into Revit/Vasari via the API.  It takes advantage of only a portion of what can done with this tool, but it’s pretty interesting to see these sorts of shapes and interactions live in your BIM.
Basic Nucleus Workflow
[Since recording that video, meltedwellyface helpfully pointed out that the default 9.8  “gravity” value “is 9.8m/second, the rate at which a body falls due to gravity at the surface of the earth.”  Which makes my cranked up simulations more applicable to something like Jupiter, I suppose.]
Now that you have the basics, lets do something that stresses the system a little.  This video shows how to add a collider, and then some hacky ways to detach your resulting geometry from the plugin and do other operations on it. 
Nucleus Frosted Donut
One other caveat: There’s an unfortunate bug that Nucleus constraints don’t work with the metric template that shipped with Vasari 1.1.  The workaround and replacement metric template that can be download from here.  As always, proceed with caution with the labs previews.  Wear your hardhat, this a construction zone.


  1. Great tutorial and a great plug in. However, the fact that you need to delete the reference points in order to add voids is a huge deal breaker. You are unable to edit the surface manually or simulate when the points are deleted. You might as well import a static surface from Maya then. Let's hope and see if this issue can be resolved in the next release.

  2. Hi Rick, Don't get me wrong, in many cases you can cut nucleus geometry just fine, but in cases where it doesn't, this is a good workaround. In general, the surface created using "update surface" works just fine in cutting behavior. I don't particularly like that surface, I think that the smooth loft that is made by creating your own is better, and I'm demonstrating a workaround. I probably should have done a simpler example, with just cutting the “update surface”, but I didn’t think it looked as good.

  3. due to the immatureness of the make form command, your proposed lofting method often fails unfortunately. on the other hand, if you loft these (in Revit failing) lines in Rhino and reimport the surface, you can even apply the UV divide surface command and apply patterns on them.

  4. I like the idea to incorporate nucleus but looks like it needs quite a bit more work.

    One big one is why am I only limited to a rectangular surface mesh. Seem like I should be able create a surface, sub divide it and used that as my starting surface.

    One possibility your shape wasn't symmetrical was the wind. I couldn't see what your setting were. Also why is only presets for wind speed. Why not let me input a strength value.

  5. This is in the "Labs" section of Autodesk...so it is valid to have a limited functional plugin...

    Zach..if I could, why after downloading/running Vasari I don't see the Nucleus pull down? I see the other Vasari 1.1 plugins, just not the Nucleus...I did install the 64bit version today and it works with revit 2011...just not for Vasari...any thoughts?

  6. Hi Luigi,
    Are you looking in the mass.rfa envirionment? Nucleus is not available in the project/rvt environment.

  7. Hi Zach..yes, in Revit Architecture I get the nucleus drop down working no problem...but in Vasari 1.1, while in the mass editor, I don't get the pulldown for the nucleus tools. As far as I understand...in Vasari the nucleus should be automatically part of it..right? No additional plugin install...

    While in the mass editor in Vasari I have as a pulldown "Model, Analyze, Manage, Add-Ins and Modify" nothing else. When I go to the project environment of Vasari, I do have Planar Solar Radiation, Wind Rose...so I know I'm running Vasari 1.1 hmm...probably shouldn't send this type comments to your blog :s sorry

  8. Luigi, sounds like you are still looking in the rvt/project environment, just in the in-place mass editor. You will need to make a new mass family to access the nucleus tools.

  9. got it...sorry...yes, I was in the "in-place" mass editor...I thought the in-place mass editor was not the rvt/project environment...my bad! It works... I miss the face with the red cheeks...

  10. Nucleus can not work with metric mass ! Why not ?

  11. The metric template has some residue from a pre-release version of Nucleus. There is a workaround at the bottom of this post. Another workaround is to open the metric mass template, got to the Level 1 view, select and delete the point element that you see at the intersection of the ref planes, save the rfa and re-open it. Nucleus should work fine now, but you will have to do this for every new file.

  12. very cool donut! Gaming engine environments
    are the new frontier for BIM. ( check out TwinMotion, for example.)

    Just to be precise, g = 9.8 m/s squared.
    (on Earth, anyway.)


  13. love the idea behind this and the possibilities. running into a lot of bugs and i need more computing power.

  14. Hey guys,

    Great post, I was just wondering why I can't add constraints to my surface? I'm using the default metric mass template because those links above are dead. I also don't see any 'point element at the intersection of the ref planes'. Please help!

    Thanks in advance