How to fill an area between closed curves with black when curves on a surface?

Rhino Rhino for Windows
1

Hi,
projected a closed curve shape to a surface, wish to fill result with solid black, use Hatch but nothing appears.

Steve

2

Hatches are planar objects, if the boundary curve is non-planar, it gets projected to the CPlane. The hatch boundary also needs to be closed.

If you need a non-planar “hatch”, you will need to make a copy of the surface then trim it with the curve, and then color it as you need. You may even need to offset the “hatch” surface a bit to prevent a Moiré pattern from happening with overlapping surfaces.

–Mitch

3

Hi Mitch,
exploded surface, trimmed it ok…

Can I get a surface to go jet black under any lighting, as this is to represent a visual hole as black. using black as layer colour sees shades of grey normally.
Also its same as cyan surface it sits on so I see grey/cyan fragments ! as you say offset it a tad.

Steve

4

For shaded mode, try setting your display color to Hue=0, Sat=0 Val=1 (not 0)… that should be “pretty black”. Otherwise you can use SetObjectDisplayMode and set your object to Rendered (per-viewport setting), then apply a matte black material.

–Mitch