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[IDV #KBZ-388612]: holes in some color filled contours of 3d grids

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  • Subject: [IDV #KBZ-388612]: holes in some color filled contours of 3d grids
  • Date: Thu, 02 Apr 2009 08:08:32 -0600
Hi Stu,
Sorry on the delay in the response. Your request dropped through the cracks 
here.

> Description of problem: Here is a case of a 3d grid displayed as color filled 
> contours. The level is set at -33 km, and the default contour interval is 
> 0.6. Holes appear in the data - no color regions. If you change the contour 
> interval to 0.5 the holes fill in.
> 
> Bundle attached; data is on the unavco geo server.
> 
> This was reported by two users this week.
> 
> 

Here is Don's explanation:

To fill in a contour, you have to have the next value to fill to,
so his contours need to go to 0.6*9 or 5.4.  In this case, it seems
like it's a plateau of 4.8 values.  If you just draw contours, you'll
see that there are circles of 4.8 around the holes.  In contouring,
lines are drawn at the edge of the change from one set of contours
to the other.  So in this case, it's the transition from > 4.2 to
4.8.  In filling, it knows to go from 4.2 to 4.8 because it fills
between the lines.  I'm not sure how it would know to fill in the
hole if there is not a next contour to fill to.  Since the range
only goes to 5, there is no next contour to go to or even look for.
Even though there is no 5.4 contour, the algorithm will fill to the
next value. 

A solution to this is to have the upper limit of the contouring go to the next 
interval step, e.g., 5.4

-Jeff


Ticket Details
===================
Ticket ID: KBZ-388612
Department: Support IDV
Priority: Critical
Status: Closed