Revit’s divided surface bug

2 min read
Share on twitter
Share on linkedin
Share on facebook
Share on email

One of the reasons that Rhino remains so popular amongst designers is Revit’s primitive conceptual modelling tools. Below is a clear example of Revit’s limitations when it comes to conceptual modelling and how Rhino can help. Special thanks to David Baldacchino from do-u-revit for contributing to this solution. 

Planar = Cropped UV divisions

A known ‘bug’ within Revit is how planar trapezoidal surfaces are divided. Revit takes the liberty of ‘optimising’ the divisions by treating the surface as a trimmed surface and cropping the UV divisions. There is no way to prevent Revit from doing this, even if you are in Dynamo. This automation can cause significant problems, as often one needs the UV divisions to follow the surface, not some imaginary trimmed surface.

Planar surface

Non-planar surface

There are a few workaround options to make the trapezoidal surface with a skewed UV grid. Unfortunately, none of them are great.

Workaround 1: Minimal non-planarity

The first workaround is to displace one of the vertices a tiny amount, say 1mm so that the surface is not a real plane. This workaround is not ideal and very inaccurate.

Workaround 2: Use intersections

The second workaround is to set the number of ‘V’ divisions to zero, and use intersects instead. To do this:

  • Take the top and bottom edges and divide the path.
  • Set the number of points you want. This number will be the V grid divisions.
  • Add reference lines between these nodes. Note: these cannot be used as intersects as they are not plane-based.
  • Create reference planes by picking these reference lines and use them as intersects. 

Intersecting planes

Divided surface

Conclusion

Neither workaround is great but until Autodesk decide to fix the problem, and it is a problem, this is the best we can do.

Share on twitter
Share on linkedin
Share on facebook
Share on email

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Balcony Area and Depth with Dynamo
Premium

Min balcony area and depth

Verify a balcony’s minimum area and depth with Dynamo for compliance with the NSW Apartment Design Guide and SEPP65 requirements.

Renumber Balconies
Premium

Renumber balconies

A Dynamo workflow to renumber balconies based on their associated apartment room to assist in documentation and compliance checking.

Copyright​

© 2021 Parametric Monkey
Parametric Monkey and the Parametric Monkey logo are trademarks of Parametric Monkey Pty Ltd.

CONTACT US

Drop us a message and someone from our team will be in touch with you shortly.

BOOM!

Thank you for your interest. Someone from our team will be in touch soon.

WORKSHOP APPLICATION

To find out about upcoming public workshops or to organise a private workshop, please submit the following contact form and we’ll be in touch soon.