[vtkusers] Terrain rendering problem

[Chris Scharver]

On Feb 3, 2004, at 10:14 AM, Georgios Katsaros wrote:

> The result is "almost" correct, except for the following intermittent 
> problem: When the "edges" of the terrain data are of higher elevation 
> than data closer to the center of the terrain patch, the internal data 
> is rendered "underneath" the terrain. So, instead of having a "valley" 
> in the middle of the terrain, there is a "mountain" under the terrain 
> model. The "valley" on the upper face is rendered as flat, with some 
> straight-line patterns.
> On the other hand, an island (where surrounding elevations are zero), 
> renders correctly.

We have noticed similar problems using vtkStripper on some triangle 
geometry. Edges, especially those that are higher than adjacent 
"internal" vertices, show sharp visual artifacts. Can you check the 
output of your pipeline before applying the stripper? It will be a lot 
slower, but see if those same visual artifacts are present. Our 
short-term workaround has been to simply not strip the data, which is a 
far from ideal solution.

Chris
--
Chris Scharver
Electronic Visualization Laboratory
The University of Illinois at Chicago
Ph: 312-996-3002   FAX: 312-413-7585
<http://www.evl.uic.edu/scharver/>