OpenGL cards and multiple windows / WinNT

[John Biddiscombe]

>
>Its hard (but not impossible) to imagine an event in the VTK and
>graphics card that could cause the pattern of black regions shown.
>Instead, this looks very much like two surfaces are being displayed
>that have the same coordinates but where one is either black or has
>its surface normals pointing away from the viewer. Few if any Z
>buffering systems could resolve them. Is this possible?

"Is this possible?"

No, there is one dataset only in the image, ScalarVisibility is on to show
the coloured spots, but there is just one set of polygons and no
possibility of two images being close. The terrain is a warped structured
points surface and no polygons lie "behind" the ones we can see.

The giveaway is that if I change the background colour to something else,
all the black regions change colour to match the background, it really is
plotting "nothing at all" in the black spots.

John B

Here's another with the background changed and no scalars visible, color
disabled
http://www.rcru.rl.ac.uk/~jab/temp/Image3.gif




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