Wasn't it Geodesic who wrote:
>Hi,
>Rendering a number of identical isosurfaces, I noticed that one of them was
>'missing'.  The problem seems to be based on a number of things - the
>placement of  the object, the camera position, and bizarrely, a rotation
>about the axis of symmetry which should produce no noticeable difference.
>Checking the messages thread, it claims that the maximum gradient found was
>0, and also lists all intersection tests with the isosurface as failing.
>
>The other isosurfaces appeared exactly as they should, even in areas that
>overlap where the 'vanished' isosurface should be.
>
>I'm using version 3.6.1, on Windows 2000

Do you get a warning displayed in the messages pane? I get this:

 Shutdown Warning: Evaluate found a maximum gradient of 0.000 and an 
 average gradient of 0.000. The maximum gradient variation was 0.000.
 It is recommended to adjust the parameters of 'evaluate' to:
 First parameter less than 0.000
 Second parameter less than 1.000 and greater than 1.0
 Third parameter greater than 1.000 and less than 1.0

I never really understood "eval", but if you use "maxgradient 250"
you'll see the object. POVRay will still put a warning suggesting a
higher max_gradient, but that's because there are tiny regions where y
is large and x and z are close to zero where the gradient becomes very
large indeed.

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message