Error while creating the geometry

[Rajkanu]

Dear STKO Team,
I am trying to model an arch barrel divided into three curved regions

Screenshot 2025-12-16 084741.png (236.93 KiB) Viewed 437 times

. When I extrude the arch I encounter an error ( Error - MpcMeshEdgeControlsVRep::buildGraphics() called without a VisualRepresentation . Additionally, when I merge the model the surface is automatically removed. Could you please help me resolve this issue? I used the spline command to create these curved regions- are there any alternative methods to create three curved regions in an arch

[STKO Team]

This happens when some portions of your geometry are invalid.
I don't know the procedure you followed to build your model, but I would first draw the base surface for the vault, then I would draw in 2D the spline for the cut. The I would extrude the vault into a solid, the curve into a shell, and use it to cut the vault using the merge command

[Rajkanu]

Thanks for your reply.
I followed the similar procedure you suggested, but when I merge, I’m not getting three individual solid pieces. Instead, I get a single solid, whereas I need three separate solids. Also, after merging, the geometry becomes uneven there is some opening in the geometry. so please help me with this issue. I’m sharing my file with you pls check it and if possible, give me detailed procedure.
Thank you

[STKO Team]

Here I show the steps you need.
But it's all about: creating profiles and sweep them along a spine, merge, remove faces and a final vertical extrude