Given some input, biarc is not working

biarc component behavior is uncany.
in the following input, inputs are the results of a factor with value “0.43…”, it is working.

biarc is (92.1 KB)

when the value is slightly changed, for instance to “0.36…”, biarc is not working anymore. However, it should be working (a construct of the biarc is done without the biarc component).

biarc is (90.9 KB)

I apologize in advance for the behavior setting is complex. For the record, I was unable to reproduce the problem with simple inputs (see below).

biarc simple (10.3 KB)

Software information

Software versions
Rhinoceros version: 5.4 WIP (5E78w)
Rhinoceros path: /Applications/
IronPython version: not installed
WIP expiration: 16 June 2017
Language: en-FR (MacOS default)
macOS version: Version 10.12.5 (Build 16F73)


Third party kernel extensions
org.virtualbox.kext.VBoxDrv (5.0.16) 35F02C29-8027-3636-ACD2-6F171A50C1D8
org.virtualbox.kext.VBoxUSB (5.0.16) BD2570CD-7993-3635-BE1E-FAB977FFBD5C
org.virtualbox.kext.VBoxNetFlt (5.0.16) 2C1775A7-B7A3-32A2-9E8B-951C1B499870
org.virtualbox.kext.VBoxNetAdp (5.0.16) B108642D-2C95-3CB4-8D0B-01F867E60FBF

Hardware information

Computer hardware
Hardware model: MacBookPro9,1
Processor: Intel Core i7-3615QM CPU @ 2.30GHz
Memory: 4 GB
Architecture: Intel 64 bit

Video hardware
Graphics: NVIDIA GeForce GT 650M 512 MB
Memory: 512 MB
Screen size: 1440 x 900
Displays: Color LCD (111dpi 1x)

USB devices
Apple Inc.: FaceTime HD Camera (Built-in)
Apple Inc.: Apple Internal Keyboard / Trackpad
Apple Computer, Inc.: IR Receiver
Apple Inc.: Bluetooth USB Host Controller
Logitech: USB Receiver

Bluetooth devices

OpenGL information

OpenGL software
OpenGL version: 2.1 NVIDIA-10.17.5 355.10.05.45f01
Render version: 2.1
Shading language: 1.20
Maximum texture size: 16384 x 16384
Z-buffer depth: 24 bits
Maximum viewport size: 16384 x 16384

Implementation settings
Use texture compression: No

Appearance settings
Antialiasing: 4x
Mip map filtering: None
Anisotropic filtering: None

The problem appears to be that the tangents are parallel. Somehow the bi-arc solver is choking on that.
Looking into it now.

Hello, could you indicate if a correction is planned ?(full disclosure, i am a biarc addict ). Thanks and best regards, Thomas

Yeah I think it was fixed. Did you check with a recent Wip release? Of course nobody has converted any of my fixes of the past year or so to the Mac version, so that will still be broken until we figure out how to update it.

Hi, it does not work with latest WIP (Rhinoceros version: 5.4 WIP (5E119w)). Hope you can merge to mac version. best regards, thomas

Logged as RH-40336. This issue should get resolved once we have managed to figure out how to merge all of David’s changes in the past year into Grasshopper for Mac.

no good?

; )


Why did I not think of that?! :smile: Commit. Commit. Commit.

Wait, on second thought, I think you’re missing a Curtis and a Steve component.

1 Like

I am strungling with biarc in version 0.90076.
If both vectors are parellel sometimes biarc does not work?

If you’re on GH for Rhino 5 the bug is still there. It has only been fixed in GH on Rhino6 which have 1.0.xxxx version numbers.

Hey @Balazs-

Give this a try in the latest RhinoWIP and see if it works there. It should…if not, please let us know.