POV-Ray : Newsgroups : povray.beta-test : Bicubic patch type errors : Bicubic patch type errors Server Time
31 Jul 2024 06:21:55 EDT (-0400)
  Bicubic patch type errors  
From: Mike Hough
Date: 6 Sep 2001 20:30:17
Message: <3b981519@news.povray.org>
The parser seems to need some cleanup.  Take this scene:

#include "colors.inc"

camera {location <0, 0, -2> }

light_source {<10, 10, -20> color White}

#declare test_pigment =
pigment {
gradient y
frequency 6
color_map {
[0 color Blue transmit .5]
[1 color Red transmit .5]
}
}

/* righty patch */

#declare test =
bicubic_patch {
type 2
accuracy .1
uv_vectors <0, 0>, <.5, 0>, <1, 1>, <0, .5>
<-3, -3, 0>, <-1, -3, 0>, <1, -3, 0>, <3, -3, 0>,
<-3, -1, 0>, <-1, -1, -3>, <1, -1, -3>, <3, -1, 0>,
<-3, 1, 0>, <-1, 1, -3>, <1, 1, -3>, <3, 1, 0>,
<-3, 3, 0>, <-1, 3, 0>, <1, 3, 0>, <3, 3, 0>
uv_mapping
scale 1/6
pigment {test_pigment}

}

object {test} /* test that patch data is being copied correctly */

This produces the error "bad patch type in ALL_Bicubic_Patch_Intersections"
following the message that there is one frame level object in the scene.  It
should just say bad bicubic_patch type or revert to the old behaviour of
using the default value.  An example is changing the type to 4 or any other
integer value and having it render without any errors.  In this case it
finishes parsing and begins rendering before the error is given.

Now change the patch type to 0 or 1 and it renders without any errors.  It
should produce an error because accuracy is a tuning value for the type 2
and 3 patches from MegaPOV and doesn't seem to belong in bicubic_patch.  If
it is, it isn't documented.


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