Re: surface elements for transparent_solids.dem

[Daniel J S. <dan...@ie...>]

Daniel J Sebald wrote:
> One thing I notice when the fill is solid is that along some of the
> edges of the Kuen's surface example are some oddly shaped surface
> elements.  For example, along the orange/red edge of the surface are
> some elements that appear to be tiled in a direction counter to the
> reset of the element flow.  Is this a known effect, either in general
> or for this particular manifold?  Is there some cusp along that upper
> ridge that causes this?

Looking at this more closely, it does seem like a bug.  If one plots in x11 and uses the mouse to pan about, the manifold gets very "thin" along the locations where the strange elements appear.  Could this be an effect where a tile from an underlying surface is coming through the top surface?  Could there be a roundoff error in a conditional test somewhere that the gnuplot algorithm thinks an element should come through and above a top surface when it really shouldn't?

Dan