Spline mesh doesn't render when completlly vertical

I tryed to make a rope using spline, so I created a blueprint with spline component. The spline has a bunch of points, all arranged vertically. I added spline mesh between each two spline points via construction script. In the ‘add spline mesh component’ node, I changed the mesh and ‘forward axys’ to Z. All other settings remain on their default value.

When I added the object to the level, I can see and edit the spline, but it doesn’t render the spline mesh, unless I move some points and make the spline not vertical. In that case, the non vertical part of the spline properly displays the mesh, while the other parts are still not rendered.

UE4.18.3 This issue still exists! The problem occurs when tangent vector is set to (0;0;1).
Hacky workaround is to check if tangent vector is (0;0;1), then set it to (0.000001;0;1).


2 weeks in… I am so grateful for your comment. Thank you dude, YES!!! It’s finally working for me too!

Unreal 5.2 seemingly has this issue too. Just spent the last week stewing on it… going absolutely crazy. Keeping my tangents at 000 but you can fix it also by adding a similar offset to the position.

EDIT: While changing the tangent or position manually like mentioned above will work, the real problem is that the mesh has a messed up “up direction”. The real solution seems to be setting the spline mesh component’s up direction. In my example, since the spline is straight vertical, I just reference just one spline point and grab it’s direction and then played with the rotation on a particular axis.

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