POV-Ray : Newsgroups : povray.beta-test : Known Bugs 17 Dec 2001 Server Time
30 Jul 2024 08:21:05 EDT (-0400)
  Known Bugs 17 Dec 2001 (Message 1 to 5 of 5)  
From: Mike Williams
Subject: Known Bugs 17 Dec 2001
Date: 17 Dec 2001 15:11:58
Message: <5uh5UFARElH8Ewkd@econym.demon.co.uk>
Blob problem (job000189)
and Blob : Toward a solution
(blob surface develops holes when "radius" is very small)
http://news.povray.org/3b99052c@news.povray.org
http://news.povray.org/3B991C90.D715B7A3@free.fr

Superellipsoid epsilon to big ? (job000190)
(strange dark patches occur on a superellipsoid when the east-west-
exponent is set very small)
http://news.povray.org/3b992a81@news.povray.org

Additional (?) blob bug
(blob component disappears when radius is 317 or greater)
http://news.povray.org/Xns9115B92CF7D8ACQ@204.213.191.226
(also reported as: Blob rendering error (job000136))
http://news.povray.org/Xns91203DC7F3CCQ@204.213.191.226

Small window title bug
(Title switches back to "POV-Ray for Windows" after minimize or
restore.)
http://news.povray.org/3ba92966$1@news.povray.org

sin(X)^sin(X) -> crash! (job000179 and job000180)
http://news.povray.org/3baf7992@news.povray.org

Spline bug (job000182)
(The spline path is all wrong when certain time values are used.)
http://news.povray.org/3bb41dc8@news.povray.org

Strange spline problem (job000181)
(Changes from render to render. Control points are sometimes missing.)
http://news.povray.org/Xns9136AC2E64F60seed7@povray.org

Highlight bug (job000137)
(highlights are sometimes visible where they should be in shadow)
http://news.povray.org/3bb4cf08@news.povray.org

Macro bug (job000146)
(POV can dereference a deallocated pointer if you return a local from a
macro.)
http://news.povray.org/3BB4ED11.8EC69CEC@hotmail.com
(also reported as: strings operations crash with both compiles)
http://news.povray.org/e3piut8anmf4cli4pnfmstadgc3nleqvb2@4ax.com)

Radiosity sampling, with fix method (job000177)
(radiosity sample counter is reset to the start every time, sampling
artefacts are produced)
http://news.povray.org/3BC5A13E.9C022BD6@reading.ac.uk

Slow rendering when using +ua and antialiasing method 1 (job000191)
(No details available)
http://news.povray.org/3bbf6347@news.povray.org

Delayed syntax checking (job000192)
(declare without the "#" can cause a much later line to fail to parse
Parser will ignore the first token following old-style declares without
a #.)
http://news.povray.org/AM3LOAABMO27EwFh@econym.demon.co.uk

[bug] orthographic camera bug?
(objects sometimes disappear when the orthographic camera is used)
http://news.povray.org/3bdca5eb@news.povray.org

Bug: dispersion_samples affects photon brightness (job000193)
http://news.povray.org/MPG.1631c5fca936293298969e@news.povray.org

Jpeg and memory problem during animations (job000194)
(It seems that some memory is not properly released between frames when
a jpeg file is used)
http://news.povray.org/3be2ef0d@news.povray.org

Bug with blobs and media
(possibly related to  blob surface develops holes when "radius" is very
small)
http://news.povray.org/3be5f0b2@news.povray.org

Render Window Bug
(Render window pops up when application minimised, after which the
application doesn't open when clicked on the task bar.)
http://news.povray.org/3bde157e@news.povray.org

Povray main window disappears during rendering
(Possibly the same as the above)
http://news.povray.org/3c1350f4@news.povray.org

Another strange photon behavior (job000195)
(a: bright colored caustics. b: holes/circular black spots)
http://news.povray.org/MPG.16510f3e44067d3f9896ae@news.povray.org

panoramic projection bug? (job000196)
(When "angle" keyword within camera statement appears after "panoramic"
keyword then looks like ignored.)
http://news.povray.org/avnfut8fof5ualgf8hnrtpl1knlg8828sp@4ax.com

Black outline in smooth meshes
(The outline of smooth meshes exhibit black dots or areas (which go away
with double_illuminate))
http://news.povray.org/3bf6794e$1@news.povray.org

User_Abort_Command
(User_Abort_Command does not seem to work at all)
http://news.povray.org/Xns913D9F7268736seed7@povray.org

First report from bugreports
http://news.povray.org/u12outsm2kso3k5ef4lp26ogm5cvsm46ge@4ax.com

Re: trivial question on topic
(Poly Object Bug: heart has a dark line of artifacts)
http://news.povray.org/3BEBEB4C.CA854309@pacbell.net

Camera is off by half a pixel
http://news.povray.org/3bccc696@news.povray.org

Light_sources in light_groups don't cast shadows
(rendering without light buffers (-UL) puts the shadows back)
http://news.povray.org/3bfd4d63@news.povray.org

Save during render
(is very slow)
http://news.povray.org/jhaiduce@engin.umich.edu

double_illuminate only works with direct lighting
http://news.povray.org/3BF6F1FE.D21B0C6@oreka.com

no_image, merge and shadows
(setting no_image to an object in a merge causes that object to stop
casting shadows)
http://news.povray.org/vqfd0ucm5276q9j8sdh34afjliapc1kj0n@4ax.com

Isosurfaces *much* slower in beta 7?
(isosurfaces with "evaluate" are now very slow)
http://news.povray.org/3bdf24b3$1@news.povray.org

rand.inc VRand_In_Sphere flaw
(VRand_In_Sphere doesn't give uniform distribution)
http://news.povray.org/3bc64790$1@news.povray.org

problem with normals/functions: crash!
(if an isosurface is the first function parsed, then things go horribly
wrong)
http://news.povray.org/MPG.16724448f4beb4ad9896c3@news.povray.org

Isosurface : 2 bugs
(int() causes crash)
http://news.povray.org/3c082dbe@news.povray.org

IsoCacti.pov
(displays 754 evaluate warnings, most with incorrect values)
http://news.povray.org/3c08c36c$1@news.povray.org

Re: triangle texture interpolation
(the second texture is on the first point and the third texture is used
on the second and third points)
http://news.povray.org/3C0A8288.DDA0905B@free.fr

Blob component textures transformed twize
http://news.povray.org/3bf70645@news.povray.org

2 Win GUI bugs + nitpick
(Double-clicking a file in explorer that file isn't opened in the
instance that is already running)
http://news.povray.org/3C073446.3020104@NOzSiPpA.Mto
(also reported as: Problems starting Beta8 from Command Line)
http://news.povray.org/3c0abb67@news.povray.org

Keep Single Instance (always does, no matter setting)
http://news.povray.org/3c0b0881$1@news.povray.org

Re: Workaround for function problems in beta 8 without scene file
modification
(using Include_Header in povray.ini crashes in some circumstances)
http://news.povray.org/Xns9170BB3381723CoridonHenshaw@204.213.191.226

Crash with no objects in scene
http://news.povray.org/3bd985b0@news.povray.org
(also reported as http://news.povray.org/3C19B9EA.D2E16FBC@gmx.de

bug in sphere_sweep for removing parts of an object
(discontinuous normals on inverse of sphere_sweep)
http://news.povray.org/3C1A5D47.EA38F6E5@amc.uva.nl

        BUGS FIXED IN NEXT BETA

image_pattern
(image_pattern produces brightness in range 76-255 instead of 0-255)
http://news.povray.org/3c09ff34@news.povray.org

o_shapes.pov (\scenes\portfolio) Beta 7 and 8
(Circle_Text and Supertorus examples have become incorrect)
http://news.povray.org/3C0A386B.7D3751C@compuserve.com

Bug with intersection stack (with crash)(job000175)
http://news.povray.org/5f13rtc0v0rso4fk7lut5e0980qa9g756b@4ax.com

Alpha problems: text is not antialiased (job000187)
(black objects are not antialiased on Unix and Windows versions, alpha
is not correctly output on Mac)
http://news.povray.org/3bea5a84$1@news.povray.org

hf_gray_16 + png creates wrong output image (job000173)
(global_settings {hf_gray_16} causes "Cannot open output file")
http://news.povray.org/3BA3BAE6.4671C0BB@free.fr

Slow render time after several runs
http://news.povray.org/3bd40c6d$1@news.povray.org

        FEATURE REQUESTS IMPLEMENTED IN NEXT BETA

Focal blur aperture has no effect with camera types other than the
persective one
http://news.povray.org/3bceb66d@news.povray.org

-- 
Mike Williams
Gentleman of Leisure


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From: Warp
Subject: Re: Known Bugs 17 Dec 2001
Date: 17 Dec 2001 16:22:46
Message: <3c1e6226@news.povray.org>
Mike Williams <mik### [at] nospamplease> wrote:
: Highlight bug (job000137)
: (highlights are sometimes visible where they should be in shadow)
: http://news.povray.org/3bb4cf08@news.povray.org

  By the way, I have the feeling, that this is may be a "bug" not worth
fixing.
  Why? It is extremely rare that one finds this behaviour (I have never seen
it in *any* of my scenes; I have never had a scene such that this would be
seen). Of course that's no reason to not to fix it, but I have the feeling
that adding a check for this could slow down all specular/phong calculations.
  I don't think it's worth slowing down the rendering of *all* scenes which
use specular/phong just because in one case in a million you might find this
little annoyance.
  Of course if a fast solution is found, then it's worth fixing, but somehow
I have the feeling that there might not me a fast solution (fast meaning
for example just few multiplications and additions).


-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -


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From: Rune
Subject: Re: Known Bugs 17 Dec 2001
Date: 18 Dec 2001 13:33:41
Message: <3c1f8c05@news.povray.org>
"Warp" wrote:
>   By the way, I have the feeling, that this is may
> be a "bug" not worth fixing.

You know, in an earlier version of POV-Ray (maybe 3.0?) the problem existed
for reflections too. That was fixed, but for some reason it wasn't fixed for
the highlights.

And for a simple demonstration, try to look a this sunrise-like image:

light_source {<0,-10,100>, color 1}
plane {
   y, -1
   pigment {color <0.5,0.5,1.0>}
   normal {bumps 1}
   finish {phong 1}
}

The highlights are visible even though the light_source is *below* the
horizon! I certanly don't call that a small problem.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated Nov 5)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk


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From: bob h
Subject: Re: Known Bugs 17 Dec 2001
Date: 18 Dec 2001 14:04:08
Message: <3c1f9328@news.povray.org>
"Rune" <run### [at] mobilixnetdk> wrote in message
news:3c1f8c05@news.povray.org...
> "Warp" wrote:
> >   By the way, I have the feeling, that this is may
> > be a "bug" not worth fixing.
>
> You know, in an earlier version of POV-Ray (maybe 3.0?) the problem
existed
> for reflections too. That was fixed, but for some reason it wasn't fixed
for
> the highlights.
>
> And for a simple demonstration, try to look a this sunrise-like image:
>
> light_source {<0,-10,100>, color 1}
> plane {
>    y, -1
>    pigment {color <0.5,0.5,1.0>}
>    normal {bumps 1}
>    finish {phong 1}
> }
>
> The highlights are visible even though the light_source is *below* the
> horizon! I certanly don't call that a small problem.

I know I would call it a problem enough to be fixed if it's going to affect
scenes in unexpected ways like that shows.  Is this really highlights
causing it though?  Looks to be more a highlighting+normals bug to me.  I
haven't seen the effect while normals don't exist.
--
text{ttf"arial""bob h".1,0pigment{rgb 7}translate 7*z}


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From: Rune
Subject: Re: Known Bugs 17 Dec 2001
Date: 18 Dec 2001 17:00:46
Message: <3c1fbc8e@news.povray.org>
"bob h" wrote:
> Is this really highlights causing it though?
> Looks to be more a highlighting+normals bug to me.

Correct, it is a highlights+normals bug. I thought I had pointed that out,
but looking at my bug report now it seems like I forgot it. :(

The problem is that while the angle between the direction to the light and
the perturbed surface normal may be less than 90 degrees, the corresponding
angle for the unperturbed surface normal may not, and this can cause the ray
to go out on the wrong side of the object.

For reflections, code has been added to deal with those situations, but not
for highlights for some reason.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated Nov 5)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk


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