POV-Ray : Newsgroups : povray.binaries.animations : Mysterious vanishing isosurface : Re: Mysterious vanishing isosurface Server Time: 26 Feb 2021 21:50:58 GMT
  Re: Mysterious vanishing isosurface  
From: Mike Horvath
Date: 9 Dec 2016 05:09:49
On 12/9/2016 12:02 AM, clipka wrote:
> Am 09.12.2016 um 03:36 schrieb Mike Horvath:
>> If I rotate the camera 90 degrees around the x axis, the isosurface
>> disappears.
>
> My guess would be that on the "bottom" side of the shape, the function
> has a much stronger gradient, so that when POV-Ray starts searching the
> contained_by volume for intersection points starting from that side, it
> finds incredibly huge values and thinks, "oh, I must still be VERY far
> from the surface" -- advances a good deal, _skipping_ over the actual
> body of the shape, and finds itself still outside, concluding that there
> is no shape at all.
>
> You must either increase max_gradient to fit even that portion of the
> shape, or somehow find a way to get a nicer gradient down there.
>

Is there any "adaptive" form of max_gradient, so the setting is only 
high where needed?

Mike


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