POV-Ray : Newsgroups : povray.bugreports : strange experience with the perspective camera and very large height_fields Server Time
25 May 2024 11:17:48 EDT (-0400)
  strange experience with the perspective camera and very large height_fields (Message 1 to 1 of 1)  
From: MichaelJF
Subject: strange experience with the perspective camera and very large height_fields
Date: 8 Jun 2013 13:40:00
Message: <web.51b36b784773a944bd686c570@news.povray.org>
Hi to all,

I'm not sure if this is a bug, but I think this is the most appropriate group to
discuss my observation. I always wondered what I could do with the "puget sound"
data delivered by the Georgia Institute of Technology. The geology round of the
tc-rtc seems to be a good place to take a second look into this data. So I did.
The original height_field has a size of 16385x16385 which represents an area of
163.85 square kilometre, Mount Rainier nearly in the middle. To find a nice spot
I defined a spline following one of the arms of the sound ever looking at the
peek of Mount Rainier. In fact for some reasons (most likely I used an older
image) I scaled the height_field by 3 in x and z and with 0.12 in y (which is
the correct proportional value with the given dimensions of the original data
here). The camera should be along the spline in an animated sequence 2 meters
above the ground (0.000036 with my insane settings). If I use the original
height_field data and the original texture from the Georgia Institute of
Technology (and a blue background) I yield the following picture. What is
puzzling me is the blue part of a circle at the buttom of the image. In this
image the camera (perspective) is ABOVE the height_field (trace + <0,0.000036,0>
= 2 meter in y above ground with my scaling). How can the blue circle segment at
the buttom be explained?

I would like to depict a pyroclastic flow at a volcano. Mount Rainier is still
active enought to be able to produce something like that. Fortunatelly it didn't
happened so far to the people of Seattle and surroundings, unfortunatelly it
didn't happened since it would have spared us Windows 8 (Redmond is within the

Image in the p.b.i as usual.

Best regards,

Best regards,

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