I extruded a circle, positioned perpendicular to the first line, and used a path consisting of connected straight-line and arc segments. However, the resulting solid becomes distorted during the extrusion process.
Could you please help me resolve this issue? In Revit, performing a Sweep along the same path works correctly without any deformation, so I would like to understand why the geometry is being distorted in this case and how it can be fixed.
sometimes curves seems have same direction but not, well it has same direction but in the oposite sense, not sure if i’m expresing me correctly!!
Me when someone posts a geometry question but doesn’t give sufficient context to reproduce:
Generally speaking, addressing geometry creation issues pretty much always requires the context leading into the problem in order for us anyone to help. Without that context we can only guess. The easiest way to provide such is to share a .dyn with the two geometry bits serialized into a Remember node. You could also display the preceding geometry in Dynamo’s preview window; create an image of your workspace; or write some simple design script to reproduce the issue.
Possible causes:
hi @jacob.small, @gilberto.arechigaiba
Thank you for your explanation. I understand the possible causes of this issue, including profile rotation along the path, inconsistent sampling, profile-path relationship degradation, imported geometry limitations, and coordinate precision problems.
However, my main concern is how to overcome or mitigate these issues in Dynamo. Have you encountered a similar situation before?
In my case, I am trying to sweep/extrude a circular profile along a path consisting of multiple connected lines and arcs. The same path works correctly when using Revit’s native Sweep function, but the geometry becomes distorted when generated through Dynamo.
Could you share any practical solutions or workflows that have worked for you? For example:
I would appreciate any suggestions or examples from your experience.
My guess would be coordinate precision/unit problems.
Does it work with geometry smaller or closer to the origin ?
For these issues, I’ve sometimes switched the model to different units (say millimetres–>metres) and adjusted Dynamo data to suit
Seeing that bit of geometry makes me think the same @Andrew_Hannell.
@BIM_VIET what is the maximum point of the bounding box which covers the resulting solid, and is geometry scaling set to medium?
Hi @BIM_VIET,
I think the main issue is related to how Revit and Dynamo generate coordinate systems along a path. They do not use Rotation Minimizing Frames (RMF), which are designed to prevent unwanted rotation of the cross-section along the curve. As a result, a twist can occur when the path changes direction or curvature.
For this reason, we typically do not use the standard Sweep operation for modeling bridges and tunnels. Instead, we place adaptive family instances directly in the project environment, without hosting them to the path. The adaptive components generate the cross-sections along the alignment while maintaining the desired orientation and avoiding the twisting problem that is commonly encountered with sweeps.
This approach provides much better control over the cross-section orientation and is the standard workflow for complex linear infrastructure such as bridges and tunnels.
yeha i agree with the guys, normally wen you ask for the curves on certain existing geometry you have not control of the direcction or internal propertys for the curve, sometimes when you ask to create geometry based on the path of a curve or directly place a serie of CoordinateSystem you get this geometry very messy, specially when the path is made of several curves, perhaps that is what you are getting, i don’t have an strategy for you, most of the time i manage it custom depending on the script’s requirements, which is very time consuming. I hope this can helps you!!
