Part of Perspective Display in Rhino Appears to Be Missing

All,

I am designing a steam locomotive cab in 1:32 scale. My model looks like it has a hole in it in Perspective View. I looked at the model in Shapeways, Netfabb and Meshlab and it looks okay to me. This is, there are no missing sections of the model exterior. The model has been Booleaned.

I’ve attached images of the full model and views of the affected areas in Rhino, Netfabb, Meshlab & Shapeways.

Thanks for any comments, suggestions or derisive remarks.

Best hopes on a Sunday,

Hilary Smith
Pacific NW





Usually these fabrication tools fix the gaps and issues with model. If you select the troublesome object and run _check. What do you get?

Also share a 3DM file so I can help you

When parts in Rhino ‘go transparent’ like you show in your images, it usually means that there are some bad edge trims in there - which might be a result of joining surfaces with edges out of tolerance, Boolean operations with similar issues, etc. Because of the bad trims, Rhino has trouble creating a render mesh in that area (necessary for shaded display modes), so the objects show up in wireframe only. One clue to this being the problem is if you explode the object, the surfaces miraculously become shaded again. It is also possible that Rhino acknowledges that this is a bad object - if it lights up when you run “SelBadObjects”. But this isn’t always the case.

To fix it you will need to extract the affected surfaces and those surrounding them, rebuild the edges and then start joining stuff together again. You will probably find the spot where it goes bad, in that case the surface(s) in question will need to be analyzed to understand why the edges are out of tolerance and then remade to within tolerance.

Exporting a mesh from those non-fixed objects may be a little risky, as since Rhino is having trouble creating a render mesh, it might also have trouble creating a correct export mesh. If an automatic correction is applied in the incoming program, it might not do exactly what you want. Better to fix the object in Rhino before exporting (IMO).

Guys,

I am very grateful to tay.0 and Helvetosaur for the comments and suggestions.

Rather than try to solve this issue, I’m going to cut out and replace the offending volume and move on.

Many thanks,

Hilary Smith
Pacific NW

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