Bad Hull Mesh


#1

I have this hull surface. File attached. If I want to mesh it, regardless of setting I use, ( my favorite is all set to 0, except Maximum distance, edge to surface set at .001 ) each mesh created shows as bad object. Any idea why is this happening…? I’ve build entire ship around this hull believing that it’s perfectly fine. Until I had to export into stl… Although it seems on the final model, ( not the attached surface ) after original meshing if I reduce mesh by around 5% it reverted into a good object. Doesn’t work on this surface though…Bad Mesh.3dm (126.3 KB)


(Pascal Golay) #2

Hi Adam- - yes, I see - run RebuildMesh on the output… but we’ll see if we can figure out what is going on here. RebuildMesh destroys texture coordinates, so if these are needed, set a custom mapping object for the mesh and use the hull surface as the custom object.

So, what the mesher does not like is the location at the base of the bulb where the edge control points of adjacent edges are colinear with the corner point - this leads to an undefined surface normal at this location and it looks like the mesh is bad because of that. In general it is best not to have adjacent surface edges tangent to one another.

-Pascal


#3

Thanks Pascal,
yes I figured that the base of bulb is causing problem too. Funny because I’ve made many good hulls this way. In fact I just quickly moved few end points on couple of hull curves so their ends are not linear anymore and now meshing the hull does a good job. Bad MeshA.3dm (130.4 KB)