Mid-summer OpenVSP (at least in the Northern Hemisphere) — a handful of features and some nice bug fixes.

Copy/paste of XSec and XSecCurve now works across different Geom instances and Geom types. So, you can copy an airfoil from one wing and paste it on another — or paste it into your fuselage (or XSec type SubSurface).

Conformal components are now detachable from their shape parent. This allows them to be moved around the tree in the Geom Browser — which allows them to be attached to some other component. In a special case, if the detached conformal is an immediate child of a Hinge, it will be attached to the hinge (so it moves with the hinge), but it can get its baseline position from its shape parent. This enables using conformals for moving control surfaces or other articulating parts of the aircraft.

A new AeroCenter geometry analysis was added. This analysis will calculate the location of the incompressible aerodynamic center of a single wing in isolation. It will actually fire off a quick set of VSPAERO analyses and then calculate the AC position from those.

Inspired by a conversation at Aviation, I’ve added an alternative distance metric to the interference checks. Now, instead of using a scaled volume when the objects overlap, we calculate the maximum of the minimum distance between the faces of the overlapping region. This maximin metric will be closer to smooth (not just continuous) when an object transitions from non-interfering to interfering. This may work better for your optimization process. However, it does not extend to the situation where the interfering geometry is entirely contained within the other (which the old metric handles). Both calculations are available, use one – use them all!

I’ve embellished the names of a bunch of the Geometry Analyses in the GUI. This feature was originally called ‘Interference Checks’, so names like ‘External’ and ‘Packaging’ seemed complete. When The overall name was changed to Geometry Analyses, that context was lost. Now they are called things like ‘External Interference’ which should be more clear.

There was a small improvement made to the accuracy of the mesh-mesh minimum distance calculation done in several Geometry Analyses. Nobody will ever notice, but I feel better about it.

X3D files will now be written with split surfaces. This will improve the normal vectors near corners. Which will improve the visualization of models on the OpenVSP Airshow.

When you open a file set to auto-show the Vehicle Notes from the command line (or by double clicking if you’re set up for that), the notes will now actually show.

Plotting -Cp from VSPAERO is now less fugly.

I updated the Clipper2 library to the latest version hoping that it would fix some issues. It did not, but we’re keeping the updated version anyway.

There was a problem where retractable or stowed landing gear attachment points would not update when the Gear itself was moved. That is fixed.

The update process for hinges and conformals (and other step-children) was cleaned up a bit. Some scenarios should update faster now.

I had my friend Claude do some random cleanups of compiler warnings and other build system issues. This included some cleanups of the API docs and examples. I don’t trust him much for ‘real’ dev work on a project of OpenVSP’s size and complexity, but for stupid stuff like this, he is great.

GitHub Actions finally has an Ubuntu 26.04 runner, so we’re going to give that a go. They deprecated 22.04 a while back, so that one is already gone.

Features:

• Copy/paste XSec & XSecCurve across Geoms and Geom types
• Detachable conformal components with special treatment of hinges
• AeroCenter geometry analysis added
• Maximin interference metric
• X3D files now written with split surfaces – prettier normal vectors

Build System:

• Clipper2 updated to latest version
• Ubuntu 26.04 build added

Bug Fixes:

• Geometry Analysis names improved in GUI
• Improved accuracy of min-distance mesh calculations
• Auto-show vehicle notes now works from command line and double-click
• Better plotting of -Cp for VSPAERO slices
• Gear attach point update now works when Gear itself is moved
• Faster update for some hinge/conformal combinations
• Compiler warnings and build system cleanups