How do I get rid of the dark, pinched areas produced by my model?

[Mikael71 (Mikael)]

Hi everyone,

I’m currently modelling Roman captials as NURBS, in order to produce intaglios using BooleanDifference. The models’ side walls are generated using Sweep2. I’ve tried my best to keep curves consistent (running FitCrv Degree=3 and Tolerance=1 on all of them, as well as checking their directions with Dir and running Fair), but as you can see in the top section of the enclosed image, the letter serifs on the intaglio have darkened pinched areas, most visible in the blue circle, which I can’t see on the closed models. I’ve tried Rebuilding the surfaces and using Smooth, but the result remains the same. I’m not sure what to make of the Zebra rendering, as I’m no expert on the subject. My custom render mesh quality settings are shown below:

[jeremy5 (Jeremy)]

Hi Mikael,

As you’ve created the feet of the A with straight valleys, the sides won’t be lying at a constant angle to the surface, there will be a twist in them. I wonder if this is the cause of the effect you see?

When I once had to produce lettering like this, I elected to carve the sides at a constant angle to the surface, which led to curved valleys like this:

But while I’m an occasional typographer, I’m not a letter carver, so take what I say with a pinch of salt.

Regards
Jeremy

[Mikael71 (Mikael)]

Thank you, Jeremy.

I see where I’m going wrong now.

Regards,

Mikael